feat: build vehicle data platform and production pipeline

go/vehicle-gateway/internal/metrics/metrics.go

@@ -4,12 +4,16 @@ import (
 	"fmt"
 	"math"
 	"net/http"
+	"runtime"
 	"sort"
 	"strconv"
 	"strings"
 	"sync"
+	"time"
 )
 
+var processStartedAt = time.Now()
+
 type Labels map[string]string
 
 type Registry struct {
@@ -33,6 +37,56 @@ func NewRegistry() *Registry {
 	}
 }
 
+func RegisterServiceInfo(registry *Registry, service string) {
+	if registry == nil {
+		return
+	}
+	service = strings.TrimSpace(service)
+	if service == "" {
+		service = "vehicle-service"
+	}
+	registry.SetGauge("vehicle_service_info", Labels{"service": service}, 1)
+	RecordProcessRuntime(registry)
+}
+
+func RecordProcessRuntime(registry *Registry) {
+	if registry == nil {
+		return
+	}
+	var mem runtime.MemStats
+	runtime.ReadMemStats(&mem)
+	registry.SetGauge("vehicle_process_start_time_unix_seconds", nil, float64(processStartedAt.Unix()))
+	registry.SetGauge("vehicle_process_uptime_seconds", nil, time.Since(processStartedAt).Seconds())
+	registry.SetGauge("vehicle_process_heap_alloc_bytes", nil, float64(mem.HeapAlloc))
+	registry.SetGauge("vehicle_process_heap_sys_bytes", nil, float64(mem.HeapSys))
+	registry.SetGauge("vehicle_process_goroutines", nil, float64(runtime.NumGoroutine()))
+}
+
+func RegisterKafkaConsumerInfo(registry *Registry, service string, group string, topics []string) {
+	if registry == nil {
+		return
+	}
+	service = strings.TrimSpace(service)
+	if service == "" {
+		service = "vehicle-service"
+	}
+	group = strings.TrimSpace(group)
+	if group == "" {
+		return
+	}
+	for _, topic := range topics {
+		topic = strings.TrimSpace(topic)
+		if topic == "" {
+			continue
+		}
+		registry.SetGauge("vehicle_kafka_consumer_info", Labels{
+			"service": service,
+			"group":   group,
+			"topic":   topic,
+		}, 1)
+	}
+}
+
 func (r *Registry) IncCounter(name string, labels Labels) {
 	r.AddCounter(name, labels, 1)
 }
@@ -90,6 +144,13 @@ func (r *Registry) SetKafkaLag(name string, topic string, partition int, offset
 	}, float64(lag))
 }
 
+func RecordLastActivity(registry *Registry, name string, labels Labels) {
+	if registry == nil {
+		return
+	}
+	registry.SetGauge(name, labels, float64(time.Now().Unix()))
+}
+
 func (r *Registry) ObserveHistogram(name string, labels Labels, buckets []float64, value float64) {
 	name = strings.TrimSpace(name)
 	if r == nil || name == "" {
@@ -265,6 +326,7 @@ func NewHandler(registry *Registry) http.Handler {
 			http.NotFound(w, r)
 			return
 		}
+		RecordProcessRuntime(registry)
 		w.Header().Set("Content-Type", "text/plain; version=0.0.4; charset=utf-8")
 		_, _ = w.Write([]byte(registry.Render()))
 	})