Ansible Image

Ansible Docker Image

Getting Started

We considered the official ansible docker image does not work as expected and there are no official images based on the alpine docker image. So we opted to create our docker image.

You can build this docker image locally by following the instructions:

Prerequisites

As you can guess, you need to have docker and git installed on your computer. Once installed we can proceed to download the code and build the image.

Building

If you've ever built a docker image, this is nothing special.

git clone https://github.com/intelygenz/ansible-image.git && cd ansible-image
docker build --build-arg ANSIBLE_VERSION=2.5.0 -t ansible-image:local .

Once the image is built, we will have in our premises an image whose name will be: ansible-image:local.

Takes note that to build the ansible docker image the version of ansible to be built is passed to it as a building argument.

Running the tests

We can test run an Ansible dummy command to verify that the image has been successfully constructed.

docker run --rm ansible-image:local ansible --version
ansible 2.5.0
  config file = None
  configured module search path = ['/root/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/local/lib/python3.6/site-packages/ansible
  executable location = /usr/local/bin/ansible
  python version = 3.6.4 (default, Jan 10 2018, 05:26:33) [GCC 5.3.0]

Usage

Provide a valid ansible.cfg file is necessary in order to use the docker image. All files needed must be included in a volume ounted at the /ansible directory inside the container.

Invocation examples

Given the following ansible.cfg:

[defaults]

inventory = hosts
remote_user = user
host_key_checking = True

[ssh_connection]

ssh_args = "-o StrictHostKeyChecking=yes -o UserKnownHostsFile=./path/to/known_hosts"

This file sets host key checking to true and indicates a path to a valida known_hosts file.

Execute Ansible:

$ docker run --rm -v $PWD:/ansible ansible:2.7.5 ansible -m setup <my_host>

The example above assumes that all ansible config, inventory and ssh needed files exist in the current working dir ($PWD), wich will be mounted inside the container at /ansible mount point.

Notice that provide a valid known_hosts file is mandatory in order to use ansible option -k, --ask-pass because sshpass is uncompatible with manual host key checking when host_key_checking is set to True.

The use of -it options are necessary when a ssh key passphrase is asked.

$ docker run -it --rm -v $PWD:/ansible ansible-image:2.7.5 ansible -m setup <my_host>

Another example. This time with no host key checking:

[defaults]

inventory = hosts
remote_user = user
host_key_checking = False
ask_pass = True

Execute Ansible:

docker run -it --rm -v $PWD:/ansible ansible-image:2.7.5 ansible -m setup <my_host>

You can also specify Ansible options through command line.

docker run -it --rm -v $PWD:/ansible ansible-image:2.7.5 ansible -i hosts -u user -m setup -k <my_host>

Executing Ansible paybooks

Like the examples above, all Ansible config files, ssh needed files and playbook structure files must be mounted inside the container at /ansible mount point. So, given the following directory structure:

- ansible.cfg
- hosts
- playbook.yml
- roles
  - role1
  - role2
  - roleN
- ssh
  - known_hosts
  - id_rsa

And given the following ansible.cfg

[defaults]

inventory = hosts
remote_user = user
host_key_checking = True
private_key_file = ssh/id_rsa
roles_path = roles

[ssh_connection]

ssh_args = "-o StrictHostKeyChecking=yes -o UserKnownHostsFile=./ssh/known_hosts"

Execute ansible-playbook:

$ docker run -v $PWD:/ansible ansible-image:2.7.5 ansible-playbook playbook.yml

alpiquero/ansible-image