In this guide we will be installing Debian 9 (aka stretch) on a physical server with 4 disks. The role of this machice is to be used as a Storage/NAS system. We will create a software RAID 10 setup, with LVM and LUKS full disk encryption. Our goals:

  • Install a Debian 9 with RAID10/LVM/LUKS.
  • Secure SSH.
  • Enable Firewall (UFW).
  • Setup bonding with the two network cards.
  • Setup remote system unlock with dropbear and initramfs.
  • Setup disk-monitoring with smartmontools and mdadm.
  • Setup kexec for faster reboots.

Computer specs

  • Type: HP ProLiant MicroServer
  • CPU: AMD Turion(tm) II Neo N40L Dual-Core Processor
  • RAM: 2GB
  • Disks: 4x3TB SATA
  • Network:
    • Broadcom Limited NetXtreme BCM5723 Gigabit Ethernet PCIe (on board)
    • Intel Corporation 82574L Gigabit Network Connection (extra)


  • Server IP:
  • Netmask:
  • Gateway IP:
  • DNS IP:
  • Hostname:

Install Debian stretch

Basic Settings

It would probably be more clear if there were screenshots for each step, but this was an installation on a physical server and taking photos for each step, opposes my laziness :). Just follow the instructions and you will be fine.

  • Choose: Install
  • Language: English
  • Country: other
  • Europe: Cyprus
  • Country to base default locale settings: United States
  • Keymap to use: American English
  • Primary network interface: enp3s0: Broadcom Limeted NetXtream BCM5723 Gigabit Ethernet PCIe
  • Let it get an IP from DHCP
  • Hostname: storage
  • Domain name:
  • Root password: SomethingBigAndUnpredictable
  • Re-enter password to verify: SomethingBigAndUnpredictable
  • Full name: Sysadmin
  • Username: admin
  • Choose a password for the new user: AlsoSomethingBigAndUnpredictable
  • Re-enter password to verify: AlsoSomethingBigAndUnpredictable
  • Select your time zone: Asia/Nicosia
  • Partitioning method: Manual

Feel free to adjust the above according to your own preferences.


There are 4 disks of 3TB each (3.0 TB SATA):

  • SCSI1 (0,0,0) (sda)
  • SCSI2 (0,0,0) (sdb)
  • SCSI3 (0,0,0) (sdc)
  • SCSI4 (0,0,0) (sdd)

Not really SCSI but SATA in fact.

Partition the devices

First create the reserved BIOS Boot area:

  • Select the free space of sda and ‘Enter’
  • Create a new partition
  • New partition size: 512 MB
  • Location of new partition: Beginning
  • Use as: Reserved BIOS boot area
  • Done setting up the partition

Then create a raid partition for /boot:

  • Select the free space of sda and ‘Enter’
  • Create a new partition
  • New partition size: 512 MB
  • Location of new partition: Beginning
  • Use as: physical volume for RAID
  • Done setting up the partition

Lastly create the raid partition to be used by the encrypted volume:

  • Select the free space of sda and ‘Enter’
  • Create a new partition
  • New partition size: 3.0 TB
  • Location of new partition: Beginning
  • Use as: physical volume for RAID
  • Done setting up the partition

Repeat the above steps for sdb, sdc and sdd.

Setup Software RAID 10

First select ‘Configure software RAID’ and follow these steps:

  • Write the changes to the storage devices and configure RAID? Yes

The we create the software RAID (MD) devices. First we create device md0 for /boot:

  • Create MD Device
  • RAID10
  • Number of active devices inn the RAID10 array: 4
  • Number of spare devices inn the RAID10 array: 0
  • Active devices for the RAID10 array (use ‘Space bar’ to select)
    • /dev/sda2
    • /dev/sdb2
    • /dev/sdc2
    • /dev/sdd2
  • Press ‘Continue’ when done.

Then we create the software RAID device to be used for the encrypted volume (md1):

  • Create MD Device
  • RAID10
  • Number of active devices inn the RAID10 array: 4
  • Number of spare devices inn the RAID10 array: 0
  • Active devices for the RAID10 array (use the ‘Space bar’ to select)
    • /dev/sda3
    • /dev/sdb3
    • /dev/sdc3
    • /dev/sdd3
  • Press ‘Continue’ when done.

  • Press ‘Finish’ when done.

Create the /boot volume

When done press ‘Finish partitioning and write changes to disk’.`

When finished you will see a ‘RAID10 device #0 1GB Software RAID device’:

  • Select: #1 1.0GB
  • Use as: Ext4 journaling file system
  • Mount point: /boot
  • Done setting up the partition

Setup the encrypted volume

We will be using the software RAID /dev/md1 device for the encrypted volume.

Now select ‘Configure encrypted volumes’ and follow these steps:

  • Write the changes to disk and configure encrypted volumes? Yes

  • Create encrypted volumes
  • Select: /dev/md1
  • Erase data: yes (this will take a long time)
  • Done setting up the partition

  • Write the changes to disk and configure encrypted volumes? Yes
  • Finish
  • Encryption passphrase: MyVeryLongEncryptionPassphrase
  • Re-enter the passphrase to verify: MyVeryLongEncryptionPassphrase

Setup LVM

Next we select the ‘Configure the Logical Volume Manager’ option and follow these steps:

  • Write the changes to disks and configure LVM? Yes

  • Create volume group
  • Volume group name: VG00
  • Devices for the new volume group:
    • /dev/mapper/md1_crypt

Then we create the Logical Volumes (LV). First let’s create a SWAP volume:

  • Create logical volume
  • Volume group: VG00
  • Logical volume name: SWAP
  • Logical volume size: 2048MB (2G is more than enough for this system)

Lastly we create the system (ROOT) volume. On an enterprise installation we may want to use different volumes for /usr, /home, /var, etc but for a home installation we will be fine to use just one.

  • Create logical volume
  • Volume group: VG00
  • Logical volume name: ROOT
  • Logical volume size: 5996818MB (All available space)

Press ‘Finish’ when done.

Start the installation

After all the steps are completed these Logical Volumes will be present on the system:

  • LVM VG VG00, LV ROOT 0 6.0 TB
  • LVM VG VG00, LV SWAP 0 2.0 GB

Create the ROOT filesystem

Under the ‘LVM VG VG00, LV ROOT 0 6.0 TB’ line select the ‘#1 6.0TB’ option:

  • Use as: Ext4 journaling file system
  • Mount point: /
  • Done setting up this partition

Create the SWAP space

Under the ‘LVM VG VG00, LV SWAP 0 2.0 GB’ line select the ‘#1 2.0GB’ option:

  • Use as: swap area
  • Done setting up this partition

Now we are ready to write the changes and start the installation. Press the ‘Finish partitioning and write changes to disk’ option to continue:

  • Write the changes to disks? Yes

Wait for the base install to finish. Then select a country close to you. No debian mirrors in Cyprus so I use UK:

  • Debian archive mirror country: United Kingdom
  • Debian archive mirror:
  • HTTP proxy: (none)

Wait for the APT configuration to Finish.

  • Participate in the package usage survey: no

  • Choose software to install:
    • SSH server
    • standard system utilities

Wait while software is installing

  • Install the GRUB boot loader to the master boot record.
  • Device for boot loader installation:
    • /dev/sda

Wait for the installation to finish and reboot. Remember to remove the USB during the reboot cycle.

Post install steps

During start-up you will see the ‘Please unlock md1_crypt’ prompt. Type your LUKS passphrase to unlock the disk and continue.

Update and Upgrade

Login as root:

# apt update && apt -y dist-upgrade

Install essential packages

# apt -y install vim htop multitail ntp byobu ufw unattended-upgrades downtimed

Secure ssh

You need to generate an SSH key pair on you PC, if you don’t have one (you should!):

$ ssh-keygen -b 4096

Copy the public key:

$ cat ~/.ssh/

Paste the public key at the end of the /root/.ssh/authorized_keys file in your server and try to login from your PC:

$ ssh root@

Some final adjustments on your SSH config (/etc/ssh/sshd_config). Change these values:

Port 2233
PasswordAuthentication no

Restart SSH:

# systemctl restart ssh.service

Enable the UFW firewall

We are using port 2233 for SSH so we need to allow that and enable the firewall:

# ufw allow 2233/tcp
# ufw enable

Setup bonding

Since we have two ethernet cards, we may take advantage of thr Linux bonding feature and join them as one. We will be using the Adaptive load balancing mode which provides load balancing of transmit, load balancing of receive for IPv4 and requires no configuration from the switch side.

First we need to install ifenslave:

# apt -y install ifenslave

Set up this in /etc/network/interfaces:

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

# enp2s0 is manually configured, and slave to the "bond0" bonded NIC
auto enp2s0
iface eth0 inet manual
    bond-master bond0

# enp3s01 is also manually configured, thus creating a 2-link bond.
auto enp3s0
iface eth1 inet manual
    bond-master bond0

# bond0 is the bonded NIC and can be used like any other normal NIC.
# bond0 is configured using static network information.
auto bond0
iface bond0 inet static

    # bond0 uses adaptive load balancing
    bond-mode 6
    bond-miimon 100
    bond-slaves enp2s0 enp3s0

An ifup bond0 should bring the bonded interface up. Or you can just reboot.

Setup remote-unlock with dropbear

The server will be a headless system, located in a difficult to access location. So we need a way to unlock it when a power failure occurs. The most convenient way to do this is to use a mandos server but convenience comes at a cost. A safer and easier way is to use dropbear during boot (initrd). The weak point of this solution is that the server will be basically offline until the sysadmin manually unlocks it, to boot.

First we install dropbear for initrd:

# apt -y install dropbear-initramfs

Then we set a custom ssh port for dropbear. This better be different than the custom ssh port we used earlier. Change the dropbear port to 2244 in /etc/dropbear-initramfs/config:


Add the static IP in the initramtools configuration (/etc/initramfs-tools/initramfs.conf):


Copy the authorized_keys file in /etc/dropbear-initramfs:

# cp /root/.ssh/authorized_keys /etc/dropbear-initramfs/

Regenerate the initrd file:

# update-initramfs -u

Now reboot and ssh to it to test it:

$ ssh -p 2244 root@

If your pubkeys are in place you will enter a busybox shell. Enter the crypt-unlock command, supply your unlock passphrase and the system will boot to the encrypted system.

Setup a local MTA for notifications

We will be using our main mailserver as a smarthost for mail to go through.

Install the postfix MTA and the mail utility:

# apt -y install postfix mailutils

Answer these questions:

  • General type of mail configuration: Internet with smarthost
  • System mail name:
  • SMTP relay host (blank for none):

Test it:

# echo 'Testing #1' | mail -s 'Test #1'

If you get a mail in your mailbox then everything is set. If not extra configuration may be needed on the smarthost. Contact the sysadmin of the smarthost, or check the logs if you access to it.

