README.md

   1 Docker-Ansible base images
   2 ===================
   3
   4 [![Circle CI](https://circleci.com/gh/William-Yeh/docker-ansible.svg?style=shield)](https://circleci.com/gh/William-Yeh/docker-ansible) [![Build Status](https://travis-ci.org/William-Yeh/docker-ansible.svg?branch=master)](https://travis-ci.org/William-Yeh/docker-ansible)
   5
   6
   7 ## Summary
   8
   9 Repository name in Docker Hub: **[williamyeh/ansible](https://registry.hub.docker.com/u/williamyeh/ansible/)**
  10
  11 This repository contains Dockerized [Ansible](https://github.com/ansible/ansible), published to the public [Docker Hub](https://registry.hub.docker.com/) via **automated build** mechanism.
  12
  13
  14
  15 ## Configuration
  16
  17 These are Docker images for [Ansible](https://github.com/ansible/ansible) software, installed in a selected Linux distributions.
  18
  19 - OS: Debian (jessie, wheezy), Ubuntu (trusty, precise), CentOS (7, 6), Alpine (3).
  20
  21 - Ansible: three version series -
  22
  23   1. the most recent *stable* version;
  24   2. old 1.9 version;
  25   3. the *experimental* version.
  26
  27
  28 ## Images and tags
  29
  30 ### Stable version (installed from official PyPI repo):
  31
  32 - Normal series:
  33
  34   - `williamyeh/ansible:debian8`
  35   - `williamyeh/ansible:debian7`
  36   - `williamyeh/ansible:ubuntu14.04`
  37   - `williamyeh/ansible:ubuntu12.04`
  38   - `williamyeh/ansible:centos7`
  39   - `williamyeh/ansible:centos6`
  40   - `williamyeh/ansible:alpine3`
  41
  42 - Onbuild series (*recommended for common cases*):
  43
  44   - `williamyeh/ansible:debian8-onbuild`
  45   - `williamyeh/ansible:debian7-onbuild`
  46   - `williamyeh/ansible:ubuntu14.04-onbuild`
  47   - `williamyeh/ansible:ubuntu12.04-onbuild`
  48   - `williamyeh/ansible:centos7-onbuild`
  49   - `williamyeh/ansible:centos6-onbuild`
  50   - `williamyeh/ansible:alpine3-onbuild`
  51
  52 ### Old 1.9 version:
  53
  54 - Normal series:
  55
  56   - `williamyeh/ansible:1.9-debian8`
  57   - `williamyeh/ansible:1.9-debian7`
  58   - `williamyeh/ansible:1.9-ubuntu14.04`
  59   - `williamyeh/ansible:1.9-ubuntu12.04`
  60   - `williamyeh/ansible:1.9-centos7`
  61   - `williamyeh/ansible:1.9-centos6`
  62   - `williamyeh/ansible:1.9-alpine3`
  63
  64 - Onbuild series (*recommended for common cases*):
  65
  66   - `williamyeh/ansible:1.9-debian8-onbuild`
  67   - `williamyeh/ansible:1.9-debian7-onbuild`
  68   - `williamyeh/ansible:1.9-ubuntu14.04-onbuild`
  69   - `williamyeh/ansible:1.9-ubuntu12.04-onbuild`
  70   - `williamyeh/ansible:1.9-centos7-onbuild`
  71   - `williamyeh/ansible:1.9-centos6-onbuild`
  72   - `williamyeh/ansible:1.9-alpine3-onbuild`
  73
  74 ### Experimental version (building directly from the git `master` source tree; use at your own risk!):
  75
  76 - Normal series:
  77
  78   - `williamyeh/ansible:master-debian8`
  79   - `williamyeh/ansible:master-debian7`
  80   - `williamyeh/ansible:master-ubuntu14.04`
  81   - `williamyeh/ansible:master-ubuntu12.04`
  82   - `williamyeh/ansible:master-centos7`
  83   - `williamyeh/ansible:master-centos6`
  84
  85 - Onbuild series (*recommended for common cases*):
