[exporter/loadbalancing] Change config fields to use snake_case

[dmitryax]

Change AWS Cloud map resolver config fields from camelCase to snake_case.

The snake_case is required in OTel Collector config fields. It used to be enforced by tests in cmd/oteltestbedcol, but we had to disable them some time ago. Now, the tests are going to be enforced on every component independently. Hence, the camelCase config fields recently added with the new AWS Cloud Map resolver has to be fixed.

[songy23]

cc @jpkrohling

[andrzej-stencel]

I know it's a pain, but given that this component is in "Beta" stability, shouldn't we do the rename via a feature gate?

[dmitryax]

The feature was introduced only in 0.97.0 #27588 so I expect it's not widely used yet.

And I want to unblock #32328 sooner to avoid any other issues like this merged in.

So I'd rather make it as a breaking change but happy to hear what others think cc @jpkrohling @open-telemetry/collector-contrib-approvers

[andrzej-stencel]

The feature was introduced only in 0.97.0 #27588 so I expect it's not widely used yet.

Makes sense to me 🚀

[andrzej-stencel]

The README needs an update as well

[dmitryax]

Updated README

[crobert-1]

Another reference that needs fixed (output of an error message):

opentelemetry-collector-contrib/exporter/loadbalancingexporter/resolver_aws_cloudmap.go

Line 30 in adae336

errNoServiceName = errors.New("no Cloud Map serviceName specified to resolve the backends")

Some other references that should possibly be updated (log messages for config names):

opentelemetry-collector-contrib/exporter/loadbalancingexporter/resolver_aws_cloudmap.go

Lines 117 to 122 in adae336

	r.logger.Info("AWS CloudMap resolver started",
	zap.Stringp("serviceName", r.serviceName),
	zap.Stringp("namespaceName", r.namespaceName),
	zap.Uint16p("port", r.port),
	zap.String("healthStatus", string(*r.healthStatus)),
	zap.Duration("interval", r.resInterval), zap.Duration("timeout", r.resTimeout))

opentelemetry-collector-contrib/exporter/loadbalancingexporter/loadbalancer.go

Line 95 in adae336

awsCloudMapLogger := params.Logger.With(zap.String("resolver", "awsCloudMap"))

[dmitryax]

Thanks @crobert-1. Updated

[bryan-aguilar]

Suggested change

	service_name: aws-otel-col-service-name
	service_name: otel-col-service-name

Teeny tiny nit. Vendor agnostic right :)

[dmitryax]

Should I change aws-namespace as well? It's pretty hard to make AWS Cloud Map resolver vendor agnostic :)

[crobert-1]

I believe this is the last reference, but not necessarily essential:

opentelemetry-collector-contrib/exporter/loadbalancingexporter/loadbalancer.go

Line 95 in adae336

awsCloudMapLogger := params.Logger.With(zap.String("resolver", "awsCloudMap"))