Ecs container advanced configuration

[roleyfoley]

Description

Adds a collection of changes for ECS to allow for advanced configurations

• Support setting the hostname for a container within a task
• Exposes volume driver configuration to users to use dynamic provisioning of volumes - mainly for the rexray/ebs volume
• Support for overriding the container fragment Id when processing fragment files
• Allows for override of the docker container image to align with the ability to override the image version
• Adds support for placement constraints - Which allow you to restrict where a task is placed based on the labels assigned to either the ecs host or the task. For example attribute:ecs.availability-zone == ap-southeast-2a would only allow the task to be placed on an ec2 ecs host in ap-southeast-2a

This also adds support for docker in docker when running Jenkins agents. While not always a recommend approach this PR covers off most of the concerns outlined in http://jpetazzo.github.io/2015/09/03/do-not-use-docker-in-docker-for-ci/

Motivation and Context

These changes have primarily been focussed on introducing the features required to make docker in docker work nicely on an ECS cluster for Jenkins agent hosting

How Has This Been Tested?

Tested on codepublican testing environment

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• Refactor (non-breaking change which improves the structure or operation of the implementation)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Followup Actions

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.
• None of the above.

[ml019]

AS this is new, reckon we drop the legacy name and just support "Fragment"

[roleyfoley]

Removed

[ml019]

All looks fine