Setup pro-active disk monitoring

Install smartmontools:

# apt -y install smartmontools

Enable S.M.A.R.T, offline testing, attribute autosave, short and long test on all 4 devices. Add these lines in /etc/smartd.conf:

/dev/sda -a -d sat -o on -S on -s (S/../.././02|L/../../6/03) -m -M exec /usr/share/smartmontools/smartd-runner
/dev/sdb -a -d sat -o on -S on -s (S/../.././02|L/../../6/03) -m -M exec /usr/share/smartmontools/smartd-runner
/dev/sdc -a -d sat -o on -S on -s (S/../.././02|L/../../6/03) -m -M exec /usr/share/smartmontools/smartd-runner
/dev/sdd -a -d sat -o on -S on -s (S/../.././02|L/../../6/03) -m -M exec /usr/share/smartmontools/smartd-runner

Restart smartmontools:

# systemctl restart smartmontools.service

Setup Software RAID10 monitoring

We also need to setup monitoring for the software raid. Add your email address in the /etc/mdadm/mdadm.conf file:


Restart the mdmonitor service:

# systemctl restart mdmonitor.service

Setup kexec for faster reboots

Kexec is a Linux kernel mechanism that can load a fresh kernel from a running system. This results in a “reboot” without in fact rebooting the computer. The system loads a new kernel, the system appears “rebooted” but skipping the BIOS?UEFI initialization, thus resulting in faster reboots.

Install kexec-tools:

# apt -y install kexec-tools

The ‘Should kexec-tools handle reboots (sysvinit only)?’ question is related only to sysvinit systems. Since we are using systemd, it has no effect in our case.

Now if you want to reboot instead of running reboot you can run systemctl kexec. The latter command will reboot the system without going though BIOS/UEFI, POST etc and your system downtime is minimized.

And we are done! Store your server in a protected location, add a UPS for power backup and you are ready.


Ceph is a distributed open source storage solution that supports Object Storage, Block Storage and File Storage.

Other open source distributed storage systems are GlusterFS and HDFS.

In this guide, we describe how to setup a basic Ceph Cluster for Block Storage. We have 25 nodes on our setup. The masternode is a MASS Region and Rack controller. The rest of the nodes are Ubuntu 16.04 deployed through MAAS. The recommended filesystem for Ceph is XFS and this is what is used on the nodes.

This guide is based on the Quick Installation guide from the Ceph Documentation. This guide uses the ceph-deploy tool which is a relatively quick way to setup Ceph, especially for newbies. There is also the Manual Installation, deployment through Ansible and juju.



  • 1 deploy node (masternode). MAAS region and rack controler is installed plus Ansible
  • 3 monitor nodes (node01,node11,node24). Ubuntu 16.04 on XFS deployed through MAAS
  • 20 OSD nodes (node02-10,12-23).

Create an Ubuntu user on masternode

It would be of convenience to create an ubuntu user on the masternode. with passwordless sudo access:

$ sudo useradd -m -s /bin/bash ubuntu

Run visudo and give passwordless sudo access to the ubuntu user:


Generate an SSH key pair for the ubuntu user:

$ ssh-keygen -b 4096
Generating public/private rsa key pair.
Enter file in which to save the key (/home/ubuntu/.ssh/id_rsa): 
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /home/ubuntu/.ssh/id_rsa.
Your public key has been saved in /home/ubuntu/.ssh/
The key fingerprint is:
SHA256:t1zWURVk7j6wJPkA3VmbcHtAKh3EB0kyanORVbiiBkU ubuntu@masternode
The key's randomart image is:
+---[RSA 4096]----+
|       .E +**B=*=|
|        ..o==oOo+|
|       .+.o.o=.=.|
|      .. oo.o....|
|       .S..=oo.. |
|        oo += +  |
|       .  o  o o |
|                .|
|                 |

Deploy the /home/ubuntu/.ssh/ pubkey on all the nodes (append in /home/ubuntu/.ssh/authorized_keys). You could add this pubkey on the MAAS user before deploying Ubuntu 16.04 on the nodes.

Set /etc/hosts

$ for ID in {01..24}; do echo "$(dig +short node${ID}.maas @ node${ID}.maas node${ID}"; done > nodes.txt

It should look like this: node01.maas node01 node02.maas node02 node03.maas node03 node04.maas node04 node05.maas node05 node06.maas node06 node07.maas node07 node08.maas node08 node09.maas node09 node10.maas node10 node11.maas node11 node12.maas node12 node13.maas node13 node14.maas node14 node16.maas node16 node17.maas node17 node18.maas node18 node19.maas node19 node20.maas node20 node21.maas node21 node22.maas node22 node23.maas node23 node24.maas node24

Now you can append the result in /etc/hosts:

$ cat nodes.txt | sudo tee -a /etc/hosts

Ansible setup

Use this setup in /etc/ansible/hosts on masternode:





Install python on all the nodes

$ for ID in {01..24}
> do
>  ssh node${ID} "sudo apt -y install python-minimal"
> done

Ensure time synchronization of the nodes

Install the theodotos/debian-ntp role from Ansible Galaxy:

$ sudo ansible-galaxy install theodotos.debian-ntp

Create a basic playbook ntp-init.yml:

- hosts: nodes
  remote_user: ubuntu
  become: yes
     - { role: theodotos.debian-ntp, ntp.server: masternode }

Apply the playbook:

$ ansible-playbook ntp-init.yml

Verify that the monitor nodes are time synchronized:

$ ansible ceph-mon -a 'timedatectl'
node11 | SUCCESS | rc=0 >>
      Local time: Fri 2017-04-28 08:06:30 UTC
  Universal time: Fri 2017-04-28 08:06:30 UTC
        RTC time: Fri 2017-04-28 08:06:30
       Time zone: Etc/UTC (UTC, +0000)
 Network time on: yes
NTP synchronized: yes
 RTC in local TZ: no

node24 | SUCCESS | rc=0 >>
      Local time: Fri 2017-04-28 08:06:30 UTC
  Universal time: Fri 2017-04-28 08:06:30 UTC
        RTC time: Fri 2017-04-28 08:06:30
       Time zone: Etc/UTC (UTC, +0000)
 Network time on: yes
NTP synchronized: yes
 RTC in local TZ: no

node01 | SUCCESS | rc=0 >>
      Local time: Fri 2017-04-28 08:06:30 UTC
  Universal time: Fri 2017-04-28 08:06:30 UTC
        RTC time: Fri 2017-04-28 08:06:30
       Time zone: Etc/UTC (UTC, +0000)
 Network time on: yes
NTP synchronized: yes
 RTC in local TZ: no

Check also the OSD nodes:

$ ansible ceph-osd -a 'timedatectl'

Install Ceph

Install ceph-deploy

On masternode:

$ sudo apt install ceph-deploy

Create a new cluster and set the monitor nodes (must be odd numbered):

$ ceph-deploy new node01 node11 node24

Install ceph on master node and all other nodes:

$ ceph-deploy install masternode node{01..24}

Deploy the monitors and gather the keys:

$ ceph-deploy mon create-initial

Prepare the OSD nodes

Create the OSD directories

Create the OSD directories on the OSD nodes:

$ I=0;
$ for ID in {02..10} {12..14} {16..23}
> do 
>  ssh -l ubuntu node${ID} "sudo mkdir /var/local/osd${I}"
>  I=$((${I}+1))
> done;

Verify that the OSD directories are created:

$ ansible ceph-osd -a "ls /var/local" | cut -d\| -f1 | xargs -n2 | sort
node02 osd0
node03 osd1
node04 osd2
node05 osd3
node06 osd4
node07 osd5
node08 osd6
node09 osd7
node10 osd8
node12 osd9
node13 osd10
node14 osd11
node16 osd12
node17 osd13
node18 osd14
node19 osd15
node20 osd16
node21 osd17
node22 osd18
node23 osd19

Nodes 01, 11 and 24 are excluded because those are the monitor nodes.

Fix OSD permissions

Because of some bug we need to change the OSD directories owneship to ceph:ceph. Otherwise you will get this:

** ERROR: error creating empty object store in /var/local/osd0: (13) Permission denied

Change the ownership of the OSD directories on the OSD nodes:

$ I=0;
$ for ID in {02..10} {12..14} {16..23}
> do 
>   ssh -l ubuntu node${ID} "sudo chown ceph:ceph /var/local/osd${I}"
>   I=$((${I}+1))
> done;

Prepare the OSDs

$ I=0
$ for ID in {02..10} {12..14} {16..23}
> do
>   ceph-deploy --username ubuntu osd prepare node${ID}:/var/local/osd${I}
>   I=$((${I}+1))
> done

Activate the OSDs

For nodes 02 – 10:

$ I=0
> for ID in {02..10} {12..14} {16..23}
> do
>   ceph-deploy --username ubuntu osd activate node${ID}:/var/local/osd${I}
>   I=$((${I}+1))
> done

Deploy the configuration file and admin key

Now we need to deploy the configuration file and admin key to the admin node and our Ceph nodes. This will save us from having to specify the monitor address and keyring every time we execute a Ceph cli command.

$ ceph-deploy admin masternode node{01..24}

Set the keyring to be world readable:

$ sudo chmod +r /etc/ceph/ceph.client.admin.keyring

Test and verify

$ ceph health
HEALTH_WARN too few PGs per OSD (9 < min 30)
HEALTH_ERR clock skew detected on mon.node11, mon.node24; 64 pgs are stuck inactive for more than 300 seconds; 64 pgs stuck inactive; 64 pgs stuck unclean; Monitor clock skew detected 

Out newly build cluster is not healthy. We need to increase Placement Groups. The formula is the number_of_minimum_expected_PGs (30) times the number_of_OSDs (20) and rounded to the closest power of 2:

30x20=500 => pg_num=512

Increase PGs:

$ ceph osd pool set rbd pg_num 512

Now we run ceph health again:

$ ceph health
HEALTH_WARN pool rbd pg_num 512 > pgp_num 64

Still some tweaking needs to be done. We need to adjust pgp_num to 512:

$ ceph osd pool set rbd pgp_num 512

And we are there at last:

$ ceph health

Create a Ceph Block Device device

Check the available storage:

$ ceph df
    SIZE       AVAIL      RAW USED     %RAW USED 
    11151G     10858G         293G          2.63 
    NAME     ID     USED     %USED     MAX AVAIL     OBJECTS 
    rbd      0       306         0         3619G           4 

Now we need to create a RADOS Block Device (RBD) to hold our data.

$ rbd create clusterdata --size 4T --image-feature layering

Check the new block device:

$ rbd ls -l
clusterdata 4096G          2

Map the block device:

$ sudo rbd map clusterdata --name client.admin

Format the clusterdata device:

$ sudo mkfs -t ext4 /dev/rbd0

Mount the blobk device:

$ mkdir /srv/clusterdata
$ mount /dev/rbd0 /srv/clusterdata

Now we have a block device for data that is distributed among the 21 storage nodes.

Here’s is a summary of some useful monitoring and troubleshooting commands for ceph

$ ceph health
$ ceph health detail
$ ceph status (ceph -s)
$ ceph osd stat
$ ceph osd tree
$ ceph mon dump
$ ceph mon stat
$ ceph -w
$ ceph quorum_status --format json-pretty
$ ceph mon_status --format json-pretty
$ ceph df

If you run into trouble contact the awesome folks at the #ceph IRC channel, hosted on Open and Free Technology Community IRC network.

