Docker Platform Cookbook

Description

Docker is an open-source project that automates
the deployment of applications inside software containers, by providing
an additional layer of abstraction and automation of operating-system-level
virtualisation on Linux.
Docker uses the resource isolation features of the Linux kernel such as cgroups
and kernel namespaces, and a union-capable file system such as aufs and others
to allow independent "containers" to run within a single Linux instance,
avoiding the overhead of starting and maintaining virtual machines.

This cookbook provides recipes to install and configure Docker with
configuration stored in attributes. It wraps docker cookbook resources to
control Docker status and also provides resources to manager swarm cluster
creation and volumes deployment.

Requirements

Cookbooks and gems

Declared in [metadata.rb](metadata.rb) and in [Gemfile](Gemfile).

Platforms

• RHEL Family 7, tested on Centos

Note: by composing it with apt-docker cookbook, it should work fine on
Debian / Ubuntu.

Usage

Test

This cookbook is fully tested in test-kitchen, using the vagrant driver and
serverspec verifier.

For more information, see [.kitchen.yml](.kitchen.yml) and [test](test)
directory.

Attributes

Configuration is done by overriding default attributes. All configuration keys
have a default defined in [attributes/default.rb](attributes/default.rb).
Please read it to have a comprehensive view of what and how you can configure
this cookbook behavior.

In addition, you can use attributes to define docker cookbook resources.
All you have to do is to define an attribute of the same name as the resource
you want to call containing the different instances of this resource. For
instance:

"docker_volume": {
  "data": {
    "action": "create"
  },
  "to_remove": {
    "action": "remove"
  }
}

It creates a docker volume named data and remove the one called to_remove.
The key of each sub hash table is the name attribute and the value is an hash
table containing the resource configuration, mapping exactly the attribute name
defined in docker cookbook documentation.

If you need multiple arguments for an attribute, you have to declare them in
an array. If you need an array as single argument, add an extra array.

For instance:

"docker_container": {
  "my_alpine": {
    "container_name": "alpine",
    "repo": "alpine",
    "volumes": [["data:/data"]],
    "action": "run",
    "subscribes": ["redeploy", "docker_image[alpine]", "immediately"]
  }
}

You can find other examples in [.kitchen.yml](.kitchen.yml) file.

Recipes

default

Include repository, package, service and docker recipes.

repository

Configure and install official docker yum repository.

package

Install docker-engine package or upgrade it if attribute version is set to
latest.

service

Enable and start docker service. Restart it if systemd config was updated.

docker

Wrap all docker cookbook resources so it is possible to use them with
attributes. Read attributes section for more details.

swarm

Use cluster-search cookbook to determine which node should create
and initialize the swarm.

Use docker_platform_swarm resource of the cookbook to initialize or join
a swarm. See [.kitchen.yml](.kitchen.yml) for examples.

Use docker_platform_service resource of the cookbook to create a service
on a swarm manager.

The swarm will be initialized on predefined node using the
cluster-search cookbook.
The node id returned by cluster-search should be equal to the
node['docker-platform']['initiator_id'] attribute.

The swarm join token is set in a consul backend after swarm initialization.

You need a consul cluster. This is not in the scope of this cookbook but
if you need one, you should consider using Consul Platform.

Use cluster-search cookbook to determine consul cluster addresses.
The join token will be requested by nodes before joining the swarm.

Resources/Providers

swarm

For instance:

Initialize a swarm and store token on consul:

"docker_platform": {
  "swarm": {
    "consul": {
      "hosts": "consul-swarm-host"
    },
    "options": {
      "listen_addr": "0.0.0.0:2377",
      "action": "create"
    }
  }
}

Join an existing docker swarm with token stored on consul:

"docker_platform": {
  "swarm": {
    "consul": {
      "hosts": "consul-swarm-host"
    },
    "action": ["join"]
  }
}

Deploy 5 replicas of redis image on a docker swarm:

"docker_platform": {
  "services": {
    "redis": {
      "action": "create",
      "replicas": 5,
      "image": "redis:latest"
    }
  }
}

Changelog

Available in [CHANGELOG.md](CHANGELOG.md).

Contributing

Please read carefully [CONTRIBUTING.md](CONTRIBUTING.md) before making a merge
request.

License and Author

• Author:: Samuel Bernard (samuel.bernard@s4m.io)
• Author:: Florian Philippon (florian.philippon@s4m.io)

Copyright (c) 2016-2017 Sam4Mobile

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.