Dokku is an extensible, open source Platform as a Service that runs on a single server of your choice. If you ever used Heroku, then think of it as your hosted version of Heroku. You can have docker based Platform as a Service running on a single server. In this guide, we will cover the installation of Dokku PaaS on Ubuntu 20.04|18.04 Linux System.
As of this article update the supported operating systems are:
- Ubuntu 16.04/18.04/20.04 x64
- Debian 9+ x64
With CentOS 7 still experimental
Installing Dokku on Ubuntu – Pre-requisites
- Installed and updated Ubuntu 20.04|18.04 system
- Docker Engine
- At least 1GB of system memory
- Server with FQDN set – Can be on DNS or /etc/hosts
There are two ways of installing Dokku on Ubuntu 20.0418.04:
- Using bootstrap script
- Installing from Dokku apt repository
We will consider both methods to install Dokku on Ubuntu 20.04|18.04 Linux server. I recommend installing Dokku from the apt repository so that you can have a view of what’s happening.
Set system hostname using the hostnamectl command:
$ sudo hostamectl set-hostname dokku.neveropen.co.zaEnsure your system is updated and upgraded:
sudo apt update
sudo apt upgrade -y
sudo rebootMethod 1: Install Dokku on Ubuntu 20.04|18.04 from apt repository
Dokku packages are available on packagecloud.io dokku repository. Start by importing repository GPG key to trust packages:
sudo apt update
sudo apt install -y apt-transport-https
wget -nv -O - https://packagecloud.io/dokku/dokku/gpgkey | sudo apt-key add -Key importation output:
2020-10-08 19:40:09 URL:https://d28dx6y1hfq314.cloudfront.net/505/623/gpg/dokku-dokku-FB2B6AA421CD193F.pub.gpg?t=1602179109_89e21c60fdf77e8ab2181ba23ae0dc910985dfbb [3937/3937] -> "-" [1]
OKAdd the repo using the commands below:
OS_ID="$(lsb_release -cs 2>/dev/null || echo "bionic")"
echo "deb https://packagecloud.io/dokku/dokku/ubuntu/ ${OS_ID} main" | sudo tee /etc/apt/sources.list.d/dokku.listThen update system package list:
sudo apt update
Step 1: Install Docker Engine on Ubuntu 20.04|18.04
You can install either stable release of Docker or edge release, both are supported by Dokku.
wget -nv -O - https://get.docker.com/ | sudo bash -Add your user account to docker group:
sudo usermod -aG docker $USER
newgrp dockerThis is unattended installation, wait for it to complete then confirm docker engine version installed:
$ docker version
Client: Docker Engine - Community
Version: 19.03.13
API version: 1.40
Go version: go1.13.15
Git commit: 4484c46d9d
Built: Wed Sep 16 17:02:52 2020
OS/Arch: linux/amd64
Experimental: false
Server: Docker Engine - Community
Engine:
Version: 19.03.13
API version: 1.40 (minimum version 1.12)
Go version: go1.13.15
Git commit: 4484c46d9d
Built: Wed Sep 16 17:01:20 2020
OS/Arch: linux/amd64
Experimental: false
containerd:
Version: 1.3.7
GitCommit: 8fba4e9a7d01810a393d5d25a3621dc101981175
runc:
Version: 1.0.0-rc10
GitCommit: dc9208a3303feef5b3839f4323d9beb36df0a9dd
docker-init:
Version: 0.18.0
GitCommit: fec3683
Step 2: Install Dokku on Ubuntu 20.04|18.04
Once docker has been installed, you can proceed to install Dokku on your Ubuntu 20.04|18.04 LTS system. This is done by updating system packages and installing dokku package:
sudo apt update
sudo apt install dokku -yDependencies installed through apt include:
- herokuish
- sshcommand
- plugn
When asked whether to enable web configuration interface, answer yes
Installation of dokku will also configure nginx for you and create a systemd service unit for managing the service. Installation output summary is shown below:
....
Adding user dokku to group adm
Starting nginx (via systemctl): nginx.service.
-----> Priming bash-completion cache
Ensure proper sshcommand path
Setting up dokku-installer
Enabling dokku-installer
Created symlink /etc/systemd/system/multi-user.target.wants/dokku-installer.service → /etc/systemd/system/dokku-installer.service.
Created symlink /etc/systemd/system/graphical.target.wants/dokku-installer.service → /etc/systemd/system/dokku-installer.service.
Starting dokku-installer
Processing triggers for libc-bin (2.31-0ubuntu9.1) ...
Processing triggers for ufw (0.36-6) ...
Processing triggers for systemd (245.4-4ubuntu3.2) ...
