Support composable templates

[gingerwizard]

7.8 introduced composable and component templates. The unique api endpoints mean this is work.

We may want to separate these into different operations given the unique endpoints. A user would therefore index a set of component templates, followed by their composable templates.

Alternatively, we could extend the current create-template action to accept a mode where it first inserts the declared component_templates and then composable_templates that have been declared in the track. This would be a non breaking change as the mode would default to legacy which would cause the current behaviour.

@dliappis @danielmitterdorfer happy to take but please advise

[danielmitterdorfer]

Thanks for raising this. I tend to the first option of dedicated runner(s) as I don't think Rally should abstract the Elasticsearch APIs much.

[dliappis]

Also 👍 on dedicated runners; these should be first class citizens in Rally.

[gingerwizard]

@danielmitterdorfer @dliappis the current template implementation uses the deprecated API. I'm not sure if the intention is to remove this in 8.0. For now, i propose we make these additions.

Do we want these to be first class definitions in the track? i.e. component_templates and index_templates (composable). The former need to be inserted before the latter i believe so a runner could consume both definitions and ensure this occurs.

Alternatively, we could require a single definition e.g. index_templates under which the user defines both composable and component templates. The runner could then either inspect the body to determine the appropriate API or use a type field defined in the track definition for each template e.g.

"index_templates": [
    {
        "name": "my-default-index-template",
        "index-pattern": "my-index-*",
        "template": "default-template.json",
        "type": "component"
    }
]

The benefit of declaring these as first class citizens is that we can use the definitions in other runners should we need them e.g. for validation.

[gingerwizard]

Closed by #1099