[maven-extension] Use the Otel SDK Auto Configuration Extension

[cyrille-leclerc]

Description:

Use the Otel SDK Auto Configuration Extension instead of reinventing all the configuration boilerplate.

ℹ️ Note that this PR doesn't extend the supported exporter (e.g. doesn't add support for OTLP HTTP...), we only have OTLP GRPC for the moment, it should be easy to extend as all the logic is provided by the Otel SDK Auto Configuration Extension now.

Existing Issue(s):

• [maven-extension] Figure out how to leverage standard autoconfigure #82

Testing:

We don't have auto integration tests yet so tests have to be done manually.

export OTEL_EXPORTER_OTLP_ENDPOINT="http://localhost:4317"
mvn verify

export OTEL_EXPORTER_OTLP_ENDPOINT="http://localhost:4317"
export OTEL_RESOURCE_ATTRIBUTES="foo=bar"
mvn verify

export OTEL_EXPORTER_OTLP_ENDPOINT="http://localhost:4317"
export OTEL_RESOURCE_ATTRIBUTES="service.name=MyMavenService"
mvn verify

Documentation:

No documentation added because the user experience didn't change.

Outstanding items:

Both items below are tracked in the code as TODO.

• Create an enhancement request on the Otel SDK Auto Configuration Extension to not register the shut down hook during initialisation if the system that embeds the Otel SDK manages the lifecycle. It doesn't cause problems with the Maven Plexus lifecycle but there is a risk.
• Explore how to use io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties to pass configuration parameters instead of shoving them in system properties.

[anuraaga]

There are improvements we can make in autoconfigure to help with the properties stuff indeed

[anuraaga]

Suggested change

	public static String getComaSeparatedString(Map<String, String> keyValuePairs) {
	public static String getCommaSeparatedString(Map<String, String> keyValuePairs) {

[cyrille-leclerc]

Fixed

[cyrille-leclerc]

There are improvements we can make in autoconfigure to help with the properties stuff indeed

Thanks @anuraaga , I am learning the SDK Auto Configure Extension APIs and already have done improvements adopting it on the Jenkins OpenTelemetry Plugin (I use io.opentelemetry.sdk.autoconfigure.spi.ConfigPropertiesinstead of showing my overwrites as system properties...). See jenkinsci/opentelemetry-plugin#185

I see this as an iterative journey with enhancement proposals on the SDK Auto Configure Extension APIs and refactoring of the usage of the extension in the Maven and Jenkins integrations.
Would that make sense to you?

[anuraaga]

Yeah ready to merge this after fixing the build in #114