feat: label build identity in metrics

internal/observability/catalog.go

@@ -1,6 +1,6 @@
 package observability
 
-import "runtime"
+import "git.yuntuo.hk/k2safe/orbit/internal/buildinfo"
 
 var methods = []string{"GET", "POST", "PATCH", "PUT", "DELETE", "HEAD", "OPTIONS", "OTHER"}
 var routes = []string{"health_live", "health_ready", "worker_connect", "event_connect", "tasks", "queues", "workflows", "workflow_definitions", "schedules", "subscriptions", "application_resources", "other"}
@@ -16,6 +16,7 @@ var eventTypes = []string{"task.accepted", "task.started", "task.succeeded", "ta
 // Adding a metric therefore requires a code review; no user identifier is valid.
 func catalog() map[string]descriptor {
 	httpLabels := map[string][]string{"method": methods, "route": routes, "status_class": statusClasses}
+	build := buildinfo.Current()
 	c := map[string]descriptor{
 		"orbit_http_requests_total":                          {counter, "Completed HTTP responses, including successful upgrade handshakes", httpLabels},
 		"orbit_http_request_duration_seconds":                {histogram, "HTTP response or upgrade handshake duration in seconds", httpLabels},
@@ -29,7 +30,7 @@ func catalog() map[string]descriptor {
 		"orbit_process_start_time_seconds":                   {gauge, "Unix time when the Orbit metrics registry was started", nil},
 		"orbit_process_uptime_seconds":                       {gauge, "Monotonic elapsed time since metrics registry startup", nil},
 		"orbit_go_goroutines":                                {gauge, "Current Go goroutine count", nil},
-		"orbit_build_info":                                   {gauge, "Orbit Go runtime build information", map[string][]string{"go_version": {runtime.Version()}}},
+		"orbit_build_info":                                   {gauge, "Orbit build and protocol information", map[string][]string{"go_version": {build.GoVersion}, "version": {build.Version}, "revision": {build.Revision}}},
 	}
 	for name, help := range map[string]string{
 		"open": "Open MySQL connections", "in_use": "MySQL connections currently in use", "idle": "Idle MySQL connections", "max_open": "Configured maximum open MySQL connections",