Start over

In case you messed up the procedure and you need to start over you can use the following commands:

$ ceph-deploy purge masternode node{01..24}
$ ceph-deploy purgedata masternode node{01..24}
$ ceph-deploy forgetkeys
$ for ID in {02..11} {11..23}; do ssh node${ID} "sudo rm -fr /var/local/osd*"; done
$ rm ceph.conf ceph-deploy-ceph.log .cephdeploy.conf

NOTE: this procedure will destroy your Ceph cluster along with all the data!


Using ceph-deploy maybe an easy way to get started with Ceph, but it does not provide much customization. For a more fine tuned setup you maybe better with the Manual Installation, even though there is a steeper learning curve.


Wiki.js is an elegant looking wiki based on Markdown. It supports LDAP and many more authentication mechanisms. In this guide we describe how to install Wiki.js on Ubuntu 16.04.


  • An Ubuntu 16.04 instance.

Install curl, Node.js v8.x and build-essential:

# apt -y install curl
# curl -sL | bash -
# apt -y install nodejs build-essential

Install MongoDB v3.4

# apt-key adv --keyserver hkp:// --recv 0C49F3730359A14518585931BC711F9BA15703C6
# echo "deb [ arch=amd64,arm64 ] xenial/mongodb-org/3.4 multiverse" | tee /etc/apt/sources.list.d/mongodb-org-3.4.list
# apt update
# apt -y install mongodb-org

Start MongoDB:

# systemctl start mongodb

Enable MongoDB at startup:

# systemctl enable mongodb

Install git

The version that comes with Ubuntu 16.04 fills the minimum requirements so there is no need to install it from upstream.

# apt -y install git

Install Wiki.js

# mkdir /srv/wiki.js
# cd /srv/wiki.js
# npm install wiki.js@latest

You will get this message:

> Browse to http://your-server:3000/ to configure your wiki! (Replaced your-server with the hostname or IP of your server!)
▐   ⠂    ▌ I'll wait until you're done ;)

Do as the message says. Let the wizard wait until we are done, and open another shell to work with.

Setup nginx

Install Nginx:

# apt -y install nginx

Create this VirtualHost configuration (/etc/nginx/sites-available/

server {
    listen      [::]:80 ipv6only=off;
    return      301 https://$server_name$request_uri;
server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;

    ssl_session_timeout 1d;
    ssl_session_cache shared:SSL:50m;
    ssl_session_tickets off;

    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
    ssl_prefer_server_ciphers on;

    ssl_certificate /etc/nginx/ssl/;
    ssl_certificate_key /etc/nginx/ssl/;
    ssl_trusted_certificate /etc/nginx/ssl/CA.crt;

    location / {
        proxy_set_header Host $http_host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_next_upstream error timeout http_502 http_503 http_504;

Enable the VirtualHost:

# cd /etc/nginx/sites-enabled/
# ln -s ../sites-available/
# unlink default

Restart Nginx:

# systemctl restart nginx

Configure Wiki.js

After the installation you will be asked if you wish to run the configuration wizard. Select this and continue:

Yes, run configuration wizard on port 3000 (recommended)

Now browse to and follow the installation wizard:

  • Welcome!: Start
  • System Check (if all good): Continue
  • General:
    • Site title: ExampleWiki
    • Host:
    • Port: 3000
    • Site UI Language: English
    • Public Access: Not selected
    • Press: Continue
  • Important Considerations: Continue
  • Database: mongodb://localhost:27017/wiki
  • Database Check: Continue:
  • Paths:
    • Local Data Path: ./data
    • Local Repository Path: ./repo
  • Git Repository: Skip this step
  • Git Repository Check: Continue
  • Administrator Account
    • Administrator Email:
    • Password: MySecretCombination
    • ConfirmPassword: MySecretCombination
  • Finalizing: Start

Enable Wiki.js on startup

# npm install -g pm2
# pm2 startup
# pm2 save

Setup LDAP

This is an optional step for those wishing to integrate Wiki.js in their LDAP infrastructure.


Connect to the LDAP (AD) server and get all certificates:

openssl s_client -showcerts -connect | tee ldap.log

Hit ‘Ctrl-C’ to end the command.

The certificate with the ID ‘1’ in ldap.log is the ISSUING CA certificate. Extract the CUT IST ISSUING CA certificate and save it in cut_issuing_ca.crt:


Verify the certificate with:

openssl x509 -text -in cut_issuing_ca.crt

Add the CUT ISSUING CA in the trusted chain of the system:

cp cut_issuing_ca.crt /usr/local/share/ca-certificates/

Configure LDAP for Wiki.js

Make these changes in /srv/wiki.js/config.yml:

    enabled: true
    url: 'ldap://'
    bindDn: 'cn=wiki,ou=dsa,dc=example,dc=com'
    bindCredentials: 'MyLDAPCredentials'
    searchBase: 'ou=people,dc=example,dc=com'
    searchFilter: '(uid={{username}})'
    tlsEnabled: true
    tlsCertPath: '/etc/ssl/certs/ca-certificates.crt'

Give Access permissions to authenticated users

Visit the Admin URL:

Click on ‘Users’. You will get a list of users. You can give ‘Read and Write’ access to them from the ‘Access Rights’ field and you can upgrade them to ‘Global Administrators’ from the ‘Role Override’ field.

NOTE: For LDAP the users need to login first before they are allowed to write.

Enjoy your newly created Wiki!


LXD is a relatively new technology by Canonical. It is a container hypervisor that builds on top of LXC. It shares some similarities with Docker, but LXD focuses on full blown containerized systems, instead of containerized applications.

LXD/LXC creates lighter systems than VM hypervisors, and it is an easy way to experiment with different software without messing up with your system. You can also use it in production, to run Linux systems with much greater density than on VM hypervisors. The only drawback is that the container must be the same OS as the host (Linux in this case) and it depends on the host for kernel functionality (e.g. modules etc).

In this guide we will build an LXD container with two virtual NICs which are attached to the physical NIC of it’s host using bridged networking.


  • An Ubuntu 16.04 host with two physical NICs

Prepare host networking

Install dependencies

# apt -y install bridge-utils

Setup networking on the host

There are two interfaces on the host enp3s0 and enp5s0. The first one, enp3s0 is the primary and connects to the main, DHCP enabled, internal network. The second one is connected to an isolated internal network where some critical services are running. There is no DHCP in the isolated network.

Prepare your /etc/network/interfaces configuration file like this:

# The loopback network interface 
auto lo
iface lo inet loopback

# The main Bridge
auto br0
iface br0 inet dhcp
    bridge-ifaces enp3s0
    bridge-ports enp3s0
    up ip link set enp3s0 up

# The primary network interface
iface enp3s0 inet manual

# The secondary Bridge
auto br1
iface br1 inet manual
        bridge-ifaces enp5s0
        bridge-ports enp5s0
        up ip link set enp5s0 up

# The secondary network interface
iface enp5s0 inet manual

Setup LXC/ LXD

Installation of LXD

# apt -y install lxd

Prepare a new profile

We need a profile with two NICs. First create a new profile:

# lxc profile copy default dualnic

Then edit the new profile with lxc profile edit dualnic:

  user.network_mode: link-local
description: Dual nic profile
    name: eth0
    nictype: bridged
    parent: br0
    type: nic
    name: eth1
    nictype: bridged
    parent: br1
    type: nic
name: dualnic

The names of the virtual interfaces of the container will be eth0 for the primary and eth1 for the secondary.

Launch the container

Now we want to launch a Debian jessie container, which we will retrieve from the prepared images on the

# lxc launch images:debian/jessie mycontainer -p dualnic

List the container:

# lxc list
|    NAME     |  STATE  |         IPV4         | IPV6 |    TYPE    | SNAPSHOTS |
| mycontainer | RUNNING | (eth0) |      | PERSISTENT | 0         |

The IP listed above was set by the DHCP server in the primary network.

Connect to the container:

# lxc exec mycontainer bash

Setup container’s networking

Edit /etc/network/interfaces inside our container:

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp

auto eth1
iface eth1 inet static
        up ip route add  via dev eth1
        up ip route add  via dev eth1

The routes and are internal routes that need to be reached though the secondary network.

Take a clean snapshot

Before you start working on your container, it is a good idea to get a clean snapshot, so you can revert to it, in case you mess something up.

# lxc snapshot mycontainer

If you want to learn more about the and features I urge you to read the excellent introduction to LXD 2.0 by Stéphane Graber


Rocket.Chat is a free/open source software for team collaboration. It is a full featured platform and an ideal alternative to Slack, for organizations that are dedicated to the Free Software philosophy.

In this guide we will demonstrate how you can setup Rocket.Chat for your organization.


  • A Debian stretch VM or server.
  • A FQDN pointing to the system’s IP. We will be using throughout this guide.

Installation of

Install the Snappy package manager

Snappy is not installed on Debian by default, so we need to install it:

# apt install snapd ca-certificates

Install Rocket.Chat

# snap install rocketchat-server

Check its status:

# systemctl status snap.rocketchat-server.rocketchat-server.service
● snap.rocketchat-server.rocketchat-server.service - Service for snap application rocketchat-server.rocketchat-server
   Loaded: loaded (/etc/systemd/system/snap.rocketchat-server.rocketchat-server.service; enabled; vendor preset: enabled)
   Active: active (running) since Tue 2017-01-03 12:27:50 PST; 12min ago
 Main PID: 24891 (node)
    Tasks: 10 (limit: 4915)
   CGroup: /system.slice/snap.rocketchat-server.rocketchat-server.service
           └─24891 node /snap/rocketchat-server/326/main.js

Jan 03 12:27:50 rocket systemd[1]: Started Service for snap application rocketchat-server.rocketchat-server.

Check its port (default is 3000):

# ss -lnptu | grep 3000
tcp    LISTEN     0      128       *:3000                  *:*                   users:(("node",pid=24891,fd=13))

Looks OK

Configure TLS

Install nginx

The core application does not support TLS so we will be setting up an nginx reverse proxy on top of it.

