Option to not add _total suffix to counter metrics in Prometheus exporter

[Bassardes]

Fixes #
Design discussion issue #

Changes

According to this doc

If the metric name for monotonic Sum metric points does not end in a suffix of _total a suffix of _total MUST be added by default, otherwise the name MUST remain unchanged. Exporters SHOULD provide a configuration option to disable the addition of _total suffixes.

This PR adds option to disable addition of _total suffix for counter metrics in Prometheus exporter

Merge requirement checklist

• CONTRIBUTING guidelines followed (license requirements, nullable enabled, static analysis, etc.)
• Unit tests added/updated
• Appropriate CHANGELOG.md files updated for non-trivial changes
• Changes in public API reviewed (if applicable)

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: Bassardes / name: Atrokhov Sergey (1df6fcb, f0431f5, 3f910f1, 5154a68, 12ca206, 3b1db0b, 54e16e7)
• ✅ login: utpilla / name: Utkarsh Umesan Pillai (f4d044c, d793d2e)

[codecov]

Codecov Report

Attention: 2 lines in your changes are missing coverage. Please review.

Comparison is base (6250307) 83.38% compared to head (d793d2e) 83.10%.
Report is 87 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5305      +/-   ##
==========================================
- Coverage   83.38%   83.10%   -0.28%     
==========================================
  Files         297      276      -21     
  Lines       12531    12011     -520     
==========================================
- Hits        10449     9982     -467     
+ Misses       2082     2029      -53     

Flag	Coverage Δ
unittests	?
unittests-Solution-Experimental	83.08% <86.66%> (?)
unittests-Solution-Stable	83.08% <86.66%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
...tpListener/Internal/PrometheusCollectionManager.cs	77.77% <100.00%> (ø)
...etheus.HttpListener/Internal/PrometheusExporter.cs	100.00% <100.00%> (ø)
...HttpListener/Internal/PrometheusExporterOptions.cs	100.00% <100.00%> (ø)
...ometheus.HttpListener/Internal/PrometheusMetric.cs	71.75% <100.00%> (ø)
...theusHttpListenerMeterProviderBuilderExtensions.cs	81.25% <100.00%> (-11.61%)	⬇️
...heus.HttpListener/PrometheusHttpListenerOptions.cs	100.00% <100.00%> (ø)
...ometheus.AspNetCore/PrometheusAspNetCoreOptions.cs	50.00% <0.00%> (-25.00%)	⬇️

... and 44 files with indirect coverage changes

[Bassardes]

I don't understand what happens with tests, locally it's all passes. I need help with it

[vishweshbankwar]

@Bassardes Could you address this #5305 (comment)

[Bassardes]

@vishweshbankwar Seems that I can't, because this merge c0eb638 wasn't done by me. I will try force push and merge master by myself

[cijothomas]

public bool EnableCounterTotalSuffix = true - alternate suggestion.

The default should be true as per https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/compatibility/prometheus_and_openmetrics.md#sums

[Bassardes]

Exporters SHOULD provide a configuration option to disable..

So I think DisableTotalNameSuffixForCounters will be better

[utpilla]

No need to mention "in Prometheus exporter". This CHANGELOG file is specific to Prometheus exporter.

[Bassardes]

fixed

[utpilla]

Same as https://github.com/open-telemetry/opentelemetry-dotnet/pull/5305/files#r1493103785

[Bassardes]

fixed

[CodeBlanch]

LGTM