Telemetry handler experience

[isvargasmsft]

2 things to address:

• The telemetry handler would only set the client request Id if not already present, allowing people to set it manually if they need some kind of end-to-end tracing.
• The telemetry handler should start a span and attach the client request id as a tag.

[isvargasmsft]

CC: @Ndiritu @SilasKenneth @shemogumbe

[Ndiritu]

For context, our telemetry handler currently adds 2 headers to requests: SdkVersion and client-request-id. Client Request ID can be manually set or defaults to a random UUID.

The current dev experience of customising client request ID when using service libraries:

$telemetryOption = new GraphTelemetryOption();
$telemetryOption->setClientRequestId('custom id');

$requestConfig = new UsersRequestBuilderGetRequestConfiguration();
$requestConfig->options = [$telemetryOption];

$response = $graphServiceClient->users()->get($requestConfig)->wait();

Dev exp. when using Graph core only:

$telemetryOption = new GraphTelemetryOption();
$telemetryOption->setClientRequestId('custom id');

$guzzleClient = GraphClientFactory::setTelemetryOption($telemetryOption)::create();
$response = $guzzleClient->get('/users');

Some improvements/gaps in the dev experience:

• can be shortened so that client request Id is set in the GraphTelemetryOption constructor
• current design could allow devs to overwrite SDK versions. We can find a way to "hide" those.

[Ndiritu]

@isvargasmsft the 2nd requirement isn't clear to me. Kindly clarify.

[isvargasmsft]

@baywet I understand you have more context on these 2 requests, is that right? These came from Seb.

[baywet]

@Ndiritu Open Telemetry is not yet implemented in PHP as far as I know, correct?

[Ndiritu]

Ah, didn't know we're referring to that.
Not yet.

[baywet]

right, so the second requirement can only be implemented when the tracing work is done. I suggest that you only implement the first now, and leave a note on the issue capturing tracing for the second.

[isvargasmsft]

Thank you very much @baywet

[baywet]

here is the related issue I'm referring to microsoft/kiota#1871