  86
  87   - `williamyeh/ansible:master-debian8-onbuild`
  88   - `williamyeh/ansible:master-debian7-onbuild`
  89   - `williamyeh/ansible:master-ubuntu14.04-onbuild`
  90   - `williamyeh/ansible:master-ubuntu12.04-onbuild`
  91   - `williamyeh/ansible:master-centos7-onbuild`
  92   - `williamyeh/ansible:master-centos6-onbuild`
  93
  94
  95
  96 ## For the impatient
  97
  98 Here comes a simplest working example for the impatient.
  99
 100 First, choose a base image you'd like to begin with. For example, `williamyeh/ansible:ubuntu14.04-onbuild`.
 101
 102 Second, put the following `Dockerfile` along with your playbook directory:
 103
 104 ```
 105 FROM williamyeh/ansible:ubuntu14.04-onbuild
 106
 107 # ==> Specify requirements filename;  default = "requirements.yml"
 108 #ENV REQUIREMENTS  requirements.yml
 109
 110 # ==> Specify playbook filename;      default = "playbook.yml"
 111 #ENV PLAYBOOK      playbook.yml
 112
 113 # ==> Specify inventory filename;     default = "/etc/ansible/hosts"
 114 #ENV INVENTORY     inventory.ini
 115
 116 # ==> Executing Ansible (with a simple wrapper)...
 117 RUN ansible-playbook-wrapper
 118 ```
 119
 120 Third, `docker build .`
 121
 122 Done!
 123
 124 For more advanced usage, the role in Ansible Galaxy [`williamyeh/nginx`](https://galaxy.ansible.com/williamyeh/nginx/) demonstrates how to perform a simple smoke test (*configuration needs test, too!*) on a variety of (*containerized*) Linux distributions via [CircleCI](https://circleci.com/)'s Ubuntu 12.04 and [Travis CI](https://travis-ci.org/)’s Ubuntu 14.04 worker instances.
 125
 126
 127
 128
 129 ## Why yet another Ansible image for Docker?
 130
 131 There has been quite a few Ansible images for Docker (e.g., [search](https://registry.hub.docker.com/search?q=ansible) in the Docker Hub), so why reinvent the wheel?
 132
 133 In the beginning I used the [`ansible/ansible-docker-base`](https://github.com/ansible/ansible-docker-base) created by Ansible Inc. It worked well, but left some room for improvement:
 134
 135 - *Base OS image* - It provides only `centos:centos7` and `ubuntu:14.04`.  Insufficent for me.
 136
 137 - *Unnecessary dependencies* - It installed, at the very beginning of its Dockerfile, the `software-properties-common` package, which in turns installed some Python packages. I prefered to incorporate these stuff only when absolutely needed.
 138
 139 Therefore, I built these Docker images on my own.
 140
 141 **NOTE:** [`ansible/ansible-docker-base`](https://github.com/ansible/ansible-docker-base) announced in September 2015: “Ansible no longer maintains images in Dockerhub directly.”
 142
 143 ### Comparison: image size
 144
 145 ```
 146 REPOSITORY                    TAG                   VIRTUAL SIZE
 147 ---------------------------   -------------------   ------------
 148 ansible/centos7-ansible       stable                367.5 MB
 149 ansible/ubuntu14.04-ansible   stable                286.6 MB
 150
 151 williamyeh/ansible            alpine3-onbuild        66.4 MB
 152 williamyeh/ansible            centos6-onbuild       264.2 MB
 153 williamyeh/ansible            centos7-onbuild       275.3 MB
 154 williamyeh/ansible            debian7-onbuild       134.4 MB
 155 williamyeh/ansible            debian8-onbuild       178.3 MB
 156 williamyeh/ansible            ubuntu12.04-onbuild   181.9 MB
 157 williamyeh/ansible            ubuntu14.04-onbuild   238.3 MB
 158 ```
 159
 160
 161 ## Usage
 162
 163 Used mostly as a *base image* for configuring other software stack on some specified Linux distribution(s).
 164
 165 Take Debian/Ubuntu/CentOS for example. To test an Ansible `playbook.yml` against a variety of Linux distributions, we may use [Vagrant](https://www.vagrantup.com/) as follows:
 166
 167 ```ruby
 168 # Vagrantfile
 169
 170 Vagrant.configure(2) do |config|
 171
 172     # ==> Choose a Vagrant box to emulate Linux distribution...
