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: four series -
  22
  23   1. the most recent *stable* version;
  24   2. old 1.9 version;
  25   3. the *experimental* version;
  26   4. for building *minimal* images from playbooks; i.e., the Ansible body will be removed when mission completed.
  27
  28
  29 ## Images and tags
  30
  31 ### Stable version (installed from official PyPI repo):
  32
  33 - Normal series:
  34
  35   - `williamyeh/ansible:debian8`
  36   - `williamyeh/ansible:debian7`
  37   - `williamyeh/ansible:ubuntu16.04`
  38   - `williamyeh/ansible:ubuntu14.04`
  39   - `williamyeh/ansible:ubuntu12.04`
  40   - `williamyeh/ansible:centos7`
  41   - `williamyeh/ansible:centos6`
  42   - `williamyeh/ansible:alpine3`
  43
  44 - Onbuild series (*recommended for common cases*):
  45
  46   - `williamyeh/ansible:debian8-onbuild`
  47   - `williamyeh/ansible:debian7-onbuild`
  48   - `williamyeh/ansible:ubuntu16.04-onbuild`
  49   - `williamyeh/ansible:ubuntu14.04-onbuild`
  50   - `williamyeh/ansible:ubuntu12.04-onbuild`
  51   - `williamyeh/ansible:centos7-onbuild`
  52   - `williamyeh/ansible:centos6-onbuild`
  53   - `williamyeh/ansible:alpine3-onbuild`
  54
  55 ### Old 1.9 version:
  56
  57 - Normal series:
  58
  59   - `williamyeh/ansible:1.9-debian8`
  60   - `williamyeh/ansible:1.9-debian7`
  61   - `williamyeh/ansible:1.9-ubuntu14.04`
  62   - `williamyeh/ansible:1.9-ubuntu12.04`
  63   - `williamyeh/ansible:1.9-centos7`
  64   - `williamyeh/ansible:1.9-centos6`
  65   - `williamyeh/ansible:1.9-alpine3`
  66
  67 - Onbuild series (*recommended for common cases*):
  68
  69   - `williamyeh/ansible:1.9-debian8-onbuild`
  70   - `williamyeh/ansible:1.9-debian7-onbuild`
  71   - `williamyeh/ansible:1.9-ubuntu14.04-onbuild`
  72   - `williamyeh/ansible:1.9-ubuntu12.04-onbuild`
  73   - `williamyeh/ansible:1.9-centos7-onbuild`
  74   - `williamyeh/ansible:1.9-centos6-onbuild`
  75   - `williamyeh/ansible:1.9-alpine3-onbuild`
  76
  77 ### Experimental version (building directly from the git `master` source tree; use at your own risk!):
  78
  79 - Normal series:
  80
  81   - `williamyeh/ansible:master-debian8`
  82   - `williamyeh/ansible:master-debian7`
  83   - `williamyeh/ansible:master-ubuntu16.04`
  84   - `williamyeh/ansible:master-ubuntu14.04`
  85   - `williamyeh/ansible:master-ubuntu12.04`
  86   - `williamyeh/ansible:master-centos7`
  87   - `williamyeh/ansible:master-centos6`
  88
  89 - Onbuild series (*recommended for common cases*):
  90
  91   - `williamyeh/ansible:master-debian8-onbuild`
  92   - `williamyeh/ansible:master-debian7-onbuild`
  93   - `williamyeh/ansible:master-ubuntu16.04-onbuild`
  94   - `williamyeh/ansible:master-ubuntu14.04-onbuild`
  95   - `williamyeh/ansible:master-ubuntu12.04-onbuild`
  96   - `williamyeh/ansible:master-centos7-onbuild`
  97   - `williamyeh/ansible:master-centos6-onbuild`
  98
  99
 100 ### Minimal series (the Ansible body will be removed when mission completed):
 101
 102 - Onbuild series:
 103
 104   - `williamyeh/ansible:mini-alpine3`
 105   - `williamyeh/ansible:mini-debian8`
 106
 107
 108
 109 ## For the impatient
 110
 111 Here comes a simplest working example for the impatient.
 112
 113 First, choose a base image you'd like to begin with. For example, `williamyeh/ansible:ubuntu14.04-onbuild`.
 114
 115 Second, put the following `Dockerfile` along with your playbook directory:
 116
 117 ```
 118 FROM williamyeh/ansible:ubuntu14.04-onbuild
 119
 120 # ==> Specify requirements filename;  default = "requirements.yml"
 121 #ENV REQUIREMENTS  requirements.yml
 122
 123 # ==> Specify playbook filename;      default = "playbook.yml"
 124 #ENV PLAYBOOK      playbook.yml
 125
 126 # ==> Specify inventory filename;     default = "/etc/ansible/hosts"
 127 #ENV INVENTORY     inventory.ini
 128
 129 # ==> Executing Ansible (with a simple wrapper)...
 130 RUN ansible-playbook-wrapper
 131 ```
 132
 133 Third, `docker build .`
 134
 135 Done!
 136
 137 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.
 138
 139
 140
 141
 142 ## Why yet another Ansible image for Docker?
 143
 144 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?
