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 (xenial, 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:ubuntu16.04`
  37   - `williamyeh/ansible:ubuntu14.04`
  38   - `williamyeh/ansible:ubuntu12.04`
  39   - `williamyeh/ansible:centos7`
  40   - `williamyeh/ansible:centos6`
  41   - `williamyeh/ansible:alpine3`
  42
  43 - Onbuild series (*recommended for common cases*):
  44
  45   - `williamyeh/ansible:debian8-onbuild`
  46   - `williamyeh/ansible:debian7-onbuild`
  47   - `williamyeh/ansible:ubuntu16.04-onbuild`
  48   - `williamyeh/ansible:ubuntu14.04-onbuild`
  49   - `williamyeh/ansible:ubuntu12.04-onbuild`
  50   - `williamyeh/ansible:centos7-onbuild`
  51   - `williamyeh/ansible:centos6-onbuild`
  52   - `williamyeh/ansible:alpine3-onbuild`
  53
  54 ### Old 1.9 version:
  55
  56 - Normal series:
  57
  58   - `williamyeh/ansible:1.9-debian8`
  59   - `williamyeh/ansible:1.9-debian7`
  60   - `williamyeh/ansible:1.9-ubuntu14.04`
  61   - `williamyeh/ansible:1.9-ubuntu12.04`
  62   - `williamyeh/ansible:1.9-centos7`
  63   - `williamyeh/ansible:1.9-centos6`
  64   - `williamyeh/ansible:1.9-alpine3`
  65
  66 - Onbuild series (*recommended for common cases*):
  67
  68   - `williamyeh/ansible:1.9-debian8-onbuild`
  69   - `williamyeh/ansible:1.9-debian7-onbuild`
  70   - `williamyeh/ansible:1.9-ubuntu14.04-onbuild`
  71   - `williamyeh/ansible:1.9-ubuntu12.04-onbuild`
  72   - `williamyeh/ansible:1.9-centos7-onbuild`
  73   - `williamyeh/ansible:1.9-centos6-onbuild`
  74   - `williamyeh/ansible:1.9-alpine3-onbuild`
  75
  76 ### Experimental version (building directly from the git `master` source tree; use at your own risk!):
  77
  78 - Normal series:
  79
  80   - `williamyeh/ansible:master-debian8`
  81   - `williamyeh/ansible:master-debian7`
  82   - `williamyeh/ansible:master-ubuntu16.04`
  83   - `williamyeh/ansible:master-ubuntu14.04`
  84   - `williamyeh/ansible:master-ubuntu12.04`
  85   - `williamyeh/ansible:master-centos7`
  86   - `williamyeh/ansible:master-centos6`
  87
  88 - Onbuild series (*recommended for common cases*):
  89
  90   - `williamyeh/ansible:master-debian8-onbuild`
  91   - `williamyeh/ansible:master-debian7-onbuild`
  92   - `williamyeh/ansible:master-ubuntu16.04-onbuild`
  93   - `williamyeh/ansible:master-ubuntu14.04-onbuild`
  94   - `williamyeh/ansible:master-ubuntu12.04-onbuild`
  95   - `williamyeh/ansible:master-centos7-onbuild`
  96   - `williamyeh/ansible:master-centos6-onbuild`
  97
  98
  99
 100 ## For the impatient
 101
 102 Here comes a simplest working example for the impatient.
 103
 104 First, choose a base image you'd like to begin with. For example, `williamyeh/ansible:ubuntu14.04-onbuild`.
 105
 106 Second, put the following `Dockerfile` along with your playbook directory:
 107
 108 ```
 109 FROM williamyeh/ansible:ubuntu14.04-onbuild
 110
 111 # ==> Specify requirements filename;  default = "requirements.yml"
 112 #ENV REQUIREMENTS  requirements.yml
 113
 114 # ==> Specify playbook filename;      default = "playbook.yml"
 115 #ENV PLAYBOOK      playbook.yml
 116
 117 # ==> Specify inventory filename;     default = "/etc/ansible/hosts"
 118 #ENV INVENTORY     inventory.ini
 119
 120 # ==> Executing Ansible (with a simple wrapper)...
 121 RUN ansible-playbook-wrapper
 122 ```
 123
 124 Third, `docker build .`
 125
 126 Done!
 127
 128 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 on [CircleCI](https://circleci.com/)'s Ubuntu 12.04 and [Travis CI](https://travis-ci.org/)’s Ubuntu 14.04 worker instances.
 129
 130
 131
 132
 133 ## Why yet another Ansible image for Docker?
 134
 135 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?
 136
 137 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:
 138
 139 - *Base OS image* - It provides only `centos:centos7` and `ubuntu:14.04`.  Insufficent for me.
 140
 141 - *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.
 142
 143 Therefore, I built these Docker images on my own.
 144
 145 **NOTE:** [`ansible/ansible-docker-base`](https://github.com/ansible/ansible-docker-base) announced in September 2015: “Ansible no longer maintains images in Dockerhub directly.”
