Dockerizing WordPress

1. Dockerizing WordPress

2. Requirements
• In order to complete this tutorial, you should make sure that
you have docker installed. For more information about
installation please visit the Docker website:
http://docs.docker.io/en/latest/
• You should also be familiar with the dockerfile instructions
covered in the dockerfile tutorial:
http://www.docker.io/learn/dockerfile/
• In addition to WordPress, we first need to install Apache,
MySQL and PHP inside our container. To keep this presentation
straightforward all these different software will be install in one
single docker container

3. • Throughout this tutorial I use docker with Vagrant and a
VirtualBox VM on a Mac computer. To get Docker and
WordPress running, the first step is to edit our Vagrantfile
with the line in red here below:
Computers-MacBook-Air:~ communityPC$ cd docker
Computers-MacBook-Air:docker communityPC$ emacs Vagrantfile
# Setup virtual machine box. This VM configuration code is
always executed.
config.vm.box = BOX_NAME
config.vm.box_url = BOX_URI
config.vm.forward_port 80, 8880

4. • Now that we have specified in our Vagrantfile that accessing
"localhost:8080" will access port 80 on the guest machine, we
can start the VM. We see that our change here below in red
has been taken into consideration
Computers-MacBook-Air:docker communityPC$ vagrant up
Bringing machine 'default' up with 'virtualbox' provider...
[default] Setting the name of the VM...
[default] Clearing any previously set forwarded ports...
[default] Creating shared folders metadata...
[default] Clearing any previously set network interfaces...
[default] Preparing network interfaces based on configuration...
[default] Forwarding ports...
[default] -- 22 => 2222 (adapter 1)
[default] -- 80 => 8880 (adapter 1)
[default] Booting VM...
[default] Waiting for VM to boot. This can take a few minutes.
[default] VM booted and ready for use!
[default] Mounting shared folders...
[default] -- /vagrant

5. • The following command will SSH into our running VM and give
us access to a shell
Computers-MacBook-Air:docker communityPC$ vagrant ssh
Welcome to Ubuntu 12.04 LTS (GNU/Linux 3.8.0-29-generic x86_64)
* Documentation: https://help.ubuntu.com/
Welcome to your Vagrant-built virtual machine.
Last login: Fri Sep 20 20:56:40 2013 from 10.0.2.2
• At this point it is important to become “root” to have
permission to start a container
vagrant@precise64:~$ sudo su
root@precise64:/home/vagrant#

6. • Lets create a new directory to proceed with our WordPress
installation
root@precise64:/home/vagrant# mkdir wordpress
root@precise64:/home/vagrant# cd wordpress
root@precise64:/home/vagrant/wordpress#
• We are now ready to open emacs and build our Dockerfile
root@precise64:/home/vagrant/wordpress# emacs Dockerfile

7. • So this is how our finished Dockerfile looks like. Note that the lines starting with
# are comments that give explanation about what will happen when building a
docker container from that Dockerfile
# Install LAMP stack and Wordpress
# use the latest ubuntu image
FROM ubuntu:12.04
MAINTAINER: Victor Coisne “victor.coisne@dotcloud.com"
# make sure the package repository is up to date
RUN echo "deb http://archive.ubuntu.com/ubuntu precise main universe" > /etc/apt/sources.list
RUN apt-get update
# install apache, mysql, php, emacs, wget and wordpress
RUN apt-get install -y mysql-server mysql-client
RUN apt-get install -y apache2 apache2-mpm-prefork apache2-utils apache2.2-common libapache2-mod-php5 libapr1 libaprutil1
libdbd-mysql-perl libdbi-perl libnet-daemon-perl libplrpc-perl libpq5 mysql-common php5-common php5-mysql
RUN apt-get install -y emacs23 wget
# download the lastest version of wordpress and move the sources to the default apache serveur host /var/www
RUN wget http://wordpress.org/latest.tar.gz && mv latest.tar.gz /var/www
# Setting ports to be publicly exposed when running the image (Wordpress uses ports 80)
EXPOSE 80
If you are not comfortable with the Dockerfile syntax, follow this link http://www.docker.io/learn/dockerfile/

8. • It is now time to build our container from the current directory
and use the option -t to give it a name: wordpresstuto
root@precise64:/home/vagrant/wordpress# docker build -t wordpresstuto .
• Now that we have built our container lets run it !
root@precise64:/home/vagrant/wordpress# docker run -i -t -p 80:80
wordpress_tuto /bin/bash
root@bd4b8fdbd37f:/#
• –p 80:80 tells docker to forward port 80 from the container to
the VM and connect to that VM on the same port 80. Since we
are running the host OS inside Vagrant, the Vagrantfile that we
have modified will forward that back to port 8880 on our main
system.

9. • Note that port 80 should not be already in use. You can enter the
following command to be sure that there are no other processes
listening upon port 80:
Root@precise64:/home/vagrant/wordpress# lsof -Pni4 | grep LISTEN
rpcbind 680
root 8u IPv4 948 0t0 TCP *:111 (LISTEN)
rpc.statd 726
statd 9u IPv4 8180 0t0 TCP *:48561 (LISTEN)
sshd
761
root 3u IPv4 9607 0t0 TCP *:22 (LISTEN)
memcached 930 memcache 26u IPv4 9989 0t0 TCP 127.0.0.1:11211 (LISTEN)
dnsmasq 962 lxc-dnsmasq 7u IPv4 10007 0t0 TCP 10.0.3.1:53 (LISTEN)
.
• As you can see there are no processes listening upon port 80.
If there are any, you first have to kill them if you want to run
your docker container and forward port 80 from the container
to the host.

