No reasonable way to use OTEL_LOG_LEVEL

[jtmalinowski]

Problem 1: just setting the logger uses a default level instead of the one from env configuration (https://github.com/open-telemetry/opentelemetry-js-api/blob/main/src/api/diag.ts#L75). Which means when setting a logger you need to fetch the ENV variable by yourself

diag.setLogger(new DiagConsoleLogger(), getEnv().OTEL_LOG_LEVEL);

which sort of defeats the point of the ENV variable?

Problem 2: tangentially, after setLogLevel was removed, there's no way to set the level and the logger independently (#9), which will make integration with Node ENV configuration tricky.

I'd propose:

• reviving setLogLevel
• change setLogger so that second argument, unless provided, doesn't change the log level
• allow setLogLevel and setLogger to be called in any order

Also, I'm happy to hear your thoughts, and send a PR when a resolution is decided.

ping @dyladan

[longility]

I was surprised when I set OTEL_LOG_LEVEL that it did nothing. I agree that is misleading.

[dyladan]

@MSNev what do you think? I agree that our current logging situation is not ideal and would like to make it easier to enable debugging.

[MSNev]

Agree, from (vague) memory this is why I had it before.

So

reviving setLogLevel

Yes

change setLogger so that second argument, unless provided, doesn't change the log level

Yes

allow setLogLevel and setLogger to be called in any order

Yes

[dyladan]

@MSNev or @longility would you like to make a PR?

[longility]

If I have time next week, I'll let you know. @MSNev feel free to take it you got time.

[MSNev]

I don't currently have cycles and I'm going to be OOF again in a few weeks, so go for it.

[longility]

If the logger is not set, should we be defaulting to a noop logger or DiagConsoleLogger?

[longility]

Another option could be if env var OTEL_LOG_LEVEL is set than we default to DiagConsoleLogger. If not set, then default to noop.

[dyladan]

Another option could be if env var OTEL_LOG_LEVEL is set than we default to DiagConsoleLogger. If not set, then default to noop.

Seems a reasonable compromise

[longility]

Acceptance criteria for whoever ends up tackling.

I may have time next week.

• If OTEL_LOG_LEVEL is defined, then default to DiagConsoleLogger.
• Logger set through setLogger should overwrite the default logger.
• If OTEL_LOG_LEVEL is not defined, then default to NoopLogger.
• setLogger to maintain existing log level and not overwrite with parameter default. (i.e. setLogger without log level provides should not overwrite the defined OTEL_LOG_LEVEL)
• Revive setLogLevel and allow setLogger and setLogLevel to be called and set in any order. Natural set order.

[longility]

If OTEL_LOG_LEVEL is defined, then default to DiagConsoleLogger.

I'm actually trying to figure out where this should go as getEnv() is in @opentelemetry/core and there isn't a pattern that I know of that is gets executed "automatically" without end user trigger from configuration.

Basically, without otel configuration and only env var OTEL_LOG_LEVEL where do we call something like if(getEnv().OTEL_LOG_LEVEL) diag.setLogger(new DiagConsoleLogger(), getEnv().OTEL_LOG_LEVEL);?

Personally, this is the only acceptance criteria that I desire among the others and it may be the 80% case. I think the other acceptance criterias are 20% case.

[jonaskello]

I tried for the longest time to make OTEL_LOG_LEVEL work and finally found this issue. Added the code below and now it works:

  api.diag.setLogger(new DiagConsoleLogger(), getEnv().OTEL_LOG_LEVEL);

[dyladan]

Moved this to the main repo where the API now resides open-telemetry/opentelemetry-js#3312