Install NGINX and certbot from Let’s Encrypt:

# apt -y install nginx python-certbot-nginx

Create the VirtualHost

We need to create this file: /etc/nginx/sites-available/

# Upstreams
upstream backend {

# HTTP Server
server {
    listen 80;

    error_log /var/log/nginx/rocketchat.access.log;

    location / {
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $http_host;

        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forward-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forward-Proto http;
        proxy_set_header X-Nginx-Proxy true;

        proxy_redirect off;

Enable the VirtualHost:

cd /etc/nginx/sites-enabled/
ln -s ../sites-available/
systemctl reload nginx

Generate the certificate

certbot --nginx run -d
  • Enter email address:
  • Agree to the ToS
  • Enforce HTTPS: Secure

The VirtualHost file (/etc/nginx/sites-available/ should look like this after the creation of the Let’s Encrypt certificate:

# Upstreams
upstream backend {

server {
    listen 80;

    error_log /var/log/nginx/rocketchat.access.log;

    location / {
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $http_host;

        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forward-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forward-Proto http;
        proxy_set_header X-Nginx-Proxy true;

        proxy_redirect off;

    listen 443 ssl; # managed by Certbot
ssl_certificate /etc/letsencrypt/live/; # managed by Certbot
ssl_certificate_key /etc/letsencrypt/live/; # managed by Certbot
ssl_session_cache shared:le_nginx_SSL:1m; # managed by Certbot
ssl_session_timeout 1440m; # managed by Certbot

ssl_protocols TLSv1 TLSv1.1 TLSv1.2; # managed by Certbot
ssl_prefer_server_ciphers on; # managed by Certbot


    if ($scheme != "https") {
        return 301 https://$host$request_uri;
    } # managed by Certbot

Now visit the website to test it: (it should redirect you to

Creating an admin account

Register a new account. You will get this warning:

WARNING: the setting site URL is configured to http://localhost and you are accessing from do you want to change to

You should ofcourse answer ‘Yes’.

This first user created is an admin user. You can set global preferences from Now users can visit the website and register with it. You may wish to Allow Notifications when you are prompted by your browser on your first visit to the site. Rocket.Chat supports many other authentication backends, including LDAP which is described in the next step.

Besides the web service you can also download native applications for Linux, Windows, Mac OS X, Android and iOS.

Configure LDAP

This is an optional step, but recommended if your organization has an LDAP or Active Directory setup. In this example we are using the Fusiondirectory setup from our previous guide.

Create a service account for, using the DSA module of Fusiondirectory:

  • Username: cn=rocketchat,ou=dsa,dc=example,dc=com
  • Password: MySecretCombination

Now go to using an admin account and set these:

  • Enable: True
  • Login Fallback: True
  • Host:
  • Port: 389
  • Encryption: StartTLS
  • CA Cert: Paste the contents of your internal ROOT CA certificate ( for example)
  • Reject Unauthorized: True
  • Domain Base: ou=people,dc=example,dc=com
  • Use Custom Domain Search: False
  • Domain Search User: cn=rocketchat,ou=dsa,example,dc=com
  • Domain Search Password: MySecretCombination
  • Domain Search User ID: uid
  • Domain Search Object Class: person
  • Domain Search Object Category: Leave Empty
  • Username Field: Leave Empty

Leave the default settings for the rest and press the SAVE CHANGES button

You can use the TEST CONNECTION button to test the connection.

You can now try to login using your LDAP username and password.


Less than a year ago I was attracted by the value for money offer of OnePlus 2 and became a proud owner. Being paranoid about Google tracking, I disabled most Google apps. Alas, some apps were impossible to disable. I assumed that this was caused by their dependencies with other core applications. Google play services was one them, but I never created an account with Google and never synced anything with them.

Time went by and it happened that data over mobile was accidentally enabled. And then I noticed from the mobile data traffic statistics, that Google Play services was creating traffic even without a Google account! Why does this happens its beyond my perception, but anyone is allowed to guess based on recent history. There is an option to disable background traffic on the stock Android ROM (OxygenOS) but that works only when data over mobile is enabled. With Wi-Fi enabled, Google Play services keeps on sending suspicious traffic, back to mother Google.

So I decided to look for alternatives to replace OxygenOS with a Google-free Android ROM. These are the options I have investigated:

  • Replicant: This seems to be the more privacy respecting Android MOD. No support for OnePlus 2, alas!
  • AOKP: This is an interesting MOD with lots of features. There are recent nightly builds for OnePlus 2. I tried to install it my Phone but gave an error when I tried to sideload it.
  • CyanogenMOD: A popular Android MOD that was recently discontinued. A fork by the name LineageOS is taking over. No image downloads yet.
    UPDATE (2-Jan-2016): There are some experimental LineageOS images here.
  • Paranoid Android: Another successful Android MOD with close ties to OnePlus. It boasts some interesting features. Officially supports all OnePlus models except the latest OnePlus 3T. I tried the OnePlus 2 image but the phone stack to the OnePlus logo boot screen.
  • Exodus: This is a minimalistic Android MOD. It is based on AOSP and is free from Google Apps. This is the only MOD I managed to get it working on my OnePlus 2.

So I decided to go with Exodus. This guide describes the procedure and preparations I followed in order to flash the latest Exodus nightly build for OnePlus 2.

DISCLAIMER: This guide could renter your device a luxurious brick! Backup everything before you continue. The author of this guide will not be liable for any damages you may cause on your device or any data lost. Proceed at your own risk!

Now we got that out of the way, let’s continue.


  • A PC. In this guide we are using Debian/Ubuntu as the PC’s Operating System but this can work with other Operating Systems, with minor adaptations.
  • An OnePlus 2 smartphone. It could possibly be used for other devices too, but I have only tested this on OnePlus 2.
  • The Android Debug Bridge (ADB). This is part of the Android SDK. On Debian/Ubuntu you can install it with apt install android-tools-adb.
  • A Type-C USB cable to connect the phone to your PC.

Make your device detectable in Linux

There is some process we need to follow so that the OnePlus 2 device is detectable by ADB

Enable Usb Debugging

To Enable USB Debugging we need to first enable the Developer Options:

  • Go into Settings
  • Dive into the About phone option
  • Tap 7 times on the Build number option
  • Go back and tap on Developer Options
  • Enable USB debugging and OEM unlock

Enable detection of device under Linux

First ensure that the device is connected:

# lsusb
 Bus 003 Device 039: ID 2a70:f003  

The device ID for OnePlus 2 is 0x2a70. Set this in ~/.android/adb_usb.ini:

# echo "0x2a70" >> ~/.android/adb_usb.ini

Download the udev rules files (Thanks Nicolas Bernaerts):

# wget --header='Accept-Encoding:none' -O /etc/udev/rules.d/51-android.rules
# chmod a+r /etc/udev/rules.d/51-android.rules
# wget --header='Accept-Encoding:none' -O /etc/udev/rules.d/69-mtp.rules
# chmod a+r /etc/udev/rules.d/69-mtp.rules

Restart the udev and ADB services:

# systemctl restart udev
# adb kill-server
# adb start-server

NOTE: make sure USB Debugging is enabled otherwise you will still not be able to see the device!

Verify that the device is present:

# adb devices 
List of devices attached 
da0afea7        unauthorized

Seems OK.

Backup your data and stock image

Since we are not using Google’s services we will need to manually backup all important data such as:

  • Export contacts on a .vcf file.
  • Save Pictures and Videos from the phone on your PC
  • Backup every other Applacation data which is important to you.

You can also backup your entire system with ADB:

# adb backup -f oneplus2.bck -apk -shared -all

This will take some time depending on the size of your data.

You can later restore your system back to normal, using this command:

# adb restore oneplus2.bck

Prepare the recovery image

Download Prepare the First Aid kit

This is a bundle that includes all the files needed to bring life to a bricked OnePlus 2 device. It includes a recovery image which we will use to install Exodus (or any other image you wish) on the device.

# wget -O ''
# unzip

All the necessary files are in the newly created, Firstaid directory.

Download TWRP Custom recovery

The recovery image that comes with Firstaid is somewhat outdated. We will download a more recent version of it and replace it in the Firstaid directory. You can download the more recent TWRP image from here. Do not use wget or other command line tools, just a normal browser to download it.

NOTE: There are more recent versions than 3.0.2-0 like 3.0.2-1 and 3.0.2-2. You can try those if you feel lucky, but be warned! Those versions did not work on my phone. You can see all the past and resent images here.

Verify the downloaded image:

# wget -O twrp-public.asc
# gpg --import twrp-public.asc
# wget
# gpg --verify twrp-3.0.2-0-oneplus2.img.asc twrp-3.0.2-0-oneplus2.img

If you get Good signature from "TeamWin <>" that means the image is correct. Now replace the TWRP image that comes with Firstaid with this one:

# cp twrp-3.0.2-0-oneplus2.img Firstaid/twrp.img

Flash the recovery image

Reboot to fastboot mode:

# adb reboot-bootloader

Alternatively you can poweroff the OnePlus 2 and press the Volume UP + Power buttons simultaneously.

Verify the presence of the device:

# fastboot devices
da0afea7               fastboot

Unlock the phone:

fastboot oem unlock

Flash Firstaid with the recent TWRP recovery image:

# cd Firstaid
# ./

Now unplug the phone from the PC, poweroff and the press the Volume DOWN + Power buttons simultaneously. This will bring your phone into TWRP recovery.

Flashing the Exodus image

Download Exodus image and verify

Download the latest Exodus image for OnePlus 2 here:

# wget
# wget 

Verify that the download is correct:

# cat ; md5sum
35dcf9ea73648682a36e673f5ed8f0eb  /android/exodus-6.0/out/target/product/oneplus2/

Seems OK

Plug the phone back to the PC and ensure that it is detectable by ADB:

# adb devices 
List of devices attached 
da0afea7        device

Flash the Exodus image

Follow these steps:

  • Wipe old data: Select Wipe and then Swipe to Factory Reset. You may need to format the system if the previous system was encrypted.
  • Enter the Sideload mode: From the TWRP start menu select Advanced then ADB Sideload and then Swipe to Start Sideload
  • From the PC’s CLI run the following command:

    # adb sideload

Wait and then reboot into the new Exodus system when done.

Optional steps

Install F-Droid:

By default Exodus has a minimal set of apps. Since we are not using Google Apps we will need to install F-Droid:

# wget
# adb install FDroid.apk

Lock your Phone

Setup a PIN or Pattern to lock the screen of your phone when not in use: Settings -> Security -> Screen Lock. Avoid fingerprint as it can be easily bypassed.

Encrypt phone

Encrypting your phone will protect your data if it gets stolen or confiscated. These are the steps Settings -> Security -> Encrypt phone. Your phone will need to be plugged to charger and charged to 80% or above, otherwise the system will refuse to start the encryption process.

Restoring the Stock OxygenOS System

If you decide that you don’t like Exodus or any other MOD that you have installed, you can restore your phone back to the stock OxygenOS. These instructions can also be used to restore your phone’s functionality after you have accidentally bricked it.

Download necessary images

Download the stock OxygenOS 3.0.2 image from here. Verify the download with:

# echo 46b1fde116275d83d05c2dd89422069f ; md5sum

Download the upgrade patch for Oxygen 3.1.0 from here. Verify the download with:

# echo 9cfa9a2a4c7fada6f9db79ea660251d0 ; md5sum 

Optionally you can download the SuperSU image if you would like your OxygenOS rooted:

# wget -O ''

Flash Recover image

First we need to restore the recovery ROM from Firstaid:

# cd Firstaid
# ./

Flash the Oxygen Images.

Before we install the OxygenOS image it is recommended to wipe the phone: From the TWRP menu select Wipe and then Swipe to factory reset. If the system was previously encrypted you will need to use TWRP to format it before the wipe.

Then we need to set the device into Sideload mode: Select Advanced -> ADB Sideload -> Swipe to Start Sideload.

