Support zero-code configuration of resource detectors

[ezhang6811]

The AWS Go SDK currently supports several resource detectors for third party computing environments. It would be useful if customers could enable select detectors in the agent's TracerProvider, via an environment variable, to automatically add environment-specific attributes to the telemetry.

PHP instrumentation has a similar mechanism, see here.

Describe the solution you'd like

When auto-instrumentation is started it determines what resource detector to run based on configuration it is provided (i.e environment variables, configuration file).

To accomplish this, the autodetect package should be used.

Describe alternatives you've considered

• Write our own autodetect package (i.e. feat: support resource detector auto-configuration with OTEL_GO_DETECTORS env var #2438)

[MrAlias]

Copied from duplicate #2492.

For environment variable configuration, if we plan to support this method of configuration, the variable name will need to be prefixed with OTEL_GO_AUTO_. This matches our other configuration options for things that are not defined in the specification.

[MrAlias]

Copied from duplicate #2492.

Supporting a configuration file for this will mean we need to integration the OpenTelemetry declarative configuration. This is not stable yet, and support is Go is an ongoing work-in-progres.

I propose we do not attempt to solve this problem when resolving this issue. Meaning we stick to just supporting environment variables.