more metrics infrastructure (#74, #76)

controller/metrics.go

@@ -1,7 +1,14 @@
 package controller
 
 import (
+	"github.com/openziti-test-kitchen/zrok/zrokdir"
+	"github.com/openziti/sdk-golang/ziti"
+	"github.com/openziti/sdk-golang/ziti/config"
+	"github.com/openziti/sdk-golang/ziti/edge"
+	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
+	"net"
+	"time"
 )
 
 type MetricsConfig struct {
@@ -17,9 +24,11 @@ type InfluxConfig struct {
 }
 
 type metricsAgent struct {
-	cfg      *MetricsConfig
-	shutdown chan struct{}
-	joined   chan struct{}
+	cfg       *MetricsConfig
+	shutdown  chan struct{}
+	joined    chan struct{}
+	zCtx      ziti.Context
+	zListener edge.Listener
 }
 
 func newMetricsAgent(cfg *MetricsConfig) *metricsAgent {
@@ -35,7 +44,48 @@ func (mtr *metricsAgent) run() {
 	defer logrus.Info("exiting")
 	defer close(mtr.joined)
 
+	if err := mtr.bindService(); err != nil {
+		logrus.Errorf("error binding metrics service: %v", err)
+		return
+	}
+
 	<-mtr.shutdown
+
+	if err := mtr.zListener.Close(); err != nil {
+		logrus.Errorf("error closing metrics service listener: %v", err)
+	}
+}
+
+func (mtr *metricsAgent) bindService() error {
+	zif, err := zrokdir.ZitiIdentityFile("ctrl")
+	if err != nil {
+		return errors.Wrap(err, "error getting 'ctrl' identity")
+	}
+	zCfg, err := config.NewFromFile(zif)
+	if err != nil {
+		return errors.Wrap(err, "error loading 'ctrl' identity")
+	}
+	mtr.zCtx = ziti.NewContextWithConfig(zCfg)
+	opts := &ziti.ListenOptions{
+		ConnectTimeout: 5 * time.Minute,
+		MaxConnections: 1024,
+	}
+	mtr.zListener, err = mtr.zCtx.ListenWithOptions(mtr.cfg.ServiceName, opts)
+	if err != nil {
+		return errors.Wrapf(err, "error listening for metrics on '%v'", mtr.cfg.ServiceName)
+	}
+	return nil
+}
+
+func (mtr *metricsAgent) listen() {
+	for {
+		conn, err := mtr.zListener.Accept()
+		if err != nil {
+			logrus.Errorf("error accepting: %v", err)
+			return
+		}
+		go newMetricsHandler(conn).run()
+	}
 }
 
 func (mtr *metricsAgent) stop() {
@@ -45,3 +95,18 @@ func (mtr *metricsAgent) stop() {
 func (mtr *metricsAgent) join() {
 	<-mtr.joined
 }
+
+type metricsHandler struct {
+	conn net.Conn
+}
+
+func newMetricsHandler(conn net.Conn) *metricsHandler {
+	return &metricsHandler{conn}
+}
+
+func (mh *metricsHandler) run() {
+	logrus.Infof("handling metrics connection: %v", mh.conn.RemoteAddr())
+	if err := mh.conn.Close(); err != nil {
+		logrus.Errorf("error closing metrics connection")
+	}
+}