otlpHTTPLogExporter, otlpGRPCLogExporter, etc do not support fields like OTLP.Certificate

[mattsains]

Description

The OTLP configuration type has fields Certificate, ClientCertificate, ClientKey, HeadersList and Insecure:

opentelemetry-go-contrib/config/generated_config.go

Lines 258 to 264 in 6e79f7c

	Certificate *string `json:"certificate,omitempty" yaml:"certificate,omitempty" mapstructure:"certificate,omitempty"`
	// ClientCertificate corresponds to the JSON schema field "client_certificate".
	ClientCertificate *string `json:"client_certificate,omitempty" yaml:"client_certificate,omitempty" mapstructure:"client_certificate,omitempty"`
	// ClientKey corresponds to the JSON schema field "client_key".
	ClientKey *string `json:"client_key,omitempty" yaml:"client_key,omitempty" mapstructure:"client_key,omitempty"`

These fields are not read/supported by constructors like otlpGRPCLogExporter, otlpHTTPLogExporter, otlpHTTPMetricExporter, otlpGRPCMetricExporter, otlpGRPCSpanExporter and otlpHTTPSpanExporter.

Environment

• OS: N/A
• Architecture: N/A
• Go Version: N/A
• config version: 6e79f7c, 1.32.0

Steps To Reproduce

An example of how to trigger this is to call NewSDK specifying a custom certificate. This certificate will not be used when connecting to the trace endpoint specified.

Expected behavior

These fields should be respected when creating log, trace and metric exporters.

[mattsains]

I think that this code is used in the collector's internal telemetry exporting too: https://github.com/open-telemetry/opentelemetry-collector/blob/9d2685f404ef65b46152ae80c36ff84f303e3cc6/service/service.go#L133C5-L138C7

I believe the fix for this is as simple as something like this case for Certificate:

if otlpConfig.Certificate != nil {
	creds, err := credentials.NewClientTLSFromFile(*otlpConfig.Certificate, "")
	opts = append(opts, otlptracegrpc.WithTLSCredentials(creds))
}

If that sounds good to maintainers, I'd be glad to submit a PR for it, I'd just like to know I'm barking up the right tree first.

[ms-jcorley]

I created a PR for a small part of this in the collector repo:
open-telemetry/opentelemetry-collector#11633

[dmathieu]

cc @pellared @codeboten as code owners.

[codeboten]

Thanks @mattsains & @ms-jcorley for taking a look at this. I opened a PR that takes the code submitted in open-telemetry/opentelemetry-collector#11633 to get the Certificate config sorted. @mattsains if you have time to open follow up PRs for the other fields that'd be great