First install the OxygenOS 3.0.2 image:

adb sideload

Then re-enable ADB Sideload and load the Oxygen 3.2.0 patch:

adb sideload

Optionally you can also load the SuperSU application as well

adb sideload

Finally reboot into the new system and enjoy your freshly formatted phone.


Most registrars they provide a DNS service when you purchase a domain name. But having your own DNS servers means more control to you. And if you are an aspiring sysadmin, you will find it fun and educational. We will be using BIND 9 which is, by far the most popular DNS implementation.


We will need two systems (VMs or containers) preferably on different geographic locations and different providers. One will be the master and the other system, the slave. This guide works for recent Debian or Ubuntu systems.

Some assumptions:

  • Master DNS:
    • Hostname:
    • IP:
  • Slave DNS:
    • Hostname:
    • IP:
  • Webserver:
    • Hostname: ( is an alias)
    • IP:
  • Main mailserver:
    • Hostname: ({mail,smtp,pop,imap,webmail} are aliases)
    • IP:
  • Backup mailserver:
    • Hostname:
    • IP:


Setup the /etc/hosts file

On master’s /etc/hosts: ns1

On slave’s /etc/hosts: ns2

Installing BIND

NOTE: all commands must be applied to both master and slave unless otherwise stated

apt-get -y install bind9 bind9utils

Allow port 53:

ufw allow 53

Configure the global options

Make the following changes in the /etc/bind/named.conf.options of both servers:

--- /etc/bind/named.conf.options        2016-12-12 14:44:57.163515708 -0500
+++ /etc/bind/    2016-12-12 14:52:29.749268250 -0500
@@ -1,5 +1,7 @@
 options {
        directory "/var/cache/bind";
+       recursion no;
+       allow-transfer { none; };

        // If there is a firewall between you and nameservers you want
        // to talk to, you may need to fix the firewall to allow multiple

Configure the local options

On master’s /etc/bind/named.conf.local:

--- /etc/bind/named.conf.local  2016-12-12 20:06:27.000000000 +0000
+++ /etc/bind/      2016-12-12 20:07:03.000000000 +0000
@@ -6,3 +6,8 @@
 // organization
 //include "/etc/bind/zones.rfc1918";

+zone "" {
+    type master;
+    file "/etc/bind/";
+    allow-transfer {; };

On slave’s /etc/bind/named.conf.local:

--- /etc/bind/named.conf.local  2016-11-01 13:02:24.000000000 -0400
+++ /etc/bind/      2016-12-12 15:09:47.445235343 -0500
@@ -6,3 +6,8 @@
 // organization
 //include "/etc/bind/zones.rfc1918";

+zone "" {
+    type slave;
+    file "";
+    masters {; };

Create the zone file

On master server create the zone file (/etc/bind/

$TTL 3600
@    IN    SOA (
                                            180 )

; NS Records
@       300    IN      NS    
@       300    IN      NS    

; MX Records
@       300    IN      MX      10
@       300    IN      MX      20

; Address records
@       300    IN      A     
ns1     300    IN      A     
ns2     300    IN      A     
mx1     300    IN      A     
mx1     300    IN      A     

; Alias (Canonical Name) records
www     300    IN      CNAME 
mail    300    IN      CNAME 
smtp    300    IN      CNAME 
imap    300    IN      CNAME 
pop     300    IN      CNAME 
webmail 300    IN      CNAME 

; TXT records
@       300    IN      TXT             "v=spf1 a mx ?all"

Verify the global configuration

Run the named-checkconf command on both servers. If you get any errors you should fix them before proceeding.

Verify the zone configuration

Run the following command on the master server:

named-checkzone /etc/bind/ 
zone loaded serial 2016121201

If you get ‘OK’ then your setup is correct, otherwise you should fix it before proceeding.

Restart bind and test your servers

systemctl restart bind9.service

Now test if your servers resolve your records.

The master:

dig @
;; ANSWER SECTION:   300 IN  CNAME    300 IN  A

The slave:

dig @
;; ANSWER SECTION:   300 IN  CNAME    300 IN  A

If you get any errors you can check your syslog file (/var/log/syslog).


After you have tested that everything is OK, it is time to tell your registrar about the new servers. This is called setting the glue records and you should consult the documentation of your registrar on how to do that. Ask support if you have any trouble.


In this guide we will show how you can remotely decrypt a headless Debian or Ubuntu Linux system, that has been encrypted with LUKS.


  • A LUKS encrypted Debian jessie or Ubuntu xenial system
  • Keyboard and monitor for the initial system setup
  • Allow SSH root access on the decrypted system using public key authentication
  • Use a different port for ssh (assuming port 4422) on the decrypted system

    NOTE: using a different port than the standard SSH port (22) serves a double purpose. For once, you will not received the scary WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! message every time you will try to remotely unlock the system and as an additional bonus you will get less SSH attacks on the active system.

Installing dropbear

Dropbear is a lightweight SSH server especially suitable for initial ramdisk (initrd) environments and other lightweight systems.

Install dropbear:

# apt -y install dropbear

Setup public key authentication for dropbear

Create the homedir for the root user and the SSH configuration directory:

# mkdir -p /etc/initramfs-tools/root/.ssh

Append your client SSH pubkey to authorized_keys:

# cat ~/.ssh/ | ssh -p 4422 root@encrypted-system "cat >> /etc/initramfs-tools/root/.ssh/authorized_keys"

Setup a static IP for the unlock environment

This step is optional but highly recommended if you are setting up a static, permanent service. If you skip this step DHCP will kick in, provided you have a DHCP Server in your environment.

Run this command to update the /etc/initramfs-tools/initramfs.conf configuration file:

echo IP= >> /etc/initramfs-tools/initramfs.conf

Explanation of the different fields:

NOTE: there are two successive colons (::) after the host_ip.

Setup the unlock script

Copy the following text in /etc/initramfs-tools/hooks/

# By Stinky Parkia


prereqs() {
    echo "$PREREQ"

case "$1" in
    exit 0

. "${CONFDIR}/initramfs.conf"
. /usr/share/initramfs-tools/hook-functions

if [ "${DROPBEAR}" != "n" ] && [ -r "/etc/crypttab" ] ; then
    cat > "${DESTDIR}/bin/unlock" << EOF
if PATH=/lib/unlock:/bin:/sbin /scripts/local-top/cryptroot; then
    kill \`ps | grep cryptroot | grep -v "grep" | awk '{print \$1}'\`
    # following line kill the remote shell right after the passphrase has
    # been entered.
    kill -9 \`ps | grep "\-sh" | grep -v "grep" | awk '{print \$1}'\`
    exit 0
exit 1

    chmod 755 "${DESTDIR}/bin/unlock"

    mkdir -p "${DESTDIR}/lib/unlock"
    cat > "${DESTDIR}/lib/unlock/plymouth" << EOF
[ "\$1" == "--ping" ] && exit 1
/bin/plymouth "\$@"

    chmod 755 "${DESTDIR}/lib/unlock/plymouth"

    echo To unlock root-partition run "unlock" >> ${DESTDIR}/etc/motd

Make the script executable:

# chmod +x /etc/initramfs-tools/hooks/

Apply the configuration

Apply the changes in the initial ramdisk:

# update-initramfs -u

Reboot the system:

# reboot

Remotely unlock the system

From your client, SSH into the initial ramdisk:

ssh root@encrypted-system 

If everything is correct you will be greeted by this MOTD:

To unlock root-partition run unlock

BusyBox v1.22.1 (Ubuntu 1:1.22.0-15ubuntu1) built-in shell (ash)
Enter 'help' for a list of built-in commands.

Unlock the system and boot into it:

# unlock
Please unlock disk sda3_crypt: 

You will get the following message and you will exit the remote shell if successful:

cryptsetup: sda3_crypt set up successfully
Connection to closed.

You can now login to the active Linux system using the alternative port 4422:

ssh -p 4422 root@encrypted-system

If you can login successfully to your system you can remove the keyboard and monitor and hide your system somewhere where the Sun does not shine :).

Thanks to Stinky Parkia for the excellent guide and the brilliant unlock script.


This guide is about setting up a Postfix/Dovecot system using LDAP/Fusiondirectoory as a backend.


  • Install an LDAP/Fusiondirectory infrastructure
  • A DNS A Record:       300     IN      A
  • A DNS PTR Record: 300 IN    PTR
  • A DNS MX Record (Actually more than one):    300 IN  MX  5

Install FusionDirectory Plugins

  • Install the Mail plugin:

    apt -y install fusiondirectory-plugin-mail fusiondirectory-plugin-mail-schema
    fusiondirectory-insert-schema -i /etc/ldap/schema/fusiondirectory/mail-fd.schema
    fusiondirectory-insert-schema -i /etc/ldap/schema/fusiondirectory/mail-fd-conf.schema
  • Install the Alias plugin:

    apt -y install fusiondirectory-plugin-alias fusiondirectory-plugin-alias-schema
    fusiondirectory-insert-schema -i /etc/ldap/schema/fusiondirectory/alias-fd-conf.schema
    fusiondirectory-insert-schema -i /etc/ldap/schema/fusiondirectory/alias-fd.schema
  • Install the Postfix plugin:

    apt -y install fusiondirectory-plugin-postfix fusiondirectory-plugin-postfix-schema
    fusiondirectory-insert-schema -i /etc/ldap/schema/fusiondirectory/postfix-fd.schema

Setup mail services:

  • Enter the server configuration (Systems plugin)

  • From the ‘Services’ tab create a ‘Postfix (SMTP)’ and an ‘IMAP/POP3 generic’ service

  • Add mail capability to all normal users:

    • Click the ‘Mail’ tab of a user and then press ‘Add Mail settings’

    • Fill in the ‘Primary Address. field and select as the server.
  • Add All necessary distribution lists and redirections from ‘Aliases’

Setup postfix

  • Create a service account for postfix using the ‘DSA’ plugin in *FusionDirectory’. It should look like this:

    dn: cn=postfix,ou=dsa,dc=example,dc=com
    cn: postfix
    userPassword:: yeduyt2732tet87eoiewoi32t4873t4387f7gf47gf49i6=
    structuralObjectClass: organizationalRole
    entryUUID: 280427ce-9a54-1035-8e48-bf1fd814366b
    creatorsName: cn=admin,dc=example,dc=com
    createTimestamp: 20160419082627Z
    objectClass: organizationalRole
    objectClass: top
    objectClass: simpleSecurityObject
    entryCSN: 20160419082628.006263Z#000000#000#000000
    modifiersName: cn=admin,dc=example,dc=com
    modifyTimestamp: 20160419082628Z
  • Install postfix:

    apt -y install postfix postfix-pcre postfix-ldap

    When you are prompted about “General type of mail configuration:” select “No configuration”