 145
 146 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:
 147
 148 - *Base OS image* - It provides only `centos:centos7` and `ubuntu:14.04`.  Insufficent for me.
 149
 150 - *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.
 151
 152 Therefore, I built these Docker images on my own.
 153
 154 **NOTE:** [`ansible/ansible-docker-base`](https://github.com/ansible/ansible-docker-base) announced in September 2015: “Ansible no longer maintains images in Dockerhub directly.”
 155
 156 ### Comparison: image size
 157
 158 ```
 159 REPOSITORY                    TAG                   VIRTUAL SIZE
 160 ---------------------------   -------------------   ------------
 161 ansible/centos7-ansible       stable                367.5 MB
 162 ansible/ubuntu14.04-ansible   stable                286.6 MB
 163
 164 williamyeh/ansible            alpine3-onbuild        66.4 MB
 165 williamyeh/ansible            centos6-onbuild       264.2 MB
 166 williamyeh/ansible            centos7-onbuild       275.3 MB
 167 williamyeh/ansible            debian7-onbuild       134.4 MB
 168 williamyeh/ansible            debian8-onbuild       178.3 MB
 169 williamyeh/ansible            ubuntu12.04-onbuild   181.9 MB
 170 williamyeh/ansible            ubuntu14.04-onbuild   238.3 MB
 171 ```
 172
 173
 174 ## Usage
 175
 176 Used mostly as a *base image* for configuring other software stack on some specified Linux distribution(s).
 177
 178 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:
 179
 180 ```ruby
 181 # Vagrantfile
 182
 183 Vagrant.configure(2) do |config|
 184
 185     # ==> Choose a Vagrant box to emulate Linux distribution...
 186     #config.vm.box = "ubuntu/xenial64"
 187     config.vm.box = "ubuntu/trusty64"
 188     #config.vm.box = "ubuntu/precise64"
 189     #config.vm.box = "debian/jessie64"
 190     #config.vm.box = "debian/wheezy64"
 191     #config.vm.box = "bento/centos-7.2"
 192     #config.vm.box = "bento/centos-6.7"
 193     #config.vm.box = "maier/alpine-3.3.1-x86_64"
 194
 195
 196     # ==> Executing Ansible...
 197     config.vm.provision "ansible" do |ansible|
 198         ansible.playbook = "playbook.yml"
 199     end
 200
 201 end
 202 ```
 203
 204 Virtual machines can emulate a variety of Linux distributions with good quality, at the cost of runtime overhead.
 205
 206
 207 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:
 208
 209
 210 ```dockerfile
 211 # Dockerfile
 212
 213 # ==> Choose a base image to emulate Linux distribution...
 214 #FROM williamyeh/ansible:ubuntu16.04
 215 FROM williamyeh/ansible:ubuntu14.04
 216 #FROM williamyeh/ansible:ubuntu12.04
 217 #FROM williamyeh/ansible:debian8
 218 #FROM williamyeh/ansible:debian7
 219 #FROM williamyeh/ansible:centos7
 220 #FROM williamyeh/ansible:centos6
 221 #FROM williamyeh/ansible:alpine3
 222
 223
 224 # ==> Copying Ansible playbook...
 225 WORKDIR /tmp
 226 COPY  .  /tmp
 227
 228 # ==> Creating inventory file...
 229 RUN echo localhost > inventory
 230
 231 # ==> Executing Ansible...
 232 RUN ansible-playbook -i inventory playbook.yml \
 233       --connection=local --sudo
 234 ```
 235
 236 You may also work with `onbuild` series, which take care of many routine steps for you:
 237
 238 ```dockerfile
 239 # Dockerfile
 240
 241 # ==> Choose a base image to emulate Linux distribution...
 242 #FROM williamyeh/ansible:ubuntu16.04-onbuild
 243 FROM williamyeh/ansible:ubuntu14.04-onbuild
 244 #FROM williamyeh/ansible:ubuntu12.04-onbuild
 245 #FROM williamyeh/ansible:debian8-onbuild
 246 #FROM williamyeh/ansible:debian7-onbuild
 247 #FROM williamyeh/ansible:centos7-onbuild
 248 #FROM williamyeh/ansible:centos6-onbuild
 249 #FROM williamyeh/ansible:alpine3-onbuild
 250
 251
 252 # ==> Specify requirements filename;  default = "requirements.yml"
 253 #ENV REQUIREMENTS  requirements.yml
 254
 255 # ==> Specify playbook filename;      default = "playbook.yml"
 256 #ENV PLAYBOOK      playbook.yml
 257
 258 # ==> Specify inventory filename;     default = "/etc/ansible/hosts"
 259 #ENV INVENTORY     inventory.ini
 260
 261 # ==> Executing Ansible (with a simple wrapper)...
 262 RUN ansible-playbook-wrapper
 263 ```
 264
 265
 266
 267 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!
 268
 269 If better OS emulation (virtualization) isn't required, the Docker approach (containerization) should give you a more efficient Ansible experience.
 270
 271
 272
 273 ## License
 274
 275 Author: William Yeh <william.pjyeh@gmail.com>
 276
 277 Licensed under the Apache License V2.0. See the [LICENSE file](LICENSE) for details.