From 82324a7795d2802793c62600b36cced0d10d20fd Mon Sep 17 00:00:00 2001
From: Tomofumi Hayashi <tohayash@redhat.com>
Date: Mon, 24 Jul 2023 20:20:16 +0900
Subject: [PATCH] This change introduces wait to generate config until API is
 ready

---
 cmd/multus-daemon/main.go | 17 +++++++++++++++++
 pkg/server/server.go      |  2 +-
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/cmd/multus-daemon/main.go b/cmd/multus-daemon/main.go
index b65e6189a..be2c02988 100644
--- a/cmd/multus-daemon/main.go
+++ b/cmd/multus-daemon/main.go
@@ -25,6 +25,7 @@ import (
 	"os"
 	"os/user"
 	"path/filepath"
+	"time"
 
 	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	utilwait "k8s.io/apimachinery/pkg/util/wait"
@@ -74,6 +75,12 @@ func main() {
 		os.Exit(1)
 	}
 
+	// Wait until daemon ready
+	if waitUntilAPIReady(daemonConf.SocketDir) != nil {
+		logging.Panicf("failed to ready multus-daemon socket: %v", err)
+		os.Exit(1)
+	}
+
 	// Generate multus CNI config from current CNI config
 	if multusConf.MultusConfigFile == "auto" {
 		if multusConf.CNIVersion == "" {
@@ -140,6 +147,16 @@ func main() {
 	// never reached
 }
 
+func waitUntilAPIReady(socketPath string) error {
+	apiReadyPollDuration := 100 * time.Millisecond
+	apiReadyPollTimeout := 1000 * time.Millisecond
+
+	return utilwait.PollImmediate(apiReadyPollDuration, apiReadyPollTimeout, func() (bool, error) {
+		_, err := api.DoCNI(api.GetAPIEndpoint(api.MultusHealthAPIEndpoint), nil, api.SocketPath(socketPath))
+		return err == nil, nil
+	})
+}
+
 func startMultusDaemon(daemonConfig *srv.ControllerNetConf, stopCh chan struct{}, done chan struct{}) error {
 	if user, err := user.Current(); err != nil || user.Uid != "0" {
 		return fmt.Errorf("failed to run multus-daemon with root: %v, now running in uid: %s", err, user.Uid)
diff --git a/pkg/server/server.go b/pkg/server/server.go
index 23da971b3..4eb4e0770 100644
--- a/pkg/server/server.go
+++ b/pkg/server/server.go
@@ -225,7 +225,7 @@ func newCNIServer(rundir string, kubeClient *k8s.ClientInfo, exec invoke.Exec, s
 	// handle for '/healthz'
 	router.HandleFunc(api.MultusHealthAPIEndpoint, promhttp.InstrumentHandlerCounter(s.metrics.requestCounter.MustCurryWith(prometheus.Labels{"handler": api.MultusHealthAPIEndpoint}),
 		http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			if r.Method != http.MethodGet {
+			if r.Method != http.MethodGet && r.Method != http.MethodPost {
 				http.Error(w, fmt.Sprintf("Method not allowed"), http.StatusMethodNotAllowed)
 				return
 			}