create multus kubeconfig for incase of non auto flag.

cmd/thin_entrypoint/main.go

@@ -153,12 +153,19 @@ func getFileAndHash(filepath string) ([]byte, []byte, error) {
 	return content, hash.Sum(nil), nil
 }
 
-func (o *Options) createKubeConfig(prevCAHash, prevSATokenHash []byte) ([]byte, []byte, error) {
-	caFileByte, caHash, err := getFileAndHash(serviceAccountCAFile)
+func (o *Options) createKubeConfig(caFilePath, saTokenFilePath string, prevCAHash, prevSATokenHash []byte) ([]byte, []byte, error) {
+	// Use default paths if nil is passed
+	if caFilePath == "" {
+		caFilePath = serviceAccountCAFile
+	}
+	if saTokenFilePath == "" {
+		saTokenFilePath = serviceAccountTokenFile
+	}
+	caFileByte, caHash, err := getFileAndHash(caFilePath)
 	if err != nil {
 		return nil, nil, err
 	}
-	saTokenByte, saTokenHash, err := getFileAndHash(serviceAccountTokenFile)
+	saTokenByte, saTokenHash, err := getFileAndHash(saTokenFilePath)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -582,6 +589,11 @@ func main() {
 	var masterConfigFilePath string
 	// copy user specified multus conf to CNI conf directory
 	if opt.MultusConfFile != "auto" {
+		caHash, saTokenHash, err = opt.createKubeConfig("", "", nil, nil)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "failed to create multus kubeconfig: %v\n", err)
+			return
+		}
 		confFileName := filepath.Base(opt.MultusConfFile)
 		tempConfFileName := fmt.Sprintf("%s.temp", confFileName)
 		if err = cmdutils.CopyFileAtomic(opt.MultusConfFile, opt.CNIConfDir, tempConfFileName, confFileName); err != nil {
@@ -590,7 +602,7 @@ func main() {
 		}
 		fmt.Printf("multus config file %s is copied.\n", opt.MultusConfFile)
 	} else { // auto generate multus config
-		caHash, saTokenHash, err = opt.createKubeConfig(nil, nil)
+		caHash, saTokenHash, err = opt.createKubeConfig("", "", nil, nil)
 		if err != nil {
 			fmt.Fprintf(os.Stderr, "failed to create multus kubeconfig: %v\n", err)
 			return
@@ -608,7 +620,7 @@ func main() {
 		fmt.Printf("Entering watch loop...\n")
 		for {
 			// Check kubeconfig and update if different (i.e. service account updated)
-			caHash, saTokenHash, err = opt.createKubeConfig(caHash, saTokenHash)
+			caHash, saTokenHash, err = opt.createKubeConfig("", "", caHash, saTokenHash)
 			if err != nil {
 				fmt.Fprintf(os.Stderr, "failed to update multus kubeconfig: %v\n", err)
 				return

cmd/thin_entrypoint/main_test.go

@@ -472,4 +472,43 @@ var _ = Describe("thin entrypoint testing", func() {
 
 		Expect(os.RemoveAll(tmpDir)).To(Succeed())
 	})
+
+	It("Run createKubeConfig() with expected environment", func() {
+		// create directory and files
+		tmpDir, err := os.MkdirTemp("", "kubeconfig_test_tmp")
+		Expect(err).NotTo(HaveOccurred())
+
+		cniConfDir := fmt.Sprintf("%s/cni_conf", tmpDir)
+		Expect(os.Mkdir(cniConfDir, 0755)).To(Succeed())
+
+		// Set up the Options struct
+		options := &Options{
+			CNIConfDir:          cniConfDir,
+			MultusCNIConfDir:    "/tmp/multus/net.d",
+		}
+
+		// Create service account CA file and token file with dummy data
+		serviceAccountCAFile := fmt.Sprintf("%s/serviceAccountCAFile", tmpDir)
+		serviceAccountTokenFile := fmt.Sprintf("%s/serviceAccountTokenFile", tmpDir)
+		Expect(os.WriteFile(serviceAccountCAFile, []byte("dummy-ca-content"), 0644)).To(Succeed())
+		Expect(os.WriteFile(serviceAccountTokenFile, []byte("dummy-token-content"), 0644)).To(Succeed())
+
+		// Run the createKubeConfig function
+		caHash, saTokenHash, err := options.createKubeConfig(serviceAccountCAFile, serviceAccountTokenFile, nil, nil)
+		Expect(err).NotTo(HaveOccurred())
+
+		// Verify the hashes are not nil
+		Expect(caHash).NotTo(BeNil())
+		Expect(saTokenHash).NotTo(BeNil())
+
+		// Verify the kubeconfig file was created successfully
+		kubeConfigPath := fmt.Sprintf("%s/multus.d/multus.kubeconfig", options.CNIConfDir)
+		content, err := os.ReadFile(kubeConfigPath)
+		Expect(err).NotTo(HaveOccurred())
+		Expect(content).NotTo(BeEmpty())
+
+		// Cleanup
+		Expect(os.RemoveAll(tmpDir)).To(Succeed())
+	})
+
 })