Ansible Module for Docker

This module allows you to use Ansible to provision and de-provision Linux containers using the docker container engine.

Installation

1. Install docker

2. Install docker-py on the docker server, and/or on the host you will be running ansible playbooks from if you would like to use the docker remote API instead of ansible's SSH session.

   git clone https://github.com/dotcloud/docker-py.git
   cd docker-py
   sudo python setup.py install 
   

   NB: In order to use the docker remote API you will need to use local_action in your playbooks and set the docker_url argument to http://${inventory_hostname}.

3. Copy docker-ansible.py to your ansible module directory as docker (e.g. /usr/local/share/ansbile/docker)

   curl https://raw.github.com/cove/docker-ansible/master/docker-ansible.py > docker
   sudo mv docker /usr/local/share/ansible
   

Demo

http://ascii.io/a/3348

Usage Examples

The module will try to determine which containers it has already started on subsequent runs of the playbook.

Start one docker container running tomcat in each host of the web group and bind tomcat's listening port to 8080 on the host:

- name: start tomcat
  hosts: web
  user: root
  tasks:
  - name: run tomcat servers
    action: docker image=cove/tomcat7 command=/start-tomcat.sh ports=:8080

The tomcat server's port is NAT'ed to a dynamic port on the host, but you can determine which port the server was mapped to using $DockerContainers:

- name: start tomcat 
  hosts: web
  user: root
  tasks:
  - name: run tomcat servers
    action: docker image=cove/tomcat7 command=/start-tomcat.sh ports=8080 count=5
  - name: Display IP address and port mappings for containers
    action: shell echo Mapped to ${inventory_hostname}:${item.NetworkSettings.PortMapping.8080}
    with_items: $DockerContainers

Just as in the previous example, but iterates through the list of docker containers with a sequence:

- name: start tomcat
  hosts: web
  user: root
  vars:
  	start_containers_count: 5
  tasks:
  - name: run tomcat servers
    action: docker image=cove/tomcat7 command=/start-tomcat.sh ports=8080 count=$start_containers_count
  - name: Display IP address and port mappings for containers
    local_action: shell echo Mapped to ${inventory_hostname}:${DockerContainers[${item}].NetworkSettings.PortMapping.8080}
    with_sequence: start=0 end=$start_containers_count

Stop and remove all of the running tomcat containers:

- name: stop tomcat
  hosts: web
  user: root
  tasks:
  - name: run tomcat servers
    action: docker image=cove/tomcat7 command=/start-tomcat.sh state=absent

Parameters

parameter	required	default	choices	comments
username	no			Set remote API username
memory_limit	no	256MB		Set RAM allocated to container
env	no			Set environment variables
image	yes			Set container image to use
volumes	no			Set volume(s) to mount on the container
detach	no	True		Enable detached mode on start up, leaves container running in background
memory_swap	no			Set virtual memory swap space allocated to container
count	no	1		Set number of containers to run
password	no			Set remote API password
hostname	no			Set container hostname
docker_url	no	http://127.0.0.1:4243		URL of docker host to issue commands to
state	no	present	present stop absent kill restart	Set the state of the container
command	yes			Set command to run in a container on startup
dns	no			Set custom DNS servers for the container
volumes_from	no			Set shared volume(s) from another container
ports	yes			Set private to public port mapping specification (e.g. ports=22,80 or ports=:8080 maps 8080 directly to host)