 173     config.vm.box = "ubuntu/trusty64"
 174     #config.vm.box = "ubuntu/precise64"
 175     #config.vm.box = "debian/jessie64"
 176     #config.vm.box = "debian/wheezy64"
 177     #config.vm.box = "bento/centos-7.2"
 178     #config.vm.box = "bento/centos-6.7"
 179     #config.vm.box = "maier/alpine-3.3.1-x86_64"
 180
 181
 182     # ==> Executing Ansible...
 183     config.vm.provision "ansible" do |ansible|
 184         ansible.playbook = "playbook.yml"
 185     end
 186
 187 end
 188 ```
 189
 190 Virtual machines can emulate a variety of Linux distributions with good quality, at the cost of runtime overhead.
 191
 192
 193 Docker to be a rescue. Now, with these **williamyeh/ansible** series, we may test an Ansible `playbook.yml` against a variety of Linux distributions as follows:
 194
 195
 196 ```dockerfile
 197 # Dockerfile
 198
 199 # ==> Choose a base image to emulate Linux distribution...
 200 FROM williamyeh/ansible:ubuntu14.04
 201 #FROM williamyeh/ansible:ubuntu12.04
 202 #FROM williamyeh/ansible:debian8
 203 #FROM williamyeh/ansible:debian7
 204 #FROM williamyeh/ansible:centos7
 205 #FROM williamyeh/ansible:centos6
 206 #FROM williamyeh/ansible:alpine3
 207
 208
 209 # ==> Copying Ansible playbook...
 210 WORKDIR /tmp
 211 COPY  .  /tmp
 212
 213 # ==> Creating inventory file...
 214 RUN echo localhost > inventory
 215
 216 # ==> Executing Ansible...
 217 RUN ansible-playbook -i inventory playbook.yml \
 218       --connection=local --sudo
 219 ```
 220
 221 You may also work with `onbuild` series, which take care of many routine steps for you:
 222
 223 ```dockerfile
 224 # Dockerfile
 225
 226 # ==> Choose a base image to emulate Linux distribution...
 227 FROM williamyeh/ansible:ubuntu14.04-onbuild
 228 #FROM williamyeh/ansible:ubuntu12.04-onbuild
 229 #FROM williamyeh/ansible:debian8-onbuild
 230 #FROM williamyeh/ansible:debian7-onbuild
 231 #FROM williamyeh/ansible:centos7-onbuild
 232 #FROM williamyeh/ansible:centos6-onbuild
 233 #FROM williamyeh/ansible:alpine3-onbuild
 234
 235
 236 # ==> Specify requirements filename;  default = "requirements.yml"
 237 #ENV REQUIREMENTS  requirements.yml
 238
 239 # ==> Specify playbook filename;      default = "playbook.yml"
 240 #ENV PLAYBOOK      playbook.yml
 241
 242 # ==> Specify inventory filename;     default = "/etc/ansible/hosts"
 243 #ENV INVENTORY     inventory.ini
 244
 245 # ==> Executing Ansible (with a simple wrapper)...
 246 RUN ansible-playbook-wrapper
 247 ```
 248
 249
 250
 251 With Docker, we can test any Ansible playbook against any version of any Linux distribution without the help of Vagrant. More lightweight, and more portable across IaaS, PaaS, and even CaaS (Container as a Service) providers!
 252
 253 If better OS emulation (virtualization) isn't required, the Docker approach (containerization) should give you a more efficient Ansible experience.
 254
 255
 256
 257 ## License
 258
 259 Author: William Yeh <william.pjyeh@gmail.com>
 260
 261 Licensed under the Apache License V2.0. See the [LICENSE file](LICENSE) for details.