Add UT for cmd/kubeadm/app/cmd/util/join.go

Signed-off-by: bzsuni <[email protected]>

Author: bzsuni

cmd/kubeadm/app/cmd/util/join_test.go

@@ -0,0 +1,196 @@
+/*
+Copyright 2024 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package util
+
+import (
+	"encoding/base64"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"k8s.io/client-go/tools/clientcmd"
+	clientcmdapi "k8s.io/client-go/tools/clientcmd/api"
+)
+
+type testKubeConfigSpec struct {
+	certificateAuthorityData string
+	certificateAuthorityFile string
+	server                   string
+	clusterName              string
+	contextName              string
+	user                     string
+}
+
+func generateTestKubeConfig(spec testKubeConfigSpec) *clientcmdapi.Config {
+	cluster := clientcmdapi.NewCluster()
+
+	if spec.certificateAuthorityData != "" {
+		decodedData, _ := base64.StdEncoding.DecodeString(spec.certificateAuthorityData)
+		cluster.CertificateAuthorityData = decodedData
+	} else if spec.certificateAuthorityFile != "" {
+		cluster.CertificateAuthority = spec.certificateAuthorityFile
+	}
+
+	cluster.Server = spec.server
+
+	context := clientcmdapi.NewContext()
+	context.Cluster = spec.clusterName
+	context.AuthInfo = spec.user
+
+	return &clientcmdapi.Config{
+		Clusters: map[string]*clientcmdapi.Cluster{
+			spec.clusterName: cluster,
+		},
+		Contexts: map[string]*clientcmdapi.Context{
+			spec.contextName: context,
+		},
+		CurrentContext: spec.contextName,
+	}
+}
+
+func generateValidKubeConfig() *clientcmdapi.Config {
+	return generateTestKubeConfig(testKubeConfigSpec{
+		certificateAuthorityData: "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",
+		server:                   "test-server:6443",
+		clusterName:              "somecluster",
+		contextName:              "test@somecluster",
+		user:                     "test",
+	})
+}
+
+func generateMissingCAKubeConfig() *clientcmdapi.Config {
+	return generateTestKubeConfig(testKubeConfigSpec{
+		server:      "test-server:6443",
+		clusterName: "somecluster",
+		contextName: "test@somecluster",
+		user:        "test",
+	})
+}
+
+func generateInvalidFilePathKubeConfig() *clientcmdapi.Config {
+	return generateTestKubeConfig(testKubeConfigSpec{
+		certificateAuthorityFile: "invalid-file",
+		server:                   "test-server:6443",
+		clusterName:              "somecluster",
+		contextName:              "test@somecluster",
+		user:                     "test",
+	})
+}
+
+func generateInvalidCAKubeConfig() *clientcmdapi.Config {
+	return generateTestKubeConfig(testKubeConfigSpec{
+		certificateAuthorityData: "invalid-data",
+		server:                   "test-server:6443",
+		clusterName:              "somecluster",
+		contextName:              "test@somecluster",
+		user:                     "test",
+	})
+}
+
+func TestGetJoinCommand(t *testing.T) {
+	tests := []struct {
+		name         string
+		kubeConfig   *clientcmdapi.Config
+		expectError  bool
+		errorMessage string
+		token        string
+		expectRes    string
+	}{
+		{
+			name:        "Success with valid kubeconfig and token",
+			kubeConfig:  generateValidKubeConfig(),
+			token:       "test-token",
+			expectError: false,
+			expectRes:   "kubeadm join test-server:6443 --token <value withheld> \\\n\t--discovery-token-ca-cert-hash",
+		},
+		{
+
+			name:         "Error to load kubeconfig",
+			kubeConfig:   nil,
+			token:        "test-token",
+			expectError:  true,
+			errorMessage: "failed to load kubeconfig",
+		},
+
+		{
+			name:         "Error to get default cluster config",
+			kubeConfig:   &clientcmdapi.Config{},
+			token:        "test-token",
+			expectError:  true,
+			errorMessage: "failed to get default cluster config",
+		},
+		{
+			name:         "Error when CA certificate is invalid",
+			kubeConfig:   generateInvalidCAKubeConfig(),
+			expectError:  true,
+			errorMessage: "failed to parse CA certificate from kubeconfig",
+		},
+		{
+			name:         "Error when CA certificate file path is invalid",
+			kubeConfig:   generateInvalidFilePathKubeConfig(),
+			token:        "test-token",
+			expectError:  true,
+			errorMessage: "failed to load CA certificate referenced by kubeconfig",
+		},
+		{
+			name:         "Error when CA certificate is missing",
+			kubeConfig:   generateMissingCAKubeConfig(),
+			token:        "test-token",
+			expectError:  true,
+			errorMessage: "no CA certificates found in kubeconfig",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			tmpDir, err := os.MkdirTemp("", "kubeadm-join-test")
+			if err != nil {
+				t.Fatalf("Unable to create temporary directory: %v", err)
+			}
+			defer func() {
+				err := os.RemoveAll(tmpDir)
+				if err != nil {
+					t.Fatalf("Unable to remove temporary directory: %v", err)
+				}
+			}()
+
+			configFilePath := filepath.Join(tmpDir, "test-config-file")
+			if tt.kubeConfig != nil {
+				configBytes, err := clientcmd.Write(*tt.kubeConfig)
+				if err != nil {
+					t.Fatalf("Failed to clientcmd.Write: %v", err)
+				}
+				err = os.WriteFile(configFilePath, configBytes, 0644)
+				if err != nil {
+					t.Fatalf("Failed to os.WriteFile: %v", err)
+				}
+			}
+
+			res, err := getJoinCommand(configFilePath, tt.token, "", true, true, true)
+
+			if tt.expectError {
+				require.Error(t, err)
+				require.Contains(t, err.Error(), tt.errorMessage)
+			} else {
+				require.NoError(t, err)
+			}
+			require.Contains(t, res, tt.expectRes)
+		})
+	}
+}