  • Prepare the /etc/postfix/ file:
smtpd_banner = $myhostname ESMTP $mail_name
biff = no
append_dot_mydomain = no
readme_directory = no
smtpd_tls_security_level = may
smtpd_tls_auth_only = yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtpd_tls_dh512_param_file = ${config_directory}/certs/dh_512.pem
smtpd_tls_dh1024_param_file = ${config_directory}/certs/dh_1024.pem
tls_random_source = dev:/dev/urandom
smtpd_tls_loglevel = 0
smtpd_client_new_tls_session_rate_limit = 10
smtpd_tls_exclude_ciphers =
myhostname =
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mydestination = $myhostname,, localhost.localdomain, localhost
relayhost =
mynetworks = [::ffff:]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
inet_protocols = all
local_transport = local
postscreen_greet_action = enforce
smtpd_recipient_restrictions =
    warn_if_reject reject_non_fqdn_hostname
    warn_if_reject reject_non_fqdn_sender
    check_sender_ns_access cidr:/etc/postfix/drop.cidr
    check_sender_mx_access cidr:/etc/postfix/drop.cidr
smtpd_data_restrictions = reject_multi_recipient_bounce
smtpd_sender_restrictions =
smtpd_helo_restrictions =
    check_helo_access pcre:/etc/postfix/identitycheck.pcre
disable_vrfy_command = yes
smtpd_helo_required = yes
smtpd_delay_reject = no
smtpd_client_restrictions = check_client_access cidr:/etc/postfix/drop.cidr
message_size_limit = 51200000
  • Prepare the rest of the configuration files:

    • Prepare the virtual domains file:

      cat > /etc/postfix/virtual_domains << EOF
       # Domain                Anything
    • Prepare the virtual recipients file:

      cat > /etc/postfix/ << EOF
      bind = yes
      bind_dn = cn=postfix,ou=dsa,dc=example,dc=com
      bind_pw = NotTheRealPassword
      server_host = ldap://
      search_base = ou=people,dc=example,dc=com
      domain =
      query_filter = (mail=%s)
      result_attribute = mail
      start_tls = yes
      version = 3
    • Prepare the virtual aliases file:

      cat > /etc/postfix/ << EOF
      bind = yes
      bind_dn = cn=postfix,ou=dsa,dc=example,dc=com
      bind_pw = NotTheRealPass
      server_host = ldap://
      search_base = ou=alias,dc=example,dc=com
      domain =
      query_filter = (mail=%s)
      result_attribute = gosaMailAlternateAddress, gosaMailForwardingAddress
      start_tls = yes
      version = 3
    • Prepare the identity check file:

      cat > /etc/postfix/identitycheck.pcre << EOF
      # Identity (RegEx)              Action
      /^(mail\.example\.com)$/       REJECT Hostname Abuse: $1
      /^(1\.2\.3\.4)$/                REJECT Hostname Abuse: $1
      /^(\[1\.2\.3\.4\])$/            REJECT Hostname Abuse: $1
    • Prepare the blacklist file:

      cat > /etc/postfix/drop.cidr << EOF
      # IP/CIDR                       Action
                         REJECT Blacklisted
  • Generate the virtual domains hashmap:

    postmap hash:/etc/postfix/virtual_domains
  • Start postfix:

    systemctl start postfix


    ss -lnptu | grep master
    tcp    LISTEN     0      100    *:25      *:*      users (("master",pid=15539,fd=12))
  • Enable support for smtps (port 465) and submission (port 587):

    Uncomment the following lines from /etc/postfix/

    submission inet n       -       -       -       -       smtpd
    smtps     inet  n       -       -       -       -       smtpd

    Restart postfix:

    systemctl restart postfix


    ss -lnptu | grep master
    tcp    LISTEN     0      100    *:587     *:*      users:(("master",pid=15854,fd=16))
    tcp    LISTEN     0      100    *:465     *:*      users:(("master",pid=15854,fd=19))
    tcp    LISTEN     0      100    *:25      *:*      users:(("master",pid=15854,fd=12))
  • Take precautions for perfect forward secrecy:

    mkdir /etc/postfix/certs
    cd /etc/postfix/certs
    openssl dhparam -2 -out dh_512.pem 512
    openssl dhparam -2 -out dh_1024.pem 1024
    chmod 600 dh_*
  • Lookup test:

    postmap -q ldap:/etc/postfix/
  • Open SMTP, SMTPS ans Submission ports:

    ufw allow 25/tcp
    ufw allow 465/tcp
    ufw allow 587/tcp

Install and configure dovecot

  • Create the user that will handle mail delivery:
  • Create a service account for dovecot using the ‘DSA’ plugin in *FusionDirectory’. It should look like this:

    dn: cn=dovecot,ou=dsa,dc=example,dc=com
    cn: dovecot
    userPassword:: ljsdewd98dej932j98dxjud8x3jx9843xj8943j438439e3=
    structuralObjectClass: organizationalRole
    entryUUID: 4d0d7174-9a54-1035-8e49-bf1fd814366b
    creatorsName: cn=admin,dc=example,dc=com
    createTimestamp: 20160419082730Z
    objectClass: organizationalRole
    objectClass: top
    objectClass: simpleSecurityObject
    entryCSN: 20160419082730.138012Z#000000#000#000000
    modifiersName: cn=admin,dc=example,dc=com
    modifyTimestamp: 20160419082730Z
  • Install dovecot:

    apt -y install dovecot-core dovecot-imapd dovecot-pop3d dovecot-lmtpd dovecot-ldap
  • Make the following changes in /etc/dovecot/conf.d/10-ssl.conf:

    ssl = required
    ssl_cert = </etc/ssl/certs/
    ssl_key = </etc/ssl/private/
  • Make the following changes in /etc/dovecot/conf.d/10-auth.conf:

    disable_plaintext_auth = yes
    auth_mechanisms = plain login
    !include auth-ldap.conf.ext
  • Make the following changes in /etc/dovecot/dovecot-ldap.conf.ext:

    uris = ldap://
    dn = cn=dovecot,ou=dsa,dc=example,dc=com
    dnpass = SomePass33
    tls = yes
    tls_ca_cert_file = /etc/ssl/certs/ca-certificates.crt
    tls_require_cert = demand
    ldap_version = 3
    base = ou=people,dc=example,dc=com
    user_attrs = =mail=maildir:/srv/vmail/%{ldap:mail}/Maildir
    user_filter = (&(objectClass=gosaMailAccount)(uid=%n))
    pass_attrs = uid=user,userPassword=password
    pass_filter = (&(objectClass=gosaMailAccount)(uid=%n))
    default_pass_scheme = SSHA
  • Make the following changes in /etc/dovecot/conf.d/10-logging.conf:

    log_path = syslog
    syslog_facility = mail
    auth_verbose = yes
    auth_verbose_passwords = no
    auth_debug = no
    auth_debug_passwords = no
    mail_debug = no
    verbose_ssl = no
  • Make the following changes in /etc/dovecot/conf.d/10-mail.conf:

    mail_uid = 5000
    mail_gid = 5000
  • Make the following changes in /etc/dovecot/conf.d/10-master.conf:
service imap-login {
  inet_listener imap {
    port = 143
  inet_listener imaps {
    port = 993
    ssl = yes

service pop3-login { inet_listener pop3 { port = 110 } inet_listener pop3s { port = 995 ssl = yes } }
service auth { unix_listener auth-userdb { mode = 0777 user = dovecot group = dovecot } }
  • Add the vmail user in the system:

    addgroup --system --gid 5000 vmail
    adduser --system --home /srv/vmail --uid 5000 --gid 5000 --disabled-password --disabled-login vmail
  • Restart dovecot:

    systemctl restart dovecot


    netstat -lnptu | grep dovecot
    tcp        0      0   *               LISTEN      20894/dovecot   
    tcp        0      0   *               LISTEN      20894/dovecot   
    tcp        0      0   *               LISTEN      20894/dovecot   
    tcp        0      0   *               LISTEN      20894/dovecot   
    tcp6       0      0 :::993                  :::*                    LISTEN      20894/dovecot   
    tcp6       0      0 :::995                  :::*                    LISTEN      20894/dovecot   
    tcp6       0      0 :::110                  :::*                    LISTEN      20894/dovecot   
    tcp6       0      0 :::143                  :::*                    LISTEN      20894/dovecot  
  • Check if you can login:

    openssl s_client -connect localhost:993
    <output ommitted...>
    a1 LOGIN theo MyNotSoSecretPass
    a3 LOGOUT
    * BYE Logging out
    a2 OK Logout completed.
  • Enable IMAP, IMAPS, POP3 and POP3S ports:

    ufw allow 110/tcp
    ufw allow 143/tcp
    ufw allow 993/tcp
    ufw allow 995/tcp
  • Tell postfix to deliver mail using dovecot:

    • Add the following lines at the end of /etc/postfix/

      dovecot   unix  -       n       n       -       -       pipe
        flags=ODRhu user=vmail:vmail argv=/usr/lib/dovecot/deliver -e -f ${sender} -d ${recipient}
    • Add these attributes in /etc/postfix/

      virtual_transport = dovecot
      dovecot_destination_recipient_limit = 1
  • Restart postfix and dovecot:

    systemctl restart postfix dovecot

Install SASL for SMTP AUTH

  • Create a service account for saslauthd using the ‘DSA’ plugin in *FusionDirectory’. It should look like this:

    dn: cn=saslauthd,ou=dsa,dc=example,dc=com
    cn: saslauthd
    userPassword:: ejdoedoifj9ewufd9843e9ejfd98je938jcr9843843=
    structuralObjectClass: organizationalRole
    entryUUID: 61143234-9a54-1035-8e4a-bf1fd814366b
    creatorsName: cn=admin,dc=example,dc=com
    createTimestamp: 20160419082803Z
    objectClass: organizationalRole
    objectClass: top
    objectClass: simpleSecurityObject
    entryCSN: 20160419082803.738357Z#000000#000#000000
    modifiersName: cn=admin,dc=example,dc=com
    modifyTimestamp: 20160419082803Z
  • Install SASL:

    apt -y install libsasl2-2 sasl2-bin
  • Create the /etc/postfix/sasl/smtpd.conf file:

    cat > /etc/postfix/sasl/smtpd.conf << EOF
    log_level: 3
    pwcheck_method: saslauthd
    mech_list: PLAIN LOGIN
  • Make the following changes in /etc/default/saslauthd:

    OPTIONS="-c -m /var/spool/postfix/var/run/saslauthd"
  • Create the /etc/saslauthd.conf file:

    cat > /etc/saslauthd.conf << EOF
    ldap_servers: ldap://
    ldap_bind_dn: cn=saslauthd,ou=dsa,dc=example,dc=com
    ldap_bind_pw: MySecretPass
    ldap_timeout: 10
    ldap_time_limit: 10
    ldap_scope: sub
    ldap_search_base: ou=people,dc=example,dc=com
    ldap_auth_method: bind
    ldap_filter: (&(uid=%u)(mail=*))
    ldap_debug: 0
    ldap_verbose: off
    ldap_ssl: yes
    ldap_starttls: no
    ldap_referrals: yes
  • Add the postfix user in the sasl group:

    usermod -aG sasl postfix
  • Add these attributes in /etc/postfix/

    smtpd_sasl_auth_enable = yes
    broken_sasl_auth_clients = yes
  • Restart saslauthd and postfix:

    systemctl restart saslauthd postfix
  • Test message delivery using SMTP AUTH:

    First you need to install swaks:

    apt -y install swaks

    Then use swaks to test message delivery:

    swaks --from --to --server --tls --auth plain --auth-user=theo
  • Test if the message has been delivered to inbox:

    First you need to install mutt:

    apt -y install mutt

    Then use mutt to test if the message has been delivered to inbox:

    mutt -f /srv/vmail/

    NOTE: When you are asked to create a ‘mail’ folder just say ‘no’.