10. • Lets now go to the directory /var/www that is the location of
the website files
root@bd4b8fdbd37f:/# cd /var/www
root@bd4b8fdbd37f:/var/www#
• Now that we are in the /var/www we can unzip the latest
version of Wordpress downloaded in our dockerfile and found
on http://codex.wordpress.org/UNIX_Shell_Skills
root@bd4b8fdbd37f:/var/www# tar zxf latest.tar.gz
• The following command allow us to edit Apache’s default
configuration file
root@bd4b8fdbd37f:/var/www# emacs /etc/apache2/sites-enabled/000-default

11. • Inside that file we just have to change the Documentroot and
Directory lines as you can see here below in red
File Edit Options Buffers Tools Help
<VirtualHost *:80>
ServerAdmin webmaster@localhost
DocumentRoot /var/www/wordpress
<Directory />
Options FollowSymLinks
AllowOverride None
</Directory>
<Directory /var/www/wordpress/>
Options Indexes FollowSymLinks MultiViews
AllowOverride None
Order allow,deny
allow from all
</Directory>

12. • MFirst let’s start the MySQL database
root@bd4b8fdbd37f:/var/www# /usr/sbin/mysqld &
• Let’s now start the Apache2 service
root@bd4b8fdbd37f:/var/www# /etc/init.d/apache2 start
• It is now time to change directory to edit the Wordpress
configuration file
root@bd4b8fdbd37f:/var/www# cd wordpress

13. • At this point, if we go to the following url in our web browser:
http://localhost:8880/ we see the following message

14. • As a result we just have to move our config-sample.php file to
a newly created wp-config.php file that Wordpress needed to
get started
root@bd4b8fdbd37f:/var/www/wordpress# mv wp-config-sample.php wpconfig.php
• Then we log in the mysql monitor as a “root” user
root@bd4b8fdbd37f:/var/www/wordpress# mysql -u root
Welcome to the MySQL monitor. Commands end with ; or g.
Your MySQL connection id is 7
Server version: 5.5.22-0ubuntu1 (Ubuntu)
Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be
trademarks of their respective owners.
Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.
mysql>

15. • Let’s start by creating the database we need to run WordPress
and give it a name
mysql> create database victor_wordpress ;
Query OK, 1 row affected (0.00 sec)
• It is now time to create a new user name and password prior to
grant permissions to that user for the specific database we have
just created. Once this is done we simply reload all the privileges
and exit the MySQL shell
mysql> CREATE USER 'newuser'@'localhost' IDENTIFIED BY 'password’ ;
mysql> GRANT ALL PRIVILEGES ON victor_wordpress.* TO 'newuser’ @'localhost’ ;
mysql> FLUSH PRIVILEGES ;
mysql> exit
Bye
• Lets now edit the configuration file using emacs
root@bd4b8fdbd37f:/var/www/wordpress# emacs wp-config.php

16. Now that we are inside the configuration file, lets edit the mysql
settings with the information previously defined in red here
below: database name, username and password
//** The name of the database for WordPress */
define('DB_NAME', 'wordpress_victor');
//** MySQL database username */
define('DB_USER', 'newuser');
//** MySQL database password */
define('DB_PASSWORD', 'password');
//** MySQL hostname */
define('DB_HOST', 'localhost');

17. • Now enter the following url in your favorite web browser: http://localhost:8880
Voilà ! You are now ready to start the Wordpress installation process.
• Wait there is one more thing to do …

18. • Don’t forget to share your work with the Docker community. To
do so we can push your container on the Docker index to store
the filesystem state and make it available for re-use.
• In order to push it on the Docker index, you first have to sign up:
https://index.docker.io/account/signup/
• So we first have to exit our container and go back to our host
root@bd4b8fdbd37f:/var/www/wordpress# exit
exit
There are stopped jobs.
root@bd4b8fdbd37f:/var/www/wordpress# exit
Exit
root@precise64:/home/vagrant/wordpress#

19. • We can use the following Docker command to find the ID of
our image (it should be the first one of the list)
root@precise64:/home/vagrant# docker ps -a
ID
IMAGE
COMMAND
bd4b8fdbd37f
wordpresstuto:latest /bin/bash
CREATED
STATUS
11 minutes ago
Exit 0
• Now that we have the ID we can commit the changes we have
made to the image and tag it using your username from the
Docker index / the name of your image. Our image is now
ready to be pushed to the docker index !
root@precise64:/home/vagrant/wordpress# docker commit bd4b8fdbd37f -t
vcoisne/wordpresstuto
93ed51f82520
root@precise64:/home/vagrant/wordpress# docker push vcoisne/wordpresstuto
• You can read more about Docker and WordPress here:
Slumlord hosting with Docker - WordPress Container

20. Want to learn more ?
http://www.docker.io/news_signup/
https://twitter.com/docker/
https://github.com/dotcloud/docker
http://stackoverflow.com/search?q=docker
https://botbot.me/freenode/docker/#
https://groups.google.com/forum/#!forum
/docker-user
https://plus.google.com/u/1/communities/
108146856671494713993
https://www.facebook.com/docker.run