NH-68421 Adjust service name, key usage when lambda

[tammy-baylis-swi]

Adjusts service name and service key requirements/usage when in lambda.

SW_APM_SERVICE_KEY was already not required for APM Python to be enabled in lambda, but if not provided was causing IndexError at _update_service_key_name. So added a condition in 5d7ba8b to only update key if not lambda.

The precedence of OTEL_SERVICE_NAME > AWS_LAMBDA_FUNCTION_NAME was already being respected by APM Python in lambda because of the otel-instrument wrapper. I added new helper _calculate_service_name_lambda anyway in case the wrapper fails or is not used in a lambda environment. Service name setting in lambda does not take agent_enabled into consideration like for APM proto service name setting (I'm pretty sure there's no use case beyond using function name?)

I manually tested by publishing a test layer (see ticket for ARN), applying to a function, and playing with different environment variables. Summary of outcome:

1. No OTEL_SERVICE_NAME --> exports to service with function name
2. No OTEL_SERVICE_NAME, OTEL_RESOURCE_ATTRIBUTES does have a service name --> Resource ignored and exports to service with function name
3. OTEL_SERVICE_NAME set --> exports to service of that awesome name

Please let me know what you think!

[xuan-cao-swi]

No OTEL_SERVICE_NAME --> exports to service with function name
No OTEL_SERVICE_NAME, OTEL_RESOURCE_ATTRIBUTES does have a service name --> Resource ignored and exports to service with function name
OTEL_SERVICE_NAME set --> exports to service of that awesome name

No sure if it's my browser problem, when I open the link, I got into the right service, but can't see the trace (Welcome to Observability by SolarWinds lands on my page)

[tammy-baylis-swi]

No sure if it's my browser problem, when I open the link, I got into the right service, but can't see the trace (Welcome to Observability by SolarWinds lands on my page)

Weird! I just checked and you are part of that Org on NA-02 data centre. So yeah possibly browser problem. Maybe clearing cookies/cache will help but also log you out of things 🙃