Provide capability to scrape multiple resources under on metrics, aggregated with labels per resource

We want to be able to use Prometheus labels on our metrics. We are currently using Azure Metrics Exporter. If we scrape two databases for their DTU consumption using a metric called dtu_consumption_percent_percent_average, it will label them with resource_group and sub_resource_name. This allows us to aggregate these metrics with PromQL queries.

As far as I know, Promitor currently does not allow you to re-use the same metric name or use labels. This leaves us having to add suffixes to metrics, which can’t be aggregated. e.g.:

- name: promitor_db_dtu_percent_my_database
  description: "DTUs consumed"
  resourceGroupName: my_group
  resourceType: Generic
  resourceUri: Microsoft.Sql/servers/my_server/databases/my_database
  filter: ""
  azureMetricConfiguration:
    metricName: dtu_consumption_percent
    aggregation:
      type: Average

Specification

• Allow us to define Prometheus labels in metric configurations
• Allow duplicate metric names if the label values are different

[tomkerkhove]

As things keep on getting delayed I’m introducing #646 which allows us to version metrics declaration. If this feature does not make it for v1.0 we can still easily provide this in v1.x without breaking changes.

[tomkerkhove]

I think I’ll move it out for now and can still make it more flexible later on if people really want to (although I think we shouldn’t)