Prometheus Service Discovery Configuration Interception

[Aneurysm9]

To enable the OTel Operator to perform Prometheus scrape target identification for a set of Collector instances in support of #6 we need to be able to identify and extract all *_sd_config and relabel_config entries in each scrape_config entry in the Prometheus receiver configuration. All *_sd_config entries should be replaced by a single file_sd_config entry referencing a file that can be updated by the Collector Prometheus receiver's target update mechanism (to be constructed) prior to the configuration being used to create a ConfigMap for Collector instances. The extracted configurations should be preserved for use by the target discovery and distribution mechanism to be built in the Operator.

This issue should be used to track the design of the SD configuration interception mechanism in the OTel Operator and to aggregate any other issues or PRs created during implementation.

[alolita]

This is a change that needs to be made in the Operator after #33 is completed.

[alolita]

PR open-telemetry/opentelemetry-operator#389 in the Operator repo is in review currently.

[alolita]

@Aneurysm9 is there anything else that needs to be done. The previous PRs have been merged.

[Aneurysm9]

This has been completed with the Operator's target allocation capability.