Thick plugin should not wait for API readiness on CNI DEL

pkg/server/api/api.go

@@ -104,3 +104,12 @@ func WaitUntilAPIReady(socketPath string) error {
 		return err == nil, nil
 	})
 }
+
+// CheckAPIReadyNow checks API readiness once
+func CheckAPIReadyNow(socketPath string) error {
+	_, err := DoCNI(GetAPIEndpoint(MultusHealthAPIEndpoint), nil, SocketPath(socketPath))
+	if err != nil {
+		return fmt.Errorf("CheckAPIReadyNow: Daemon not reachable over socketfile: %v", err)
+	}
+	return nil
+}

pkg/server/api/shim.go

@@ -40,9 +40,12 @@
 	LogToStderr     bool   `json:"logToStderr,omitempty"`
 }
 
+// Define a type for API readiness check functions
+type APIReadyCheckFunc func(string) error
+
 // CmdAdd implements the CNI spec ADD command handler
 func CmdAdd(args *skel.CmdArgs) error {
-	response, cniVersion, err := postRequest(args)
+	response, cniVersion, err := postRequest(args, WaitUntilAPIReady)
 	if err != nil {
 		return logging.Errorf("CmdAdd (shim): %v", err)
 	}
@@ -53,7 +56,7 @@
 
 // CmdCheck implements the CNI spec CHECK command handler
 func CmdCheck(args *skel.CmdArgs) error {
-	_, _, err := postRequest(args)
+	_, _, err := postRequest(args, WaitUntilAPIReady)
 	if err != nil {
 		return logging.Errorf("CmdCheck (shim): %v", err)
 	}
@@ -63,22 +66,22 @@
 
 // CmdDel implements the CNI spec DEL command handler
 func CmdDel(args *skel.CmdArgs) error {
-	_, _, err := postRequest(args)
+	_, _, err := postRequest(args, CheckAPIReadyNow)
 	if err != nil {
 		// No error in DEL (as of CNI spec)
 		logging.Errorf("CmdDel (shim): %v", err)
 	}
 	return nil
 }
 
-func postRequest(args *skel.CmdArgs) (*Response, string, error) {
+func postRequest(args *skel.CmdArgs, readinessCheck APIReadyCheckFunc) (*Response, string, error) {
 	multusShimConfig, err := shimConfig(args.StdinData)
 	if err != nil {
 		return nil, "", fmt.Errorf("invalid CNI configuration passed to multus-shim: %w", err)
 	}
 
-	// check API readiness
-	if err := WaitUntilAPIReady(multusShimConfig.MultusSocketDir); err != nil {
+	// Execute the readiness check as necessary (e.g. don't wait on CNI DEL)
+	if err := readinessCheck(multusShimConfig.MultusSocketDir); err != nil {
 		return nil, multusShimConfig.CNIVersion, err
 	}