LDAP/Fusiondirectory setup

In this guide we will be setting up LDAP (openldap) along with the FusionDirectory web management tool.


  • Install Debian jessie (Ubuntu 16.04 should work too) on your server or VM

  • Setup the DNS records in your DNS servers:           3599    IN      A

    NOTE: replace with you actual internal or external IP

  • Allow ssh and web services on firewall:

    apt -y install ufw
    ufw allow 22/tcp
    ufw allow 80/tcp
    ufw allow 443/tcp
    ufw enable

    NOTE: It may be a good idea to change the default ssh port from 22 to something less predictable

Setup LDAP

  • Setup in /etc/hosts: ldap
  • Install *OpenLDAP and FusionDirectory

    apt -y install slapd
    • Enter and verify the administrator password for slapd.
  • Create An Internal Certificate Authority for Example LTD:

    • First install gnutls-bin:

      apt -y install gnutls-bin
    • Create the key for the internal CA for

      certtool --generate-privkey --outfile
    • Create a certificate for our internal CA:

      certtool --generate-self-signed --load-privkey --outfile
      Generating a self signed certificate...
      Please enter the details of the certificate's distinguished name. Just press enter to ignore a field.
      Common name: Example LTD Internal ROOT CA
      Organizational unit name: IT
      Organization name: Example LTD
      Locality name: Limassol
      State or province name: Limassol
      Country name (2 chars): CY
      Enter the subject's domain component (DC): 
      This field should not be used in new certificates.
      Enter the certificate's serial number in decimal (default: 6295758616856773074): 
      The certificate will expire in (days): 7300

      Activation/Expiration time. The certificate will expire in (days): 7300

      Extensions. Does the certificate belong to an authority? (y/N): y Path length constraint (decimal, -1 for no constraint): -1 Is this a TLS web client certificate? (y/N): Will the certificate be used for IPsec IKE operations? (y/N): Is this a TLS web server certificate? (y/N): Enter a dnsName of the subject of the certificate: Enter a URI of the subject of the certificate: Enter the IP address of the subject of the certificate: Enter the e-mail of the subject of the certificate: Will the certificate be used to sign other certificates? (y/N): y Will the certificate be used to sign CRLs? (y/N): Will the certificate be used to sign code? (y/N): Will the certificate be used to sign OCSP requests? (y/N): Will the certificate be used for time stamping? (y/N): Enter the URI of the CRL distribution point: X.509 Certificate Information: Version: 3 Serial Number (hex): 575f071b0d5a41d2 Validity: Not Before: Mon Jun 13 19:19:27 UTC 2016 Not After: Sun Jun 08 19:20:00 UTC 2036 Subject: CN=Example LTD Internal ROOT CA,OU=IT,O=Example LTD,L=Limassol,ST=Limassol,C=CY, Subject Public Key Algorithm: RSA Algorithm Security Level: Medium (2048 bits) Modulus (bits 2048): 00:c0:75:c8:02:05:d0:0c:67:af:ac:0c:80:53:bf:cd a3:80:76:cf:3e:14:19:99:5c:24:b4:fc:b0:42:8d:5a 03:5d:04:a5:85:c7:fe:e3:d4:30:6c:4c:26:90:76:c5 3e:a0:dc:a7:53:a7:eb:13:60:78:44:b3:0a:b2:77:0c 46:19:96:ea:d2:46:82:9c:11:2c:a5:e2:a1:57:38:f4 8e:4d:74:4f:f9:41:dd:11:f4:c2:f5:9f:b7:9a:93:7d a7:f8:f3:dd:2e:08:6a:25:75:79:f3:63:e5:09:1f:bd 6a:38:45:85:f0:63:54:c0:08:68:41:15:66:a4:e3:84 49:7e:e5:c5:c7:6c:d3:c7:be:d5:5a:df:1a:1d:55:f8 35:73:bb:e3:ea:f7:66:af:d9:09:72:ca:17:5f:80:09 99:6a:49:e3:8b:f2:72:56:ac:f8:ba:60:49:d5:80:2a 07:e6:17:88:86:e4:3c:89:cd:af:2b:66:a1:af:53:f4 66:21:30:a3:22:af:a9:11:6e:98:e0:f7:6d:ef:8a:32 e9:0b:a4:82:7b:7b:db:2d:90:8e:bd:e4:54:04:a4:52 e8:cf:f6:2e:9b:97:46:ab:cb:38:06:23:33:db:42:0c 25:41:5a:d7:02:15:07:c6:e8:86:0b:a6:d7:7d:81:16 bd Exponent (bits 24): 01:00:01 Extensions: Basic Constraints (critical): Certificate Authority (CA): TRUE Key Purpose (not critical): Time stamping. Key Usage (critical): Certificate signing. Subject Key Identifier (not critical): 7a596f6dea4080e89c9e78a698d7126cd63dafa7 Other Information: Public Key ID: 7a596f6dea4080e89c9e78a698d7126cd63dafa7 Public key's random art: +--[ RSA 2048]----+ | | | . . | | . . . | | o . . | | . .+. S o | | =o..o. + . . | | o.o= .oo . o o | | oo+. .o o o | |o... E+ .o | +-----------------+

      Is the above information ok? (y/N): y

      Signing certificate...
    • Add the Example LTD Internal ROOT CA as trusted in ca-certificates:

      mkdir /usr/share/ca-certificates/extra
      cp /usr/share/ca-certificates/extra
      dpkg-reconfigure ca-certificates

      Add the extra/ CA as a trusted CA.

  • Configure slapd:

    dpkg-reconfigure slapd
    • Omit OpenLDAP server configuration? No
    • DNS domain name:
    • Organization name: Example LTD
    • Administrator password: ***
    • Verify password: *****
    • Database backend to use: MDB
    • Do you want the database to be removed when slapd is purged? No
    • Move old database? Yes
    • Allow LDAPv2 protocol? No
  • Configure TLS on LDAP:

    • Create a key for

      certtool --generate-privkey --outfile
      Generating a 2048 bit RSA private key...
    • Create a certificate for

      certtool --generate-certificate --load-privkey --outfile --load-ca-certificate --load-ca-privkey
      Generating a signed certificate...
      Please enter the details of the certificate's distinguished name. Just press enter to ignore a field.
      Common name:
      Organizational unit name: IT
      Organization name: Example LTD
      Locality name: Limassol
      State or province name: Limassol
      Country name (2 chars): CY
      Enter the subject's domain component (DC): 
      This field should not be used in new certificates.
      Enter the certificate's serial number in decimal (default: 6295762607454361711):

      Activation/Expiration time. The certificate will expire in (days):

      Extensions. Does the certificate belong to an authority? (y/N): Is this a TLS web client certificate? (y/N): Will the certificate be used for IPsec IKE operations? (y/N): Is this a TLS web server certificate? (y/N): Enter a dnsName of the subject of the certificate: Enter a URI of the subject of the certificate: Enter the IP address of the subject of the certificate: Enter the e-mail of the subject of the certificate: Will the certificate be used for signing (required for TLS)? (Y/n): Will the certificate be used for encryption (not required for TLS)? (Y/n): X.509 Certificate Information: Version: 3 Serial Number (hex): 575f0abc2f81186f Validity: Not Before: Mon Jun 13 19:35:45 UTC 2016 Not After: Thu Jun 11 19:36:29 UTC 2026 Subject:,OU=IT,O=Example LTD,L=Limassol,ST=Limassol,C=CY, Subject Public Key Algorithm: RSA Algorithm Security Level: Medium (2048 bits) Modulus (bits 2048): 00:d0:15:8e:02:90:5f:4a:9f:90:ea:1e:35:e6:4b:eb a9:8c:e5:bf:68:ec:83:0e:49:5b:d1:f0:08:4b:ac:b0 31:d2:e0:a7:eb:18:d3:ee:b8:38:b7:c4:0a:cc:97:cc b6:ac:2d:29:c8:a8:c4:7c:cc:f1:36:5a:e9:6b:52:f5 1e:e5:4f:90:67:34:1f:8c:a8:17:72:ee:40:87:ba:ae 8b:f8:4f:f8:be:51:ee:ea:d5:e4:17:63:79:22:41:c0 19:43:33:55:bb:46:80:5c:b8:16:18:fa:fb:17:58:c2 ed:d2:14:10:3b:57:5d:de:7f:29:ab:66:c2:81:87:05 f7:b7:27:78:a9:c0:8e:4f:1c:3f:66:6f:dd:43:26:9f 84:59:fb:c7:21:3c:62:4f:8d:4a:25:ab:7e:f0:5f:7e df:97:f7:79:f8:c7:2d:c8:5a:7a:de:ea:5b:c7:bd:e9 12:17:56:d3:47:ff:eb:fa:b5:6f:d9:56:8f:c7:e8:7a 46:92:75:cc:ff:de:0e:88:49:7d:d7:dd:6e:8d:3f:57 fa:0a:7a:3b:80:ec:0e:10:dd:70:d5:9a:8d:91:ce:72 44:06:21:d2:9d:e9:b8:91:13:68:4c:fc:e2:bb:4d:a8 97:ed:e9:a4:98:5d:e7:c0:ef:3e:9d:30:28:de:bd:10 01 Exponent (bits 24): 01:00:01 Extensions: Basic Constraints (critical): Certificate Authority (CA): FALSE Key Usage (critical): Digital signature. Key encipherment. Subject Key Identifier (not critical): 6d8a173de01efa11a892dda76ccd7abc609a2707 Authority Key Identifier (not critical): 7a596f6dea408aa89c9e78a698d7126cd63dafa7 Other Information: Public Key ID: 6d8a173de01efa00a892dda67ccd7abc609a2707 Public key's random art: +--[ RSA 2048]----+ | | | | | . | | . + | | A = | | +Y= . | | oo+kk+ | | iii==o* | | .=B**o. | +-----------------+

      Is the above information ok? (y/N): y

      Signing certificate...
    • Enable LDAPS in /etc/default/slapd:

