logging: incorrect parsing of Trace Context header without sampling indicator

[broady]

Sometimes the header doesn't include the sampling information.

e.g.:

X-Cloud-Trace-Context: 6518720b40e1efacf2299758d229210a/14866474463603563926

Current assumption:

var reCloudTraceContext = regexp.MustCompile(`([a-f\d]+)/([a-f\d]+);o=(\d)`)

[odeke-em]

Hey @broady, thanks for this report!

Coming here from the trace-context specification for Stackdriver https://cloud.google.com/trace/docs/troubleshooting#force-trace

and also from the CL that I sent to enforce it in commit 392bd16#diff-ad8a2265fa17b7808fca5ae77cada94f are we asking that we parse a malformed X-Cloud-Trace-Context? That is a header value without the ;o=(\d) part?

[broady]

Hm, if this is indeed the intention of the spec then I need to file a bug against App Engine.

[freelerobot]

Hi @broady fyi at the client library level, we now accept user input where sampleTrace field is optional (in which case, we default sampleTrace to false).

However, this fix doesn't solve the lower lvl issue where the service is not flagging it as true when it should be. Thanks!