kubeadm: add test coverage to join.go

Included tests:
- TestNewValidJoin

cmd/kubeadm/app/cmd/BUILD

@@ -81,16 +81,19 @@ go_library(
 go_test(
     name = "go_default_test",
     srcs = [
+        "join_test.go",
         "reset_test.go",
         "token_test.go",
         "version_test.go",
     ],
     embed = [":go_default_library"],
     deps = [
+        "//cmd/kubeadm/app/apis/kubeadm:go_default_library",
         "//cmd/kubeadm/app/apis/kubeadm/v1alpha1:go_default_library",
         "//cmd/kubeadm/app/apis/kubeadm/validation:go_default_library",
         "//cmd/kubeadm/app/constants:go_default_library",
         "//cmd/kubeadm/app/preflight:go_default_library",
+        "//pkg/api/legacyscheme:go_default_library",
         "//vendor/github.com/ghodss/yaml:go_default_library",
         "//vendor/k8s.io/api/core/v1:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/api/errors:go_default_library",

cmd/kubeadm/app/cmd/join_test.go

@@ -0,0 +1,187 @@
+/*
+Copyright 2018 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 cmd
+
+import (
+	"bytes"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm"
+	kubeadmapiext "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/v1alpha1"
+	"k8s.io/kubernetes/pkg/api/legacyscheme"
+)
+
+const (
+	testConfig = `apiVersion: v1
+clusters:
+- cluster:
+    certificate-authority-data:
+    server: localhost:9008
+  name: prod
+contexts:
+- context:
+    cluster: prod
+    namespace: default
+    user: default-service-account
+  name: default
+current-context: default
+kind: Config
+preferences: {}
+users:
+- name: kubernetes-admin
+  user:
+    client-certificate-data:
+    client-key-data:
+`
+)
+
+func TestNewValidJoin(t *testing.T) {
+	// create temp directory
+	tmpDir, err := ioutil.TempDir("", "kubeadm-join-test")
+	if err != nil {
+		t.Errorf("Unable to create temporary directory: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	// create config file
+	configFilePath := filepath.Join(tmpDir, "test-config-file")
+	cfgFile, err := os.Create(configFilePath)
+	if err != nil {
+		t.Errorf("Unable to create file %q: %v", configFilePath, err)
+	}
+	defer cfgFile.Close()
+
+	testCases := []struct {
+		name                  string
+		args                  []string
+		skipPreFlight         bool
+		cfgPath               string
+		configToWrite         string
+		featureGatesString    string
+		ignorePreflightErrors []string
+		testJoinValidate      bool
+		testJoinRun           bool
+		cmdPersistentFlags    map[string]string
+		nodeConfig            *kubeadm.NodeConfiguration
+		expectedError         bool
+	}{
+		{
+			name:          "invalid: missing config file",
+			skipPreFlight: true,
+			cfgPath:       "missing-path-to-a-config",
+			expectedError: true,
+		},
+		{
+			name:          "invalid: incorrect config file",
+			skipPreFlight: true,
+			cfgPath:       configFilePath,
+			configToWrite: "bad-config-contents",
+			expectedError: true,
+		},
+		{
+			name:          "invalid: fail at preflight.RunJoinNodeChecks()",
+			skipPreFlight: false,
+			cfgPath:       configFilePath,
+			configToWrite: testConfig,
+			expectedError: true,
+		},
+		{
+			name:                  "invalid: incorrect ignorePreflight argument",
+			skipPreFlight:         true,
+			cfgPath:               configFilePath,
+			configToWrite:         testConfig,
+			ignorePreflightErrors: []string{"some-unsupported-preflight-arg"},
+			expectedError:         true,
+		},
+		{
+			name:               "invalid: incorrect featureGatesString",
+			featureGatesString: "bad-feature-gate-string",
+			expectedError:      true,
+		},
+		{
+			name:             "invalid: fail Join.Validate() with wrong flags",
+			skipPreFlight:    true,
+			cfgPath:          configFilePath,
+			configToWrite:    testConfig,
+			testJoinValidate: true,
+			cmdPersistentFlags: map[string]string{
+				"config":    "some-config",
+				"node-name": "some-node-name",
+			},
+			expectedError: true,
+		},
+		{
+			name:             "invalid: fail Join.Validate() with wrong node configuration",
+			skipPreFlight:    true,
+			cfgPath:          configFilePath,
+			configToWrite:    testConfig,
+			testJoinValidate: true,
+			expectedError:    true,
+		},
+		{
+			name:          "invalid: fail Join.Run() with invalid node config",
+			skipPreFlight: true,
+			cfgPath:       configFilePath,
+			configToWrite: testConfig,
+			testJoinRun:   true,
+			expectedError: true,
+		},
+	}
+
+	var out bytes.Buffer
+	cfg := &kubeadmapiext.NodeConfiguration{}
+	legacyscheme.Scheme.Default(cfg)
+
+	errorFormat := "Test case %q: NewValidJoin expected error: %v, saw: %v, error: %v"
+
+	for _, tc := range testCases {
+		if _, err = cfgFile.WriteString(tc.configToWrite); err != nil {
+			t.Fatalf("Unable to write file %q: %v", tc.cfgPath, err)
+		}
+
+		join, err := NewValidJoin(cfg, tc.args, tc.skipPreFlight, tc.cfgPath, tc.featureGatesString, tc.ignorePreflightErrors)
+		cmd := NewCmdJoin(&out)
+
+		if tc.cmdPersistentFlags != nil {
+			for key, value := range tc.cmdPersistentFlags {
+				cmd.PersistentFlags().Set(key, value)
+			}
+		}
+		if tc.nodeConfig != nil {
+			join.cfg = tc.nodeConfig
+		}
+
+		// test Join.Run()
+		if err == nil && tc.testJoinRun {
+			err = join.Run(&out)
+			if (err != nil) != tc.expectedError {
+				t.Fatalf(errorFormat, tc.name, tc.expectedError, (err != nil), err)
+			}
+			// test Join.Validate()
+		} else if err == nil && tc.testJoinValidate {
+			if err = join.Validate(cmd); (err != nil) != tc.expectedError {
+				t.Fatalf(errorFormat, tc.name, tc.expectedError, (err != nil), err)
+			}
+			// check error for NewValidJoin()
+		} else if (err != nil) != tc.expectedError {
+			t.Fatalf(errorFormat, tc.name, tc.expectedError, (err != nil), err)
+		}
+	}
+}