This document introduces some first steps for setting up a new development workflow using Docker containers, including pulling a Debian image, running a container interactively, building a custom Dockerfile, running linked containers for a web app and database, and accessing the database from the web container.

1. First steps to a new development workflow
Guilhem Marty (@le_pixel)
1001pharmacies.com
@1001pharmaDev

2. Virtual Machines

4. OS
Host Machine
Hypervisor
Guest OS Guest OS Guest OS Guest OS
App 1 App 2 App 2’ App 3
DB DB AMPQ
Bins/Libs Bins/Libs Bins/LibsBins/Libs

7. LXC

8. OS
Host Machine
Docker
App 1 App 2 App 2’ App 3
Bins/Libs Bins/LibsBins/Libs

9. [Yem@home]-[/var/www] $ docker pull debian:wheezy
[Yem@home]-[/var/www] $ docker run -i -t debian:wheezy /bin/bash
root@e3cfb271ab6e:/#
Run a container
[Yem@home]-[/var/www] $ docker images
REPOSITORY TAG IMAGE ID CREATED VIRTUAL
SIZE
debian wheezy 1265e16d0c28 2 days ago 84.98 MB

10. FROM debian:wheezy
Dockerfile
ENV DEBIAN_FRONTEND noninteractive
RUN apt-get update
&& apt-get install -y
apache2
php5
mysql-client
EXPOSE 80
CMD ./usr/sbin/apache2ctl -D FOREGROUND

11. Build & Run
[Yem@home]-[/var/www] $ docker build -t app ./
[Yem@home]-[/var/www] $ docker images
REPOSITORY TAG IMAGE ID CREATED VIRTUAL
SIZE
app latest 98a0cc8f6e58 6 seconds ago 169.9 MB
debian wheezy 1265e16d0c28 2 days ago 84.98 MB
[Yem@home]-[/var/www] $ docker run -d -P app
2c7082ee3b572d0743c0f09ecbab8a27a9a6ab70d354f901dc781feb1c835d21
[Yem@home]-[/var/www] $ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS
PORTS NAMES
9330f7f0947d app:latest "./usr/sbin/apache2c 15 minutes ago Up 15
minutes 0.0.0.0:49153->3306/tcp clever_feynman

14. [Yem@home]-[/var/www] $ docker run -d -P
--name app-db
-e "MYSQL_ROOT_PASSWORD=root"
mariadb:10
Run a database

15. [Yem@home]-[/var/www] $ docker run -d -P
--name app-db
-e "MYSQL_ROOT_PASSWORD=root"
mariadb:10
Link containers 1/2
[Yem@home]-[/var/www] $ docker run -d -P
--name app-web
--link app-db:db
app
/bin/bash

16. Link containers 2/2
root@55d016720713:/# cat /etc/hosts
172.17.0.4 55d016720713
127.0.0.1 localhost
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
172.17.0.2 db
root@55d016720713:/# mysql -u root -proot -h db -e "SHOW DATABASES;"
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
+--------------------+

18. Questions ?