Specifically this change makes it optional to:
* Specify `includes`, `excludes` and `requires`maps in the allocate action as long as at least one fo the options is specified and is not an empty map
* Specify an `after` parameter on a phase. If no `after` value is specified `TimeValue.ZERO` is used and the phase will be moved to as soon as the previous phase reports `ACTIONS COMPLETED`. `after` is always non-null when we are serialising the Phase.
* Specify a `type` for a LifecyclePolicy. If no `type` is specified `TimeSeriesLifecycleType.INSTANCE` is used since this is currently the only production `type`. `type` is always non-null when we are serialising the LifecyclePolicy.
This PR adds a new setting called `index.lifecycle.date` that
the ShrinkAction will be responsible for populating in the newly created index.
This way, we can continue to know when we should be executing the next phase
relative to the original index creation date, and not that of the shrunken index.
This does the following in sequential service polls
1. sets the index to read-only and runs shrink with a modified `index.lifecycle.name` setting set to `null`.
2. checks to see if shrink is complete, if it is...
b. set target index's `index.lifecycle.*` settings to the original index's values.
3. if not complete, just wait till next iteration
4. if operating on shrunken index, delete old index and add it as an alias to shrunken index
* Adds Allocate lifcycle action
* Addresses review comments
Still need to make a change in core for the FilterAllocationDecider to make the execute logic simpler
* Addresses more review comments
* Adds randomMap method to AllocateActionTests
* Addresses further review comments
* Improves handling of exceptions in Index Lifecycle
This change improves a few different aspects:
* If an exception occurs executing the lifecycle of one index it is caught, logged and other indexes are still processed
* If the lifecycle policy specified in the settings does not exist an error is logged
* Fixes the exception when the delete action is run which occurs because Phase attempts to update the phase and action settings for the deleted index. A `LifecycleAction.indexSurvives()` method is introduced which defaults to `true` but can be overridden to indicate whether the index survives following completion of the action.
* Adds test
This change moves the Action classes and referenced data model classes to the new :x-pack-elasticsearch:plugin:core project in preparation for splitting the x-pack features into their own gradle modules.
Note that the TransportAction classes had to be promoted to their own class file (rather than being inner classes to their Action) so they can remain in the plugin project (and will late be move to the `index-lifecycle` project when its created.
Tal Levy
Colin Goodheart-Smithe