[TAMAYA-372] Clarifiy/isolate metadata format

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.3-incubating
• Fix Version/s: 0.4-incubating
• Component/s: API, Core, Extensions
• Assignee: Anatole Tresch
• Reporter: Anatole Tresch
• Created: 11/Dec/18 09:58
• Updated: 06/Jan/19 23:28
• Resolved: 06/Jan/19 23:28

Description

Currently we use different metadata formats:

• like etcd: starting with an '_', e.g. _a.b.c.meta=ghfghgf
• Using a bracket stype prefix similar to log formats: [META]a.b.c.meta=ghfghgf

The proposal is to

• Add a MetaDataProvider SPI that
  • extracts metadata inline with the config entries.
  • extracts metadata from the property value metadata entries
  • supports adding metadata also programmatically

Along with that the default metadata format should be changed to:

[(META)a.b.c].meta=ghfghgf

 

This allows for future extensions of metadata types and defines a clear parseable structure for adding metadata along the configuration.