playground: fix tiproxy metrics addr (pingcap#2299)

components/playground/instance/instance.go

@@ -47,6 +47,12 @@ type instance struct {
 	BinPath    string
 }
 
+// MetricAddr will be used by prometheus scrape_configs.
+type MetricAddr struct {
+	Targets []string          `json:"targets"`
+	Labels  map[string]string `json:"labels"`
+}
+
 // Instance represent running component
 type Instance interface {
 	Pid() int
@@ -59,16 +65,16 @@ type Instance interface {
 	LogFile() string
 	// Uptime show uptime.
 	Uptime() string
-	// StatusAddrs return the address to pull metrics.
-	StatusAddrs() []string
+	// MetricAddr return the address to pull metrics.
+	MetricAddr() MetricAddr
 	// Wait Should only call this if the instance is started successfully.
 	// The implementation should be safe to call Wait multi times.
 	Wait() error
 }
 
-func (inst *instance) StatusAddrs() (addrs []string) {
+func (inst *instance) MetricAddr() (r MetricAddr) {
 	if inst.Host != "" && inst.StatusPort != 0 {
-		addrs = append(addrs, utils.JoinHostPort(inst.Host, inst.StatusPort))
+		r.Targets = append(r.Targets, utils.JoinHostPort(inst.Host, inst.StatusPort))
 	}
 	return
 }

components/playground/instance/tiproxy.go

@@ -54,6 +54,15 @@ func NewTiProxy(binPath string, dir, host, configPath string, id int, port int,
 	return tiproxy
 }
 
+// MetricAddr implements Instance interface.
+func (c *TiProxy) MetricAddr() (r MetricAddr) {
+	r.Targets = append(r.Targets, utils.JoinHostPort(c.Host, c.StatusPort))
+	r.Labels = map[string]string{
+		"__metrics_path__": "/api/metrics",
+	}
+	return
+}
+
 // Start implements Instance interface.
 func (c *TiProxy) Start(ctx context.Context, version utils.Version) error {
 	endpoints := pdEndpoints(c.pds, true)

components/playground/monitor.go

@@ -29,24 +29,20 @@ import (
 )
 
 // ref: https://prometheus.io/docs/prometheus/latest/configuration/configuration/#file_sd_config
-func (m *monitor) renderSDFile(cid2targets map[string][]string) error {
-	type Item struct {
-		Targets []string          `json:"targets"`
-		Labels  map[string]string `json:"labels"`
-	}
-
-	cid2targets["prometheus"] = []string{utils.JoinHostPort(m.host, m.port)}
+func (m *monitor) renderSDFile(cid2targets map[string]instance.MetricAddr) error {
+	cid2targets["prometheus"] = instance.MetricAddr{Targets: []string{utils.JoinHostPort(m.host, m.port)}}
 
-	var items []Item
+	var items []instance.MetricAddr
 
-	for id, targets := range cid2targets {
-		item := Item{
-			Targets: targets,
-			Labels: map[string]string{
-				"job": id,
-			},
+	for id, t := range cid2targets {
+		it := instance.MetricAddr{
+			Targets: t.Targets,
+			Labels:  map[string]string{"job": id},
+		}
+		for k, v := range t.Labels {
+			it.Labels[k] = v
 		}
-		items = append(items, item)
+		items = append(items, it)
 	}
 
 	data, err := json.MarshalIndent(&items, "", "\t")

components/playground/playground.go

@@ -1289,12 +1289,10 @@ func (p *Playground) renderSDFile() error {
 		return nil
 	}
 
-	cid2targets := make(map[string][]string)
+	cid2targets := make(map[string]instance.MetricAddr)
 
 	_ = p.WalkInstances(func(cid string, inst instance.Instance) error {
-		targets := cid2targets[cid]
-		targets = append(targets, inst.StatusAddrs()...)
-		cid2targets[cid] = targets
+		cid2targets[cid] = inst.MetricAddr()
 		return nil
 	})