Investigate tools that check for API compatibility for go modules

[bogdandrutu]

Enable them for modules that we mark as stable.

[seankhliao]

As part of golang/go#26420 the Go team is experimenting with gorelease and the related apidiff

[Aneurysm9]

We have a need for similar capability in the Go SDK, so I can take this on.

[Aneurysm9]

I was able to use apidiff to generate an API snapshot from the v0.23.0 release and then compare against the current HEAD and it appears to correctly identify changes:

$ make apidiff-compare                                                     
Changes found in go.opentelemetry.io/collector/consumer/consumererror:
Incompatible changes:
- CombineErrors: removed
- PartialError: removed
- PartialLogsError: removed
- PartialMetricsError: removed
- PartialTracesError: removed
Compatible changes:
- AsLogs: added
- AsMetrics: added
- AsTraces: added
- Combine: added
- Logs: added
- Metrics: added
- NewLogs: added
- NewMetrics: added
- NewTraces: added
- Traces: added
Changes found in go.opentelemetry.io/collector/consumer/pdata:
Incompatible changes:
- DoubleSummary: removed
- DoubleSummaryDataPoint: removed
- DoubleSummaryDataPointSlice: removed
- Metric.DoubleSummary: removed
- MetricDataTypeDoubleSummary: removed
- NewDoubleSummary: removed
- NewDoubleSummaryDataPoint: removed
- NewDoubleSummaryDataPointSlice: removed
Compatible changes:
- Metric.Summary: added
- MetricDataTypeSummary: added
- NewSummary: added
- NewSummaryDataPoint: added
- NewSummaryDataPointSlice: added
- Summary: added
- SummaryDataPoint: added
- SummaryDataPointSlice: added
Changes found in go.opentelemetry.io/collector/exporter/exporterhelper:
Incompatible changes:
- CreateTraceExporter: removed
Compatible changes:
- CreateTracesExporter: added
Changes found in go.opentelemetry.io/collector/obsreport:
Incompatible changes:
- NewExporter: changed from func(go.opentelemetry.io/collector/config/configtelemetry.Level, string) *Exporter to func(ExporterSettings) *Exporter
Compatible changes:
- ExporterSettings: added

This is currently operating on all packages in the go.opentelemetry.io/collector module. apidiff appears to not allow specifying a package version at runtime and must be in the directory containing go.mod for the package's module when generating a snapshot of the package API in order to use the files on disk, so additional work will be required to support scanning multiple modules.

$ apidiff go.opentelemetry.io/collector/exporter/[email protected] go.opentelemetry.io/collector/exporter/exporterhelper
loading go.opentelemetry.io/collector/exporter/[email protected]: -: can only use path@version syntax with 'go get' and 'go install' in module-aware mode

@bogdandrutu do you want my to put up a PR with things as I have it now, or should I continue working on being able to operate on a per-module basis? Chances are I wouldn't be able to pick up that work again until next week.

[bogdandrutu]

@Aneurysm9 how do you suggest to enforce this? I am confident that unless we run this every PR we will forget about it. Maybe a github action that fails if changes are added to the PR?

[alolita]

@Aneurysm9 can you create an issue for building a GitHub Action workflow to check when changes are added (its an API diff check in a GHA workflow)?

cc @mxiamxia

[bogdandrutu]

Probably we should have a github action that compares the PR with head and adds a comment or fails if changes are identified

[alolita]

Closing this issue as discussed with @bogdandrutu

New issue is #3220