feat(pubsub): extract trace information

Pass a context that contains trace information extracted from the
incoming message, allowing traces to span from publishers over to
subscribers.

In order for publishers to include tracing information, the pubsub
client should be created with:
```go
client, err := pubsub.NewClientWithConfig(
	ctx,
	cloudrunner.Runtime(ctx).ProjectID,
	&pubsub.ClientConfig{
		EnableOpenTelemetryTracing: true,
	},
```

Depends on googleapis/google-cloud-go#10827
which is included in
[v1.43.0](https://github.com/googleapis/google-cloud-go/releases/tag/pubsub%2Fv1.43.0).

cloudpubsub/httphandler.go

@@ -7,9 +7,11 @@ import (
 	"net/http"
 	"time"
 
+	"cloud.google.com/go/pubsub"
 	"cloud.google.com/go/pubsub/apiv1/pubsubpb"
 	"go.einride.tech/cloudrunner/cloudrequestlog"
 	"go.einride.tech/cloudrunner/cloudstatus"
+	"go.opentelemetry.io/otel/propagation"
 	"google.golang.org/grpc/status"
 	"google.golang.org/protobuf/types/known/timestamppb"
 )
@@ -55,6 +57,19 @@ func (fn httpHandlerFn) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		fields.Add(slog.Any("pubsubMessage", &pubsubMessage))
 	}
 	ctx := withSubscription(r.Context(), payload.Subscription)
+	carrier := pubsub.NewMessageCarrierFromPB(&pubsubMessage)
+	b, err := json.Marshal(carrier)
+	if err != nil {
+		slog.WarnContext(ctx, "unable to marshal carrier", slog.Any("error", err))
+	} else {
+		slog.InfoContext(
+			ctx,
+			"extracted carrier trace from pubsub",
+			slog.String("trace", string(b)),
+			slog.Any("attributes", pubsubMessage.Attributes),
+		)
+	}
+	ctx = propagation.TraceContext{}.Extract(ctx, pubsub.NewMessageCarrierFromPB(&pubsubMessage))
 	if err := fn(ctx, &pubsubMessage); err != nil {
 		if fields, ok := cloudrequestlog.GetAdditionalFields(r.Context()); ok {
 			fields.Add(slog.Any("error", err))

go.mod

@@ -43,6 +43,7 @@ require (
 	cloud.google.com/go v0.117.0 // indirect
 	cloud.google.com/go/auth v0.13.0 // indirect
 	cloud.google.com/go/auth/oauth2adapt v0.2.6 // indirect
+	cloud.google.com/go/iam v1.2.2 // indirect
 	cloud.google.com/go/longrunning v0.6.2 // indirect
 	cloud.google.com/go/monitoring v1.21.2 // indirect
 	cloud.google.com/go/trace v1.11.2 // indirect

go.sum

@@ -9,6 +9,8 @@ cloud.google.com/go/compute/metadata v0.6.0 h1:A6hENjEsCDtC1k8byVsgwvVcioamEHvZ4
 cloud.google.com/go/compute/metadata v0.6.0/go.mod h1:FjyFAW1MW0C203CEOMDTu3Dk1FlqW3Rga40jzHL4hfg=
 cloud.google.com/go/iam v1.2.2 h1:ozUSofHUGf/F4tCNy/mu9tHLTaxZFLOUiKzjcgWHGIA=
 cloud.google.com/go/iam v1.2.2/go.mod h1:0Ys8ccaZHdI1dEUilwzqng/6ps2YB6vRsjIe00/+6JY=
+cloud.google.com/go/kms v1.20.1 h1:og29Wv59uf2FVaZlesaiDAqHFzHaoUyHI3HYp9VUHVg=
+cloud.google.com/go/kms v1.20.1/go.mod h1:LywpNiVCvzYNJWS9JUcGJSVTNSwPwi0vBAotzDqn2nc=
 cloud.google.com/go/logging v1.13.0 h1:7j0HgAp0B94o1YRDqiqm26w4q1rDMH7XNRU34lJXHYc=
 cloud.google.com/go/logging v1.13.0/go.mod h1:36CoKh6KA/M0PbhPKMq6/qety2DCAErbhXT62TuXALA=
 cloud.google.com/go/longrunning v0.6.2 h1:xjDfh1pQcWPEvnfjZmwjKQEcHnpz6lHjfy7Fo0MK+hc=
@@ -150,6 +152,8 @@ github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9de
 github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yusufpapurcu/wmi v1.2.4 h1:zFUKzehAFReQwLys1b/iSMl+JQGSCSjtVqQn9bBrPo0=
 github.com/yusufpapurcu/wmi v1.2.4/go.mod h1:SBZ9tNy3G9/m5Oi98Zks0QjeHVDvuK0qfxQmPyzfmi0=
+go.einride.tech/aip v0.68.0 h1:4seM66oLzTpz50u4K1zlJyOXQ3tCzcJN7I22tKkjipw=
+go.einride.tech/aip v0.68.0/go.mod h1:7y9FF8VtPWqpxuAxl0KQWqaULxW4zFIesD6zF5RIHHg=
 go.einride.tech/protobuf-sensitive v0.8.0 h1:EoeKBbjJFc+K1xvfut6Wat0AY1eMAdmBYmGiBdK8Plw=
 go.einride.tech/protobuf-sensitive v0.8.0/go.mod h1:YkjV9z/m+HxFxtvdEUKdjUhImB5QjTD+mzqAqP5pAnU=
 go.opencensus.io v0.24.0 h1:y73uSU6J157QMP2kn2r30vwW1A2W2WFwSCGnAVxeaD0=