veyron/services/proxy/proxyd: Add optional healthz server.
Add an option to run a separate HTTP server that just returns "ok" to
every request. This is useful when the proxy sits behind a load
balancer. Without this, the load balancer has no way to know whether the
proxy is running.
Change-Id: Iacb69444e9693e717998bc534ade8a6b2b020921
diff --git a/services/proxy/proxyd/main.go b/services/proxy/proxyd/main.go
index f30b10f..6e4d15c 100644
--- a/services/proxy/proxyd/main.go
+++ b/services/proxy/proxyd/main.go
@@ -18,11 +18,12 @@
func main() {
var (
// TODO(rthellend): Remove the address and protocol flags when the config manager is working.
- address = flag.String("address", ":0", "Network address the proxy listens on")
- pubAddress = flag.String("published_address", "", "Network address the proxy publishes. If empty, the value of --address will be used")
- protocol = flag.String("protocol", "tcp", "Network type the proxy listens on")
- httpAddr = flag.String("http", ":14142", "Network address on which the HTTP debug server runs")
- name = flag.String("name", "", "Name to mount the proxy as")
+ address = flag.String("address", ":0", "Network address the proxy listens on")
+ pubAddress = flag.String("published_address", "", "Network address the proxy publishes. If empty, the value of --address will be used")
+ protocol = flag.String("protocol", "tcp", "Network type the proxy listens on")
+ httpAddr = flag.String("http", ":14142", "Network address on which the HTTP debug server runs")
+ healthzAddr = flag.String("healthz_address", "", "Network address on which the HTTP healthz server runs. It is intended to be used with a load balancer. The load balancer must be able to reach this address in order to verify that the proxy server is running")
+ name = flag.String("name", "", "Name to mount the proxy as")
)
r := rt.Init()
@@ -47,8 +48,34 @@
publisher.AddName(*name)
}
+ if len(*healthzAddr) != 0 {
+ go startHealthzServer(*healthzAddr)
+ }
+
http.Handle("/", proxy)
if err = http.ListenAndServe(*httpAddr, nil); err != nil {
vlog.Fatal(err)
}
}
+
+// healthzHandler implements net/http.Handler
+type healthzHandler struct{}
+
+func (healthzHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+ w.Write([]byte("ok"))
+}
+
+// startHealthzServer starts a HTTP server that simply returns "ok" to every
+// request. This is needed to let the load balancer know that the proxy server
+// is running.
+func startHealthzServer(addr string) {
+ s := http.Server{
+ Addr: addr,
+ Handler: healthzHandler{},
+ ReadTimeout: 10 * time.Second,
+ WriteTimeout: 10 * time.Second,
+ }
+ if err := s.ListenAndServe(); err != nil {
+ vlog.Fatal(err)
+ }
+}
