Fallback to Generic Logger Output

[bflad]

terraform-plugin-log version

v0.3.0

Use cases

For much of the terraform-plugin-log logging logic, it will fallback to dropping messages when the context.Context is not appropriately setup, e.g.

terraform-plugin-log/tflog/provider.go

Lines 31 to 38 in 94541a8

	if logger == nil {
	// this essentially should never happen in production
	// the root logger for provider code should be injected
	// by whatever SDK the provider developer is using, so
	// really this is only likely in unit tests, at most
	// so just making this a no-op is fine
	return
	}

In production, is quite trivial for provider developers to get into situations where the context.Context is not setup properly. For example, using the non-context-aware fields of github.com/hashicorp/terraform-plugin-sdk/helper/schema.Resource or using any SDK, errantly using a separate context.Context that was not setup (e.g. via context.Background() or context.TODO()).

Another use case is SDK-based unit testing, where it takes some effort to setup the logging contexts or its easy to miss in each and every test.

Not having any log output with no indication of an issue is more confusing than expecting everyone downstream to figure out the issue on their own.

Proposal

If a logging message is to be written, but the appropriate logging context is not available, fallback to a last resort github.com/hashicorp/hc-log.Logger and write to it instead. On first usage of the last resort Logger, it should also output a warning message about the missing context-based Logger, so provider or SDK developers can understand any differences in logging behavior.

References

• https://discuss.hashicorp.com/t/terraform-plugin-log-not-outputting-logs/38590/2

[bflad]

Another way provider developers can get into this situation is if they are using a github.com/hashicorp/terraform-plugin-sdk or github.com/hashicorp/terraform-plugin-framework Go dependency before the introduction of the logging context handling -- prior to v2.10.0 and v0.6.0 respectfully.

[ghost]

Same here tflog is not printing output to console for me. Just starting with Go and tf provider development so everything is still confusing to me...

I tried:
tflog.Warn(context.TODO(), string(postBody))

But I guess this is not working because I am using TODO context? What should I use instead?

[ghost]

Ok, i resolved it by passing the context from parents to children and using that instead of "dummy" context