feat(collector): support inline Base64 config via OPENTELEMETRY_COLLECTOR_CONFIG_CONTENT

[fatmcgav]

Adds a new OPENTELEMETRY_COLLECTOR_CONFIG_CONTENT environment variable that
accepts a standard Base64-encoded YAML collector config. The decoded content is
fed into the existing yamlprovider (yaml: URI scheme), so no new provider is
needed.

Resolution order:

1. OPENTELEMETRY_COLLECTOR_CONFIG_URI (existing, unchanged — warns if _CONTENT is also set)
2. OPENTELEMETRY_COLLECTOR_CONFIG_CONTENT (new — Base64-decoded YAML)
3. OPENTELEMETRY_COLLECTOR_CONFIG_FILE (deprecated fallback, unchanged)
4. /opt/collector-config/config.yaml (default)

If Base64 decoding fails an error is logged and the extension falls through to
the next option. NewCollector's signature is unchanged.

Co-Authored-By: Claude Sonnet 4.6 noreply@anthropic.com

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: fatmcgav / name: Gavin Williams (983c090)

[tylerbenson]

I don't think we can accept this here as it really should be something standardized on the collector side first.

[fatmcgav]

I don't think we can accept this here as it really should be something standardized on the collector side first.

Isn't this a lambda specific use case though? I can't personally see a need to use a base64 encoded string on any of the other common use cases..

[wpessers]

I'm with @tylerbenson on this. And on top of that, I believe it's already a thing that has been standardised in the collector upstream (see: open-telemetry/opentelemetry-collector#2910). We even already ship it in the collector extension:

opentelemetry-lambda/collector/internal/collector/collector.go

Line 79 in e285846

ProviderFactories: []confmap.ProviderFactory{fileprovider.NewFactory(), envprovider.NewFactory(), yamlprovider.NewFactory(), httpsprovider.NewFactory(), httpprovider.NewFactory(), s3provider.NewFactory(), secretsmanagerprovider.NewFactory()},

So you should just be able to use the env provider. If there's no further questions, I'll thus be closing this PR.

[fatmcgav]

Interesting.. I didn't find any docs related to that when I was looking... Will take another look next week though.. 👍

[wpessers]

@fatmcgav I'm willing to accept a PR to add some documentation for it here if that would make sense to you.

Since the extension layer basically ships a slimmed down version of the otel collector it's hard to decide what is worth documenting.

For now, I'll close the PR. If for any reason you can't get it to work with the env provider I'd advise opening an issue.