internal/elastic: rename plugin to elastic & extend arguments

[dobarx]

Renaming elasticsearch plugin to elastic and adding additional functionality:

• Extend data.elasticsearch data source parameters #113

[traut]

That's not correct -- it should be possible to use aggr field without a query / query_string.

The error should be raised if

• only_hits is true
• and aggs are set
• and there are no query/query_string

With this combo, aggs will not be in the result, while being a primary goal of the data block.

The warning should be raised if

• only_hits is true
• and aggs are set
• and there IS query/query_string

in this case, while aggs are not present in the result, there is valuable data since hits are returned

[dobarx]

Doesn't this already match this case from specs?

throw an error when:
only_hits is true, aggs attribute is set, while no query_string or query are set -- the response will contain only aggregations but they will not be returned to the data block since only_hits is true, so there will be no data to use.

Since the if condition is:

if (params.Args.GetAttr("only_hits").IsNull() || params.Args.GetAttr("only_hits").True()) &&
		!params.Args.GetAttr("aggs").IsNull() {
		if params.Args.GetAttr("query").IsNull() && params.Args.GetAttr("query_string").IsNull() {
		

Only throws this error when only_hits is true (if null we assume it's true by default), aggs is not null and both query & query_string are null.

[dobarx]

As for warning, it's added to diagnostics like this if error was not returned but only_hits is true & aggs is not null:

	diags = diags.Append(&hcl.Diagnostic{
			Severity: hcl.DiagWarning,
			Summary:  "Aggregations are not supported",
			Detail:   "Aggregations are not supported when only_hits is true",
		})

Am I missing something here?

[traut]

oh, you're right. apologies, the error message caught my eye but I didn't dig into the condition itself!