Merge pull request #1270 from ordovicia/thin-master-cni-file-flag

thin plugin: Handle `--multus-master-cni-file-name` flag

cmd/thin_entrypoint/main.go

@@ -310,22 +310,32 @@ const multusConfTemplate = `{
 }
 `
 
-func (o *Options) createMultusConfig(prevMasterConfigFileHash []byte) (string, []byte, error) {
-	// find master file from MultusAutoconfigDir
+func (o *Options) getMasterConfigPath() (string, error) {
+	// Master config file is specified
+	if o.MultusMasterCNIFileName != "" {
+		return filepath.Join(o.MultusAutoconfigDir, o.MultusMasterCNIFileName), nil
+	}
+
+	// Pick the alphabetically first config file from MultusAutoconfigDir
 	files, err := libcni.ConfFiles(o.MultusAutoconfigDir, []string{".conf", ".conflist"})
 	if err != nil {
-		return "", nil, fmt.Errorf("cannot find master CNI config in %q: %v", o.MultusAutoconfigDir, err)
+		return "", fmt.Errorf("cannot find master CNI config in %q: %v", o.MultusAutoconfigDir, err)
 	}
 
-	masterConfigPath := ""
 	for _, filename := range files {
 		if !strings.HasPrefix(filepath.Base(filename), "00-multus.conf") {
-			masterConfigPath = filename
-			break
+			return filename, nil
 		}
 	}
-	if masterConfigPath == "" {
-		return "", nil, fmt.Errorf("cannot find valid master CNI config in %q", o.MultusAutoconfigDir)
+
+	// No config file found
+	return "", fmt.Errorf("cannot find valid master CNI config in %q", o.MultusAutoconfigDir)
+}
+
+func (o *Options) createMultusConfig(prevMasterConfigFileHash []byte) (string, []byte, error) {
+	masterConfigPath, err := o.getMasterConfigPath()
+	if err != nil {
+		return "", nil, err
 	}
 
 	masterConfigBytes, masterConfigFileHash, err := getFileAndHash(masterConfigPath)

cmd/thin_entrypoint/main_test.go

@@ -411,4 +411,65 @@ var _ = Describe("thin entrypoint testing", func() {
 		Expect(os.RemoveAll(tmpDir)).To(Succeed())
 	})
 
+	It("Run createMultusConfig(), with options, conflist", func() {
+		// create directory and files
+		tmpDir, err := os.MkdirTemp("", "multus_thin_entrypoint_tmp")
+		Expect(err).NotTo(HaveOccurred())
+
+		multusAutoConfigDir := fmt.Sprintf("%s/auto_conf", tmpDir)
+		cniConfDir := fmt.Sprintf("%s/cni_conf", tmpDir)
+
+		Expect(os.Mkdir(multusAutoConfigDir, 0755)).To(Succeed())
+		Expect(os.Mkdir(cniConfDir, 0755)).To(Succeed())
+
+		// create master CNI config
+		masterCNIConfigFileName := "10-testcni.conf"
+		masterCNIConfig := `
+		{
+			"cniVersion": "1.0.0",
+			"name": "test1",
+			"type": "cnitesttype"
+		}`
+		Expect(os.WriteFile(fmt.Sprintf("%s/%s", multusAutoConfigDir, masterCNIConfigFileName), []byte(masterCNIConfig), 0755)).To(Succeed())
+
+		// create another CNI config
+		anotherCNIConfigFileName := "09-test2cni.conf" // Alphabetically before masterCNIConfigFileName
+		anotherCNIConfig := `
+		{
+			"cniVersion": "1.0.0",
+			"name": "test2",
+			"type": "cnitest2type"
+		}`
+		Expect(os.WriteFile(fmt.Sprintf("%s/%s", multusAutoConfigDir, anotherCNIConfigFileName), []byte(anotherCNIConfig), 0755)).To(Succeed())
+
+		masterConfigPath, masterConfigHash, err := (&Options{
+			MultusAutoconfigDir:      multusAutoConfigDir,
+			MultusMasterCNIFileName:  masterCNIConfigFileName,
+			CNIConfDir:               cniConfDir,
+			MultusKubeConfigFileHost: "/etc/foobar_kubeconfig",
+		}).createMultusConfig(nil)
+		Expect(err).NotTo(HaveOccurred())
+
+		Expect(masterConfigPath).NotTo(Equal(""))
+		Expect(masterConfigHash).NotTo(Equal(""))
+
+		expectedResult :=
+			`{
+    "cniVersion": "1.0.0",
+    "name": "multus-cni-network",
+    "plugins": [ {
+        "type": "multus",
+        "logToStderr": false,
+        "kubeconfig": "/etc/foobar_kubeconfig",
+        "delegates": [
+            {"cniVersion":"1.0.0","name":"test1","type":"cnitesttype"}
+        ]
+    }]
+}
+`
+		conf, err := os.ReadFile(fmt.Sprintf("%s/00-multus.conflist", cniConfDir))
+		Expect(string(conf)).To(Equal(expectedResult))
+
+		Expect(os.RemoveAll(tmpDir)).To(Succeed())
+	})
 })