(MAINT) Refactor telemetry to pass root span name

Prior to this commit, the telemetry package hard coded the root span to
execution; this commit modifies the Start function to take an additional
paramater, rootCommandName, which is passed when called in main to ensure
that the root span is appropriately named. This will enable broader reuse
by other PDK tools such as PRM.

This commit also renames the variable containing the root span in main
from span to parentSpan in preparation for spinning up a child span in
main instead of in each subcommand.

main.go

@@ -30,8 +30,8 @@ var (
 func main() {
 	// Telemetry must be initialized before anything else;
 	// If the telemetry build tag was not passed, this is all null ops
-	ctx, traceProvider, span := telemetry.Start(context.Background(), honeycomb_api_key, honeycomb_dataset)
-	defer telemetry.ShutDown(ctx, traceProvider, span)
+	ctx, traceProvider, parentSpan := telemetry.Start(context.Background(), honeycomb_api_key, honeycomb_dataset, "pct")
+	defer telemetry.ShutDown(ctx, traceProvider, parentSpan)
 
 	var rootCmd = root.CreateRootCommand()
 

pkg/telemetry/telemetry.go

@@ -22,7 +22,7 @@ import (
 	"go.opentelemetry.io/otel/sdk/resource"
 )
 
-func Start(ctx context.Context, honeycomb_api_key string, honeycomb_dataset string) (context.Context, *sdktrace.TracerProvider, trace.Span) {
+func Start(ctx context.Context, honeycomb_api_key string, honeycomb_dataset string, rootSpanName string) (context.Context, *sdktrace.TracerProvider, trace.Span) {
 	var tp *sdktrace.TracerProvider
 	// if telemetry is turned on and honeycomb is configured, hook it up
 	api_key_set := honeycomb_api_key != "not_set" && honeycomb_api_key != ""
@@ -76,7 +76,7 @@ func Start(ctx context.Context, honeycomb_api_key string, honeycomb_dataset stri
 	tracer := otel.Tracer("pct")
 
 	var span trace.Span
-	ctx, span = tracer.Start(ctx, "execution")
+	ctx, span = tracer.Start(ctx, rootSpanName)
 
 	// The Protected ID is hashed base on application name to prevent any
 	// accidental leakage of a reversable ID.

pkg/telemetry/telemetry_noop.go

@@ -7,7 +7,7 @@ import (
 	"context"
 )
 
-func Start(ctx context.Context, honeycomb_api_key string, honeycomb_dataset string) (context.Context, string, string) {
+func Start(ctx context.Context, honeycomb_api_key string, honeycomb_dataset string, rootSpanName string) (context.Context, string, string) {
 	// deliberately does nothing
 	return ctx, "", ""
 }