sdk/resource: Add Resource.WithoutSchemaURL

[pellared]

Fixes #2341
Fixes #3769
Fixes #4476

This should mitigate a common problem. Most users seem to want to have some "easy fix".

Pros:

• Acceptable from the OTel Specification perspective.
• Can be used in a fine grained manner. One can only set it to empty for “problematic” resource attributes. But also one could always use this for all resources being merged.

Current alternative:

• One could call resource.NewSchemaless(r.Attributes()…). However, this is clunky and it is not efficient as it copies a slice (which is not needed as attribute.Set is immutable).

Side notes:

I was also thinking of adding an option to Merge, but this would be not compliant with the specification. Also it would be hard to answer what schemaURL should be set in case of a conflict.

[codecov]

Codecov Report

Merging #4484 (dfba85b) into main (6eedabf) will increase coverage by 0.0%.
The diff coverage is 100.0%.

@@          Coverage Diff          @@
##            main   #4484   +/-   ##
=====================================
  Coverage   81.3%   81.3%           
=====================================
  Files        220     220           
  Lines      17670   17672    +2     
=====================================
+ Hits       14378   14380    +2     
  Misses      2992    2992           
  Partials     300     300           

Files Changed	Coverage
sdk/resource/resource.go	100.0%

[pellared]

CC @ash2k @pkwarren @maximkosov @dustinmoris

[MrAlias]

I would rather we provide a translation layer than remove a part of the resource that is included by the specification.

[pellared]

I would rather we provide a translation layer than remove a part of the resource that is included by the specification.

Is the translation defined in the OTel Specification?

[pellared]

SIG meeting: This API will not help a lot. Closing.

@MrAlias Will try to revive the translation layer.