feat: mysql and redis metric support (#2355)

* feat: mysql and redis metric support

* feat: mysql and redis metric support

* feat: mysql and redis metric support

Co-authored-by: dawn.zhou <dawn.zhou@yijinin.com>

core/metric/counter_test.go

@@ -3,6 +3,8 @@ package metric
 import (
 	"testing"
 
+	"github.com/zeromicro/go-zero/core/prometheus"
+
 	"github.com/prometheus/client_golang/prometheus/testutil"
 	"github.com/stretchr/testify/assert"
 )
@@ -21,6 +23,7 @@ func TestNewCounterVec(t *testing.T) {
 }
 
 func TestCounterIncr(t *testing.T) {
+	startAgent()
 	counterVec := NewCounterVec(&CounterVecOpts{
 		Namespace: "http_client",
 		Subsystem: "call",
@@ -37,6 +40,7 @@ func TestCounterIncr(t *testing.T) {
 }
 
 func TestCounterAdd(t *testing.T) {
+	startAgent()
 	counterVec := NewCounterVec(&CounterVecOpts{
 		Namespace: "rpc_server",
 		Subsystem: "requests",
@@ -51,3 +55,11 @@ func TestCounterAdd(t *testing.T) {
 	r := testutil.ToFloat64(cv.counter)
 	assert.Equal(t, float64(33), r)
 }
+
+func startAgent() {
+	prometheus.StartAgent(prometheus.Config{
+		Host: "127.0.0.1",
+		Port: 9101,
+		Path: "/metrics",
+	})
+}