List of attributes available to matches

GKE’s Istio add-on has the option to enable sending logging and tracing to Stackdriver (https://cloud.google.com/istio/docs/istio-on-gke/installing#tracing_and_logging) but by default it traces and logs absolutely everything inside the mesh, which is overwhelming. Really, all I want to do is trace and log inbound requests to istio-ingressgateway.

I know I can probably modify a match on the rule to facilitate this, and https://istio.io/docs/reference/config/policy-and-telemetry/istio.policy.v1beta1/#Rule has some examples, but I haven’t been able to find anywhere that lists all the attributes that I can use to construct a match clause. Does such a list exist anywhere?

The list of attributes is published here:

Not all attributes are populated for all requests. Usually you want to select traffic by context.protocol == "http" or context.protocol == "tcp" at the very least.

Thank you, I appreciate it!