 146
 147 ### Comparison: image size
 148
 149 ```
 150 REPOSITORY                    TAG                   VIRTUAL SIZE
 151 ---------------------------   -------------------   ------------
 152 ansible/centos7-ansible       stable                367.5 MB
 153 ansible/ubuntu14.04-ansible   stable                286.6 MB
 154
 155 williamyeh/ansible            alpine3-onbuild        66.4 MB
 156 williamyeh/ansible            centos6-onbuild       264.2 MB
 157 williamyeh/ansible            centos7-onbuild       275.3 MB
 158 williamyeh/ansible            debian7-onbuild       134.4 MB
 159 williamyeh/ansible            debian8-onbuild       178.3 MB
 160 williamyeh/ansible            ubuntu12.04-onbuild   181.9 MB
 161 williamyeh/ansible            ubuntu14.04-onbuild   238.3 MB
 162 ```
 163
 164
 165 ## Usage
 166
 167 Used mostly as a *base image* for configuring other software stack on some specified Linux distribution(s).
 168
 169 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:
 170
 171 ```ruby
 172 # Vagrantfile
 173
 174 Vagrant.configure(2) do |config|
 175
 176     # ==> Choose a Vagrant box to emulate Linux distribution...
 177     #config.vm.box = "ubuntu/xenial64"
 178     config.vm.box = "ubuntu/trusty64"
 179     #config.vm.box = "ubuntu/precise64"
 180     #config.vm.box = "debian/jessie64"
 181     #config.vm.box = "debian/wheezy64"
 182     #config.vm.box = "bento/centos-7.2"
 183     #config.vm.box = "bento/centos-6.7"
 184     #config.vm.box = "maier/alpine-3.3.1-x86_64"
 185
 186
 187     # ==> Executing Ansible...
 188     config.vm.provision "ansible" do |ansible|
 189         ansible.playbook = "playbook.yml"
 190     end
 191
 192 end
 193 ```
 194
 195 Virtual machines can emulate a variety of Linux distributions with good quality, at the cost of runtime overhead.
 196
 197
 198 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:
 199
 200
 201 ```dockerfile
 202 # Dockerfile
 203
 204 # ==> Choose a base image to emulate Linux distribution...
 205 #FROM williamyeh/ansible:ubuntu16.04
 206 FROM williamyeh/ansible:ubuntu14.04
 207 #FROM williamyeh/ansible:ubuntu12.04
 208 #FROM williamyeh/ansible:debian8
 209 #FROM williamyeh/ansible:debian7
 210 #FROM williamyeh/ansible:centos7
 211 #FROM williamyeh/ansible:centos6
 212 #FROM williamyeh/ansible:alpine3
 213
 214
 215 # ==> Copying Ansible playbook...
 216 WORKDIR /tmp
 217 COPY  .  /tmp
 218
 219 # ==> Creating inventory file...
 220 RUN echo localhost > inventory
 221
 222 # ==> Executing Ansible...
 223 RUN ansible-playbook -i inventory playbook.yml \
 224       --connection=local --sudo
 225 ```
 226
 227 You may also work with `onbuild` series, which take care of many routine steps for you:
 228
 229 ```dockerfile
 230 # Dockerfile
 231
 232 # ==> Choose a base image to emulate Linux distribution...
 233 #FROM williamyeh/ansible:ubuntu16.04-onbuild
 234 FROM williamyeh/ansible:ubuntu14.04-onbuild
 235 #FROM williamyeh/ansible:ubuntu12.04-onbuild
 236 #FROM williamyeh/ansible:debian8-onbuild
 237 #FROM williamyeh/ansible:debian7-onbuild
 238 #FROM williamyeh/ansible:centos7-onbuild
 239 #FROM williamyeh/ansible:centos6-onbuild
 240 #FROM williamyeh/ansible:alpine3-onbuild
 241
 242
 243 # ==> Specify requirements filename;  default = "requirements.yml"
 244 #ENV REQUIREMENTS  requirements.yml
 245
 246 # ==> Specify playbook filename;      default = "playbook.yml"
 247 #ENV PLAYBOOK      playbook.yml
 248
 249 # ==> Specify inventory filename;     default = "/etc/ansible/hosts"
 250 #ENV INVENTORY     inventory.ini
 251
 252 # ==> Executing Ansible (with a simple wrapper)...
 253 RUN ansible-playbook-wrapper
 254 ```
 255
 256
 257
 258 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!
 259
 260 If better OS emulation (virtualization) isn't required, the Docker approach (containerization) should give you a more efficient Ansible experience.
 261
 262
 263
 264 ## License
 265
 266 Author: William Yeh <william.pjyeh@gmail.com>
 267
 268 Licensed under the Apache License V2.0. See the [LICENSE file](LICENSE) for details.