Deprecate experimental/errorsource and remove experimental/errorsource/httpclient

[ivanahuckova]

This PR:

• removes experimental/errorsource/httpclient. This was used only in 4 data sources and I have removed the usage in all of them (Elasticsearch, Opensearch, Wavefront, Mongodb). If needed, I can move this to separate PR.

• exports ErrorWithSource that is basically renamed and exported errorWithSourceImpl.

• deprecates all methods/middlewares in experimental/errorource and instead uses backend error source stuff

Discussion points:

• I have gotten rid off override params when calling DownstremError and PluginError but I am unsure about this.
• Also previously had error in error source source and status, but I don't think we were really using a status. I got rid of it, but open to discussion.

From CI:

incompatible changes in github.com/grafana/grafana-plugin-sdk-go/experimental/errorsource

Error: changed from Error to github.com/grafana/grafana-plugin-sdk-go/experimental/status.ErrorWithSource
New: changed from func(error, github.com/grafana/grafana-plugin-sdk-go/experimental/status.Source, github.com/grafana/grafana-plugin-sdk-go/backend.Status) Error to func(error, github.com/grafana/grafana-plugin-sdk-go/experimental/status.Source, github.com/grafana/grafana-plugin-sdk-go/backend.Status) github.com/grafana/grafana-plugin-sdk-go/experimental/status.ErrorWithSource
SourceError: changed from func(github.com/grafana/grafana-plugin-sdk-go/experimental/status.Source, error, bool) Error to func(github.com/grafana/grafana-plugin-sdk-go/experimental/status.Source, error, bool) github.com/grafana/grafana-plugin-sdk-go/experimental/status.ErrorWithSource

All of these are saying that instead of Error we now have status.ErrorWithSource, which is what we want. All Error methods have been implemented for status.ErrorWithSource. The only thing that does not have is status backend.Status, but that was not used/exported anywhere.

incompatible changes github.com/grafana/grafana-plugin-sdk-go/experimental/errorsource/httpclient

package removed
Tis is done on purpose. This package was experimental and before removing, we ensured all data sources that were using it were migrated to not use it anymore.

[wbrowne]

LGTM. Awesome work - just a few minor things!

[wbrowne]

Are these changes unrelated?

[ivanahuckova]

It is related. Because in status_source package, for ErrorWithErrorSource.Error() method, we are prepending error source: https://github.com/grafana/grafana-plugin-sdk-go/blob/main/experimental/status/status_source.go#L86C1-L88C2

func (e errorWithSourceImpl) Error() string {
	return fmt.Errorf("%s error: %w", e.source, e.err).Error()
}

This is a change compared to error_source, where we only returned the error https://github.com/grafana/grafana-plugin-sdk-go/blob/main/experimental/errorsource/error_source.go#L22

// Error implements the interface
func (r Error) Error() string {
	return r.err.Error()
}

I could have changed it to {inp: "invalid-duration", err: regexp.MustCompile(^downstream error: time: invalid duration "?invalid-duration"?$)} as well.

But also what do you think about prepending error and should we not do it? 🤔

[wbrowne]

Ah 😄 I thought since the function didn't change the test shouldn't, but I didn't realize before it was a different path where it just showed the error.

But also what do you think about prepending error and should we not do it? 🤔

If you think it's necessary. Otherwise I wonder will the logger catch it anyway and put the source as a label? 🤔

[ivanahuckova]

If you think it's necessary.

I don't think it is necessary. If you don't think it is necessary, we can remove 🙂.

[wbrowne]

Sure let's keep it simple for now (and remove) and can always come back to improve if necessary 👍