bugfix: do not send pool-scoped resource list/watch request to pool-c…

…oordinator (#1134)

Signed-off-by: Congrool <chpzhangyifei@zju.edu.cn>

Signed-off-by: Congrool <chpzhangyifei@zju.edu.cn>

pkg/yurthub/proxy/proxy.go

@@ -37,6 +37,7 @@ import (
 	"github.com/openyurtio/openyurt/pkg/yurthub/cachemanager"
 	"github.com/openyurtio/openyurt/pkg/yurthub/healthchecker"
 	"github.com/openyurtio/openyurt/pkg/yurthub/poolcoordinator"
+	coordinatorconstants "github.com/openyurtio/openyurt/pkg/yurthub/poolcoordinator/constants"
 	"github.com/openyurtio/openyurt/pkg/yurthub/proxy/local"
 	"github.com/openyurtio/openyurt/pkg/yurthub/proxy/pool"
 	"github.com/openyurtio/openyurt/pkg/yurthub/proxy/remote"
@@ -217,6 +218,15 @@ func (p *yurtReverseProxy) eventHandler(rw http.ResponseWriter, req *http.Reques
 }
 
 func (p *yurtReverseProxy) poolScopedResouceHandler(rw http.ResponseWriter, req *http.Request) {
+	agent, ok := hubutil.ClientComponentFrom(req.Context())
+	if ok && agent == coordinatorconstants.DefaultPoolScopedUserAgent {
+		// list/watch request from leader-yurthub
+		// It should always be proxied to cloud APIServer to get latest resource, which will
+		// be cached into pool cache.
+		p.loadBalancer.ServeHTTP(rw, req)
+		return
+	}
+
 	if p.isCoordinatorReady() && p.poolProxy != nil {
 		p.poolProxy.ServeHTTP(rw, req)
 	} else if p.cloudHealthChecker.IsHealthy() {

pkg/yurthub/proxy/remote/loadbalancer.go

@@ -194,7 +194,10 @@ func (lb *loadBalancer) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 		return
 	}
 	klog.V(3).Infof("picked backend %s by %s for request %s", rp.Name(), lb.algo.Name(), hubutil.ReqString(req))
-	if util.IsPoolScopedResouceListWatchRequest(req) {
+	// If pool-scoped resource request is from leader-yurthub, it should always be sent to the cloud APIServer.
+	// Thus we do not need to start a check routine for it. But for other requests, we need to periodically check
+	// the pool-coordinator status, and switch the traffic to pool-coordinator if it is ready.
+	if util.IsPoolScopedResouceListWatchRequest(req) && !isRequestFromLeaderYurthub(req) {
 		// We get here possibly because the pool-coordinator is not ready.
 		// We should cancel the watch request when pool-coordinator becomes ready.
 		klog.Infof("pool-coordinator is not ready, we use cloud APIServer to temporarily handle the req: %s", hubutil.ReqString(req))
@@ -420,3 +423,12 @@ func isRequestOfNodeAndPod(reqCtx context.Context) bool {
 	return (reqInfo.Resource == "nodes" && reqInfo.APIGroup == "" && reqInfo.APIVersion == "v1") ||
 		(reqInfo.Resource == "pods" && reqInfo.APIGroup == "" && reqInfo.APIVersion == "v1")
 }
+
+func isRequestFromLeaderYurthub(req *http.Request) bool {
+	ctx := req.Context()
+	agent, ok := hubutil.ClientComponentFrom(ctx)
+	if !ok {
+		return false
+	}
+	return agent == coordinatorconstants.DefaultPoolScopedUserAgent
+}