Merge pull request #61601 from neolit123/test-join

Automatic merge from submit-queue (batch tested with PRs 61601, 62881, 63159). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

kubeadm: add test coverage to join.go

**What this PR does / why we need it**:
Add test coverage to `join.go`.

A separate commit exports the function `ValidateJoinCommandLine()` from `join.go` so that testing this file is more flexible.

Test coverage is at 76%. One untested part is successfully running `Join.Run()` without errors, but that requires a valid HTTPS API server running and a valid config. i got this partially working but gave up because i faced some cert / config blockers. suggestions on how to get that to work easily are welcome.

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:

NONE

**Special notes for your reviewer**:

NONE

**Release note**:

```release-note
NONE
```

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.go

@@ -115,21 +115,7 @@ func NewCmdJoin(out io.Writer) *cobra.Command {
 		Short: "Run this on any machine you wish to join an existing cluster",
 		Long:  joinLongDescription,
 		Run: func(cmd *cobra.Command, args []string) {
-			cfg.DiscoveryTokenAPIServers = args
-
-			var err error
-			if cfg.FeatureGates, err = features.NewFeatureGate(&features.InitFeatureGates, featureGatesString); err != nil {
-				kubeadmutil.CheckErr(err)
-			}
-
-			legacyscheme.Scheme.Default(cfg)
-			internalcfg := &kubeadmapi.NodeConfiguration{}
-			legacyscheme.Scheme.Convert(cfg, internalcfg, nil)
-
-			ignorePreflightErrorsSet, err := validation.ValidateIgnorePreflightErrors(ignorePreflightErrors, skipPreFlight)
-			kubeadmutil.CheckErr(err)
-
-			j, err := NewJoin(cfgPath, args, internalcfg, ignorePreflightErrorsSet)
+			j, err := NewValidJoin(cfg, args, skipPreFlight, cfgPath, featureGatesString, ignorePreflightErrors)
 			kubeadmutil.CheckErr(err)
 			kubeadmutil.CheckErr(j.Validate(cmd))
 			kubeadmutil.CheckErr(j.Run(out))
@@ -142,6 +128,27 @@ func NewCmdJoin(out io.Writer) *cobra.Command {
 	return cmd
 }
 
+// NewValidJoin validates the command line that are passed to the cobra command
+func NewValidJoin(cfg *kubeadmapiext.NodeConfiguration, args []string, skipPreFlight bool, cfgPath, featureGatesString string, ignorePreflightErrors []string) (*Join, error) {
+	cfg.DiscoveryTokenAPIServers = args
+
+	var err error
+	if cfg.FeatureGates, err = features.NewFeatureGate(&features.InitFeatureGates, featureGatesString); err != nil {
+		return nil, err
+	}
+
+	legacyscheme.Scheme.Default(cfg)
+	internalcfg := &kubeadmapi.NodeConfiguration{}
+	legacyscheme.Scheme.Convert(cfg, internalcfg, nil)
+
+	ignorePreflightErrorsSet, err := validation.ValidateIgnorePreflightErrors(ignorePreflightErrors, skipPreFlight)
+	if err != nil {
+		return nil, err
+	}
+
+	return NewJoin(cfgPath, args, internalcfg, ignorePreflightErrorsSet)
+}
+
 // AddJoinConfigFlags adds join flags bound to the config to the specified flagset
 func AddJoinConfigFlags(flagSet *flag.FlagSet, cfg *kubeadmapiext.NodeConfiguration, featureGatesString *string) {
 	flagSet.StringVar(

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)
+		}
+	}
+}