feat: Prometheus can auto set port (#2943)

* feat: config

* feat: prometheus auto set port

internal/api/prometheus_discovery.go

@@ -0,0 +1,113 @@
+package api
+
+import (
+	"encoding/json"
+	"github.com/gin-gonic/gin"
+	"github.com/openimsdk/open-im-server/v3/pkg/common/discoveryregister"
+	"github.com/openimsdk/open-im-server/v3/pkg/common/prommetrics"
+	"github.com/openimsdk/tools/apiresp"
+	"github.com/openimsdk/tools/discovery"
+	"github.com/openimsdk/tools/discovery/etcd"
+	"github.com/openimsdk/tools/errs"
+	"github.com/openimsdk/tools/log"
+	clientv3 "go.etcd.io/etcd/client/v3"
+	"net/http"
+)
+
+type PrometheusDiscoveryApi struct {
+	config *Config
+	client *clientv3.Client
+}
+
+func NewPrometheusDiscoveryApi(config *Config, client discovery.SvcDiscoveryRegistry) *PrometheusDiscoveryApi {
+	api := &PrometheusDiscoveryApi{
+		config: config,
+	}
+	if config.Discovery.Enable == discoveryregister.Etcd {
+		api.client = client.(*etcd.SvcDiscoveryRegistryImpl).GetClient()
+	}
+	return api
+}
+
+func (p *PrometheusDiscoveryApi) Enable(c *gin.Context) {
+	if p.config.Discovery.Enable != discoveryregister.Etcd {
+		c.JSON(http.StatusOK, []struct{}{})
+		c.Abort()
+	}
+}
+
+func (p *PrometheusDiscoveryApi) discovery(c *gin.Context, key string) {
+	eResp, err := p.client.Get(c, prommetrics.BuildDiscoveryKey(key))
+	if err != nil {
+		// Log and respond with an error if preparation fails.
+		apiresp.GinError(c, errs.WrapMsg(err, "etcd get err"))
+		return
+	}
+	if len(eResp.Kvs) == 0 {
+		c.JSON(http.StatusOK, []*prommetrics.Target{})
+	}
+
+	var (
+		resp = &prommetrics.RespTarget{
+			Targets: make([]string, 0, len(eResp.Kvs)),
+		}
+	)
+
+	for i := range eResp.Kvs {
+		var target prommetrics.Target
+		err = json.Unmarshal(eResp.Kvs[i].Value, &target)
+		if err != nil {
+			log.ZError(c, "prometheus unmarshal err", errs.Wrap(err))
+		}
+		resp.Targets = append(resp.Targets, target.Target)
+		if resp.Labels == nil {
+			resp.Labels = target.Labels
+		}
+	}
+
+	c.JSON(200, []*prommetrics.RespTarget{resp})
+}
+
+func (p *PrometheusDiscoveryApi) Api(c *gin.Context) {
+	p.discovery(c, prommetrics.APIKeyName)
+}
+
+func (p *PrometheusDiscoveryApi) User(c *gin.Context) {
+	p.discovery(c, p.config.Discovery.RpcService.User)
+}
+
+func (p *PrometheusDiscoveryApi) Group(c *gin.Context) {
+	p.discovery(c, p.config.Discovery.RpcService.Group)
+}
+
+func (p *PrometheusDiscoveryApi) Msg(c *gin.Context) {
+	p.discovery(c, p.config.Discovery.RpcService.Msg)
+}
+
+func (p *PrometheusDiscoveryApi) Friend(c *gin.Context) {
+	p.discovery(c, p.config.Discovery.RpcService.Friend)
+}
+
+func (p *PrometheusDiscoveryApi) Conversation(c *gin.Context) {
+	p.discovery(c, p.config.Discovery.RpcService.Conversation)
+}
+
+func (p *PrometheusDiscoveryApi) Third(c *gin.Context) {
+	p.discovery(c, p.config.Discovery.RpcService.Third)
+}
+
+func (p *PrometheusDiscoveryApi) Auth(c *gin.Context) {
+	p.discovery(c, p.config.Discovery.RpcService.Auth)
+}
+
+func (p *PrometheusDiscoveryApi) Push(c *gin.Context) {
+	p.discovery(c, p.config.Discovery.RpcService.Push)
+}
+
+func (p *PrometheusDiscoveryApi) MessageGateway(c *gin.Context) {
+	p.discovery(c, p.config.Discovery.RpcService.MessageGateway)
+}
+
+func (p *PrometheusDiscoveryApi) MessageTransfer(c *gin.Context) {
+	p.discovery(c, prommetrics.MessageTransferKeyName)
+}