This PR addresses several issues:
1. MetadataFormatter base class takes a pointer to a function to access specific type of metadata. All other methods operating on internals of metadata structure are moved to base class. This simplified adding new types of metadata.
2. new type of access_log METADATA tag is introduced to handle all types of metadata. It is implemented as formatter extension. It handles existing tags DYNAMIC_METADATA and CLUSTER_METADATA, so two ways of accessing dynamic and cluster metadata are allowed now. Maybe we should obsolete DYNAMIC_METADATA and CLUSTER_METADATA in the future?
3. Adds handler for ROUTE metadata. See issue #3006.
Follow up to #16121
Risk Level: Low
Testing: Unit tests.
Docs Changes: Yes.
Release Notes: Yes.
Platform Specific Features: No
Signed-off-by: Christoph Pakulski <christoph@tetrate.io>
Mirrored from https://github.com/envoyproxy/envoy @ 43b597e719230c8266998394301c5d0b3c862688
data-plane-api(Azure Pipelines)