lazyload: avoid exclusive port for global-sidecar health check

staging/src/slime.io/slime/modules/lazyload/cmd/proxy/main.go

@@ -20,6 +20,9 @@ const (
 )
 
 func main() {
+ // indicate whether probe port is same with one of wormhole ports
+ dupPort := false
+
  // set log config
  logLevel := os.Getenv(EnvLogLevel)
  if logLevel == "" {
@@ -34,26 +37,18 @@ func main() {
  TimestampFormat: time.RFC3339,
  })
 
- // start health check server
- probePort := os.Getenv(EnvProbePort)
- go func() {
- handler := &proxy.HealthzProxy{}
- log.Println("Starting health check on", ":" + probePort)
- if err := http.ListenAndServe(":" + probePort, handler); err != nil {
- log.Fatal("ListenAndServe:", err)
- }
- }()
+ probePort, err := strconv.Atoi(os.Getenv(EnvProbePort))
+ if err != nil {
+ log.Errorf("wrong probe port value %s", os.Getenv(EnvProbePort))
+ os.Exit(1)
+ }
 
- // start multi ports defined in WormholePorts
+ // TODO start multi ports defined in WormholePorts in disaster backup scenario
+ // TODO if not, just start 80
  wormholePorts := os.Getenv(EnvWormholePorts)
  wormholePortsArr := strings.Split(wormholePorts, ",")
  var whPorts []int
  for _, whp := range wormholePortsArr {
- if whp == probePort {
- log.Errorf("wormholePort can not be %s, which is reserved for health check", probePort)
- os.Exit(1)
- }
-
  p, err := strconv.Atoi(whp)
  if err != nil {
  log.Errorf("wrong wormholePort value %s", whp)
@@ -66,6 +61,11 @@ func main() {
  for _, whPort := range whPorts {
  wg.Add(1)
  handler := &proxy.Proxy{WormholePort: whPort}
+ if whPort == probePort {
+ log.Println("Starting health check on", ":"+os.Getenv(EnvProbePort))
+ handler.IsProbe = true
+ dupPort = true
+ }
  go func(whPort int) {
  log.Println("Starting proxy on", "0.0.0.0"+":"+strconv.Itoa(whPort))
  if err := http.ListenAndServe("0.0.0.0"+":"+strconv.Itoa(whPort), handler); err != nil {
@@ -75,6 +75,16 @@ func main() {
  }(whPort)
  }
 
+ if !dupPort {
+ go func() {
+ handler := &proxy.HealthzProxy{}
+ log.Println("Starting health check on", ":"+os.Getenv(EnvProbePort))
+ if err := http.ListenAndServe(":"+os.Getenv(EnvProbePort), handler); err != nil {
+ log.Fatal("ListenAndServe:", err)
+ }
+ }()
+ }
+
  wg.Wait()
  log.Infof("All servers exited.")
 }

staging/src/slime.io/slime/modules/lazyload/pkg/proxy/http.go

@@ -18,21 +18,30 @@ const (
  HeaderOrigDest = "Slime-Orig-Dest"
 )
 
-type HealthzProxy struct{}
-
-func (p *HealthzProxy) ServeHTTP(w http.ResponseWriter, req *http.Request) {
- // health check
+func healthCheck(w http.ResponseWriter, req *http.Request) {
  if req.RequestURI == "/healthz/live" || req.RequestURI == "/healthz/ready" {
- w.Write([]byte("Healthy!"))
+ w.WriteHeader(200)
  return
  }
+ w.WriteHeader(500)
+}
+
+type HealthzProxy struct{}
+
+func (p *HealthzProxy) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+ healthCheck(w, req)
 }
 
 type Proxy struct {
  WormholePort int
+ IsProbe bool
 }
 
 func (p *Proxy) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+ if p.IsProbe {
+ healthCheck(w, req)
+ }
+
  var (
  reqCtx = req.Context()
  reqHost = req.Host