Processing triggers for man-db (2.9.1-1) ...Install dokku dependencies:
sudo dokku plugin:install-dependencies --coreA user and group named dokku is also added to the system, its home directory is /home/dokku. This user account is used when deploying applications to Dokku.
$ id dokku
uid=1001(dokku) gid=1002(dokku) groups=1002(dokku),4(adm),998(docker)
$ ls -la /home/dokku/
total 44
drwxr-xr-x 5 dokku dokku 4096 Oct 8 19:45 .
drwxr-xr-x 4 root root 4096 Oct 8 19:43 ..
drwxr-xr-x 2 dokku dokku 4096 Oct 8 19:45 .basher
-rw-r--r-- 1 dokku dokku 220 Oct 8 19:43 .bash_logout
-rw-r--r-- 1 dokku dokku 3771 Oct 8 19:43 .bashrc
-rw-r--r-- 1 dokku dokku 0 Oct 8 19:43 .cloud-locale-test.skip
drwxr-xr-x 2 dokku dokku 4096 Oct 8 19:43 .dokkurc
-rw-r--r-- 1 dokku dokku 29 Oct 8 19:43 HOSTNAME
-rw-r--r-- 1 dokku dokku 807 Oct 8 19:43 .profile
drwxr-xr-x 2 dokku dokku 4096 Oct 8 19:43 .ssh
-rw-r--r-- 1 dokku root 15 Oct 8 19:44 .sshcommand
-rw-r--r-- 1 dokku dokku 29 Oct 8 19:43 VHOSTThe service should be running by default after the installation. The name of the service is dokku-installer.service:
$ systemctl status dokku-installer.service
● dokku-installer.service - Dokku web-installer
Loaded: loaded (/etc/systemd/system/dokku-installer.service; enabled; vendor preset: enabled)
Active: active (running) since Thu 2020-10-08 19:44:41 CEST; 6min ago
Main PID: 14789 (python3)
Tasks: 1 (limit: 2286)
Memory: 8.3M
CGroup: /system.slice/dokku-installer.service
└─14789 python3 /usr/share/dokku/contrib/dokku-installer.py selfdestruct
Oct 08 19:44:41 ubuntu systemd[1]: Started Dokku web-installer.
Oct 08 19:44:41 ubuntu sudo[14817]: root : TTY=unknown ; PWD=/ ; USER=root ; COMMAND=/usr/sbin/ufw status
Oct 08 19:44:41 ubuntu sudo[14817]: pam_unix(sudo:session): session opened for user root by (uid=0)
Oct 08 19:44:41 ubuntu sudo[14817]: pam_unix(sudo:session): session closed for user rootConfirm if the service is enabled to start on boot:
$ systemctl is-enabled dokku-installer.service
enabledDokku version can be checked using:
$ dokku version
dokku version 0.21.4Step 3: Configure Dokku on Ubuntu 20.04|18.04
When done with the installation, go to your server’s IP and follow the web installer to configure Dokku.
Confirm:
SSH Public keythat you’ll use to access Dokku apps.- Provide FQDN hostname for dokku to be used for apps URL
- Check
Use virtualhost namingto have your apps deployed on Dokku with hostnames
Then click “Finish Setup” button to finish Installation of Dokku on Ubuntu 20.04|18.04.
Note that Once you save your settings, the web admin will self-terminate and you should be able to run or deploy to the Dokku installation.
Upgrading Dokku on Ubuntu 20.04|18.04
To upgrade Dokku to the latest stable release, use dokku-update command:
sudo dokku ps:stopall
sudo apt update
sudo apt install -qq -y dokku herokuish sshcommand plugn gliderlabs-sigil
sudo sudo apt upgradeUpgrading Dokku with above command will not affect the running dokku and automates many of the upgrade instructions for you. If you would like to rebuild all applications after the upgrade, use:
sudo dokku ps:rebuildallInstalling Dokku Plugins
Dokku provides a handful of Plugins to manage other functionalities. All are available on Dokku has official plugins. Installation of these plugins is done on the Dokku host as a root user or using a user account with sudo privileges.
See examples below:
Install PostgreSQL datastore service:
sudo dokku plugin:install https://github.com/dokku/dokku-postgres.gitInstall MariaDB datastore plugin:
sudo dokku plugin:install https://github.com/dokku/dokku-mariadb.git mariadbDeploying Apps to Dokku
Now that you have a working Dokku installation on your Ubuntu 20.04|18.04 system, you can begin deployment of applications. You can read a comprehensive guide on deploying apps to Dokku.
Conclusion
Dokku is a free and open-source Docker-based PaaS that allows you to basically do the same things as Heroku on your own infrastructure (on-premises or cloud). It is easy to setup and use. If you have any challenges with the installation and configuration, let me know through the comment section.