      SLAPD_SERVICES="ldap:/// ldapi:/// ldaps:///"
    • Copy the certficate and apply permissions

      mkdir /etc/ldap/ssl
      cp /etc/ldap/ssl
      cp /etc/ldap/ssl
      chown -R openldap:openldap /etc/ldap/ssl/
    • Create a olcSSL.ldif file:

      mkdir /etc/ldap/custom_ldifs/
      cd /etc/ldap/custom_ldifs/
      cat > olcSSL.ldif << EOF dn: cn=config changetype: modify add: olcTLSCACertificateFile olcTLSCACertificateFile: /etc/ssl/certs/ca-certificates.crt - add: olcTLSCertificateKeyFile olcTLSCertificateKeyFile: /etc/ldap/ssl/ - add: olcTLSCertificateFile olcTLSCertificateFile: /etc/ldap/ssl/ EOF
    • Import the TLS configuration:

      ldapmodify -Y EXTERNAL -H ldapi:/// -f olcSSL.ldif

      Verify with:

      slapcat -n0 | grep -i tls
      olcTLSCACertificateFile: /etc/ssl/certs/ca-certificates.crt
      olcTLSCertificateFile: /etc/ldap/ssl/
      olcTLSCertificateKeyFile: /etc/ldap/ssl/
    • Restart and verify slapd:

      systemctl restart slapd
      netstat -lnptu | grep slapd
      tcp        0      0   *               LISTEN      27665/slapd     
      tcp        0      0   *               LISTEN      27665/slapd     
      tcp6       0      0 :::636                  :::*                    LISTEN      27665/slapd     
      tcp6       0      0 :::389                  :::*                    LISTEN      27665/slapd 

Setup Apache

  • Install Apache with PHP:

    apt -y install apache2 libapache2-mod-php5 php5-ldap php5-mcrypt php5-intl php-pear

Setup Let’s Encrypt:

NOTE: this step is only necessary if you have a public facing service

  • Setup Debian jessie backports:

    cat >> /etc/apt/sources.list << EOF
    # jessie backports
    deb jessie-backports main
    deb-src jessie-backports main
  • Run apt update

  • Install Let’s Encrypt utility, certbot:

    apt -y install python-certbot-apache -t jessie-backports
  • Generate a certificate for all the domain

    certbot run -d

    In the TUI add the email and agree to the ToS. Use 000-default.conf for now.

  • Download and trust all Let’s Encrypt Root and Intermediate CA certificates:

    for i in {1..4}; do wget$i-cross-signed.pem; done
    cp *.pem /usr/share/ca-certificates/extra/
    for f in *.pem; do cp -- "$f" "/usr/share/ca-certificates/extra/${f%.pem}.crt"; done
    dpkg-reconfigure ca-certificates # Select all the newlly added CA certs

Setup FusionDirectory

  • Setup Fusiondirectory Repo:

    gpg --keyserver --recv-key 62B4981F 
    gpg --export -a "Fusiondirectory Archive Manager <>" > FD-archive-key
    apt-key add FD-archive-key
    echo '# fusiondirectory repository' > /etc/apt/sources.list.d/fusiondirectory.list
    echo 'deb jessie main' >> /etc/apt/sources.list.d/fusiondirectory.list
    echo 'deb-src jessie main' >> /etc/apt/sources.list.d/fusiondirectory.list
    apt update
  • Install FusionDirectory:

    apt -y install fusiondirectory fusiondirectory-schema
  • Insert core FusionDirectory schemas into *slapd



    fusiondirectory-insert-schema -l
  • Create a Fusiondirectory Apache vhost (/etc/apache2/sites-available/

    <VirtualHost *:80>
        Redirect "/" ""
        ErrorLog ${APACHE_LOG_DIR}/ldap-error.log
        CustomLog ${APACHE_LOG_DIR}/ldap-access.log combined
    <IfModule mod_ssl.c>
        <VirtualHost *:443>
                DocumentRoot /usr/share/fusiondirectory/html
                ErrorLog ${APACHE_LOG_DIR}/ldap-error.log
                CustomLog ${APACHE_LOG_DIR}/ldap-access.log combined
                SSLEngine on
                SSLCertificateFile      /etc/letsencrypt/live/
                SSLCertificateKeyFile   /etc/letsencrypt/live/
                <FilesMatch "\.(cgi|shtml|phtml|php)$">
                                SSLOptions +StdEnvVars
                <Directory /usr/lib/cgi-bin>
                                SSLOptions +StdEnvVars
                BrowserMatch "MSIE [2-6]" \
                                nokeepalive ssl-unclean-shutdown \
                                downgrade-1.0 force-response-1.0
                BrowserMatch "MSIE [17-9]" ssl-unclean-shutdown
                <IfModule mod_php5.c>
                <Location />
                    php_admin_flag engine on
                    php_admin_flag register_globals off
                    php_admin_flag allow_call_time_pass_reference off
                    php_admin_flag expose_php off
                    php_admin_flag zend.ze1_compatibility_mode off
                    php_admin_flag register_long_arrays off
                    php_admin_value upload_tmp_dir /var/spool/fusiondirectory/
                    php_admin_value session.cookie_lifetime 0
                    #Include /etc/fusiondirectory/fusiondirectory.secrets
                <Directory /usr/share/fusiondirectory/html/>
                    Order Allow,Deny
                    # Insert your public IPs here
                    Allow from
                    Allow from
  • Enable mod_ssl, and disable 000-default and default-ssl:

    a2enmod ssl
    a2dissite default-ssl
    a2dissite 000-default
    systemctl restart apache2
  • Setup FusionDirectory:

    • Install optional prerequisities:

      apt -y install php-mdb2
    • Point your Browser to:
    • Create a temporary token for the setup (taken from the first setup webpage):

      echo -n r9l1srnu0rvdeca4k826nq4e05 > /var/cache/fusiondirectory/fusiondirectory.auth 

      Click ‘Next’

    • In the ‘Language setup’ select ‘English’ and press ‘Next’.

    • If everything is ‘OK'(Green) on the ‘Installation check’ click ‘Next’

    • On the ‘LDAP connection setup’:

      • Location name: default
      • Connection URI: ldap://
      • TLS connection: Yes
      • Admin DN: cn=admin(,dc=example,dc=com)
      • Admin password: *****
      • LDAP schema check:
        • Enable schema validation when logging in: Yes
    • Keep defaults in ‘Look and feel’ except ‘Timezone’:

      • Timezone: America/Los_Angeles
    • Keep all the defaults in ‘Password settings’ except this:

      • Password minimum length: 8
    • In the ‘SSL’ field use these:

      • Key path: /etc/ldap/ssl/
      • Certificate path: /etc/ldap/ssl/
      • CA certificate path: /etc/ssl/certs/ca-certificates.crt

      Click ‘Next’ when done.

    • In the ‘LDAP inspection’ page:

      • Press ‘Migrate’ (twice) in the ‘Inspecting object classes in root object’ option

      • Press ‘Create’ in the ‘Checking for super administrator’ option’, fill the fields, and ‘Apply’ when done:

        • User ID: ldapadmin
        • Password: ***
        • Password (again): ***
      • In the ‘Checking for default ACL roles and groups’ field, press ‘Migrate’
    • From the ‘Finish – write the configuration file’, download the configuration file on your PC

    • Copy the configuration file from your PC to

      scp fusiondirectory.conf
    • Apply the correct permissions to the /etc/fusiondirectory/fusiondirectory.conf file:

      fusiondirectory-setup --check-config
      Checking FusionDirectory's config file
      /etc/fusiondirectory/fusiondirectory.conf exists…
      /etc/fusiondirectory/fusiondirectory.conf is not set properly, do you want to fix it ?:  [Yes/No]?
    • Click ‘Next’ when done.
  • Use encrypted passwords in fusiondirectory.conf:

    • Enable the headers module in Apache:

      a2enmod headers
      systemctl restart apache2
    • Encrypt passwords in fusiondirectory.conf:

      fusiondirectory-setup --encrypt-passwords
    • Uncomment the following line in /etc/apache2/sites-available/

      Include /etc/fusiondirectory/fusiondirectory.secrets
    • Restart Apache:

      systemctl restart apache2
    • If everything works as expected remove /etc/fusiondirectory/fusiondirectory.conf.orig

      rm /etc/fusiondirectory/fusiondirectory.conf.orig
  • Allow ‘.’ (dot) in usernames:

    • After everything is set, login as ldapadmin
    • Go to ‘Configuration’
    • Press the ‘Edit’ button at the bottom of the page
    • Un-tick the ‘Strict naming policy’ option and save.

Installing essential FusionDirectory plugins

  • Setup LDAP related plugins:

    apt -y install fusiondirectory-plugin-ldapdump fusiondirectory-plugin-ldapmanager
  • Setup the DSA plugin for managing service accounts:

    apt -y install fusiondirectory-plugin-dsa fusiondirectory-plugin-dsa-schema
    fusiondirectory-insert-schema -i /etc/ldap/schema/fusiondirectory/dsa-fd-conf.schema
    • Allow the service accounts to read and write the password. First create the ACL definition:

      cat > /etc/ldap/custom_ldifs/service_accounts_acl.ldif << EOF
      dn: olcDatabase={1}mdb,cn=config
      changetype: modify
      delete: olcAccess
      add: olcAccess
      olcAccess: {0}to dn.subtree="dc=example,dc=com" attrs=userPassword
        by self write
        by dn.base="cn=admin,dc=example,dc=com" write
        by dn.children="ou=dsa,dc=example,dc=com" write
        by anonymous auth
        by * none
      add: olcAccess
      olcAccess: {1}to dn.subtree="ou=people,dc=example,dc=com"
        by self read
        by dn.base="uid=test.user,ou=people,dc=example,dc=com" write
        by dn.base="cn=admin,dc=example,dc=com" write
        by dn.children="ou=dsa,dc=example,dc=com" read
        by anonymous auth
        by * none
      add: olcAccess
      olcAccess: {2}to attrs=userPassword,shadowLastChange
        by self write
        by anonymous auth
        by dn="cn=admin,dc=example,dc=com" write
        by * none
      add: olcAccess
      olcAccess: {3}to dn.subtree="dc=example,dc=com"
        by self read
        by dn.base="cn=admin,dc=example,dc=com" write
        by dn.children="ou=dsa,dc=example,dc=com" write
        by * none
      add: olcAccess
      olcAccess: {4}to dn.base=""
        by * none

      NOTE: Add two spaces after each ‘by‘ in the ldif above or you will spend endless hours in troubleshooting!

    • Apply the ACL

      ldapadd -c -Y EXTERNAL -H ldapi:/// -f /etc/ldap/custom_ldifs/service_accounts_acl.ldif
  • Setup the Systems plugin:

    apt -y install fusiondirectory-plugin-systems fusiondirectory-plugin-systems-schema
    fusiondirectory-insert-schema -i /etc/ldap/schema/fusiondirectory/service-fd.schema
    fusiondirectory-insert-schema -i /etc/ldap/schema/fusiondirectory/systems-fd-conf.schema
    fusiondirectory-insert-schema -i /etc/ldap/schema/fusiondirectory/systems-fd.schema
    • Setup a new server:

      • Name:
      • Description: Communications Server
      • Location: My Datacenter
      • Base: /

      • IP-address:
      • MAC-address: 04:01:05:d6:63:02
    • From the ‘Services’ tab setup an LDAP service on the server

You are finished. You can now start connecting services to your LDAP setup like mail or asterisk.