Add version checking for --dry-run flag (#145)

Author: mlclmj

main.go

@@ -38,6 +38,9 @@ const (
 	keyPath          = "/tmp/gcloud.json"
 	nsPath           = "/tmp/namespace.json"
 	templateBasePath = "/tmp"
+
+	dryRunFlagPre118  = "--dry-run=true"
+	dryRunFlagDefault = "--dry-run=client"
 )
 
 // default to kubectlCmdName, can be overriden via kubectl-version param
@@ -51,6 +54,7 @@ metadata:
   name: %s
 `
 var invalidNameRegex = regexp.MustCompile(`[^a-z0-9\.\-]+`)
+var dryRunFlag = dryRunFlagDefault
 
 func main() {
 	err := wrapMain()
@@ -225,6 +229,13 @@ func run(c *cli.Context) error {
 		kubectlCmd = fmt.Sprintf("%s.%s", kubectlCmdName, kubectlVersion)
 	}
 
+	// Parse and adjust the dry-run flag if needed
+	var dryRunBuffer bytes.Buffer
+	dryRunRunner := NewBasicRunner("/", []string{}, &dryRunBuffer, &dryRunBuffer)
+	if err := setDryRunFlag(dryRunRunner, &dryRunBuffer); err != nil {
+		return err
+	}
+
 	// Parse variables and secrets
 	vars, err := parseVars(c)
 	if err != nil {
@@ -395,6 +406,52 @@ func parseSkips(c *cli.Context) error {
 	return nil
 }
 
+// setDryRunFlag sets the value of the dry-run flag for the version of kubectl
+// that is being used
+func setDryRunFlag(runner Runner, output io.Reader) error {
+	dryRunFlag = dryRunFlagDefault
+	version, err := getMinorVersion(runner, output)
+	if err != nil {
+		return fmt.Errorf("Error determining which kubectl version is running: %v", err)
+	}
+	// default is the >= 1.18 flag
+	if version < 18 {
+		dryRunFlag = dryRunFlagPre118
+	}
+	return nil
+}
+
+// getMinorVersion fetches and parses the version from kubectl
+func getMinorVersion(runner Runner, output io.Reader) (int64, error) {
+	runner.Run(kubectlCmd, "version", "--client", "-o=json")
+	data, err := ioutil.ReadAll(output)
+	if err != nil {
+		return 0, fmt.Errorf("Error reading kubectl version: %v", err)
+	}
+
+	var versionOutput struct {
+		ClientVersion struct {
+			Minor string
+		}
+	}
+
+	err = json.Unmarshal(data, &versionOutput)
+	if err != nil {
+		return 0, fmt.Errorf("Error reading kubectl version: %v", err)
+	}
+
+	versionString, err := strings.Replace(versionOutput.ClientVersion.Minor, "+", "", 1), nil
+	if err != nil {
+		return 0, fmt.Errorf("Error removing extra '+' from version string: %v", err)
+	}
+
+	versionInt, err := strconv.ParseInt(versionString, 10, 64)
+	if err != nil {
+		return 0, fmt.Errorf("Couldn't parse minor version from string: %v", err)
+	}
+	return versionInt, nil
+}
+
 // parseVars parses vars (in JSON) and returns a map
 func parseVars(c *cli.Context) (map[string]interface{}, error) {
 	// Parse variables.
@@ -758,7 +815,7 @@ func applyArgs(dryrun bool, file string) []string {
 	}
 
 	if dryrun {
-		args = append(args, "--dry-run=client")
+		args = append(args, dryRunFlag)
 	}
 
 	args = append(args, "--filename")

main_test.go

@@ -678,3 +678,163 @@ func TestTokenParamPrecedence(t *testing.T) {
 		})
 	}
 }
+
+func TestSetDryRunFlag(t *testing.T) {
+	tests := []struct {
+		name string
+		versionCommandOutput string
+		explicitVersion string
+
+		expectedFlag string
+	}{
+		{
+			name: "default-1.17",
+			versionCommandOutput: `{
+				"clientVersion": {
+					"major": "1",
+					"minor": "17+",
+					"gitVersion": "v1.17.17-dispatcher",
+					"gitCommit": "a39a896b5018d0c800124a36757433c660fd0880",
+					"gitTreeState": "clean",
+					"buildDate": "2021-01-28T21:47:26Z",
+					"goVersion": "go1.13.9",
+					"compiler": "gc",
+					"platform": "linux/amd64"
+				}
+			}`,
+			explicitVersion: "",
+			expectedFlag: dryRunFlagPre118,
+		},
+		{
+			name: "kubectl-1.15",
+			versionCommandOutput: `{
+				"clientVersion": {
+					"major": "1",
+					"minor": "15",
+					"gitVersion": "v1.15.12",
+					"gitCommit": "e2a822d9f3c2fdb5c9bfbe64313cf9f657f0a725",
+					"gitTreeState": "clean",
+					"buildDate": "2020-05-06T05:17:59Z",
+					"goVersion": "go1.12.17",
+					"compiler": "gc",
+					"platform": "linux/amd64"
+				}
+			}`,
+			explicitVersion: "1.15",
+			expectedFlag: dryRunFlagPre118,
+		},
+		{
+			name: "kubectl-1.16",
+			versionCommandOutput: `{
+				"clientVersion": {
+					"major": "1",
+					"minor": "16",
+					"gitVersion": "v1.16.15",
+					"gitCommit": "2adc8d7091e89b6e3ca8d048140618ec89b39369",
+					"gitTreeState": "clean",
+					"buildDate": "2020-09-02T11:40:00Z",
+					"goVersion": "go1.13.15",
+					"compiler": "gc",
+					"platform": "linux/amd64"
+				}
+			}`,
+			explicitVersion: "1.16",
+			expectedFlag: dryRunFlagPre118,
+		},
+		{
+			name: "kubectl-1.17",
+			versionCommandOutput: `{
+				"clientVersion": {
+					"major": "1",
+					"minor": "17",
+					"gitVersion": "v1.17.17",
+					"gitCommit": "f3abc15296f3a3f54e4ee42e830c61047b13895f",
+					"gitTreeState": "clean",
+					"buildDate": "2021-01-13T13:21:12Z",
+					"goVersion": "go1.13.15",
+					"compiler": "gc",
+					"platform": "linux/amd64"
+				}
+			}`,
+			explicitVersion: "1.17",
+			expectedFlag: dryRunFlagPre118,
+		},
+		{
+			name: "kubectl-1.18",
+			versionCommandOutput: `{
+				"clientVersion": {
+					"major": "1",
+					"minor": "18",
+					"gitVersion": "v1.18.15",
+					"gitCommit": "73dd5c840662bb066a146d0871216333181f4b64",
+					"gitTreeState": "clean",
+					"buildDate": "2021-01-13T13:22:41Z",
+					"goVersion": "go1.13.15",
+					"compiler": "gc",
+					"platform": "linux/amd64"
+				}
+			}`,
+			explicitVersion: "1.18",
+			expectedFlag: dryRunFlagDefault,
+		},
+		{
+			name: "kubectl-1.19",
+			versionCommandOutput: `{
+				"clientVersion": {
+					"major": "1",
+					"minor": "19",
+					"gitVersion": "v1.19.7",
+					"gitCommit": "1dd5338295409edcfff11505e7bb246f0d325d15",
+					"gitTreeState": "clean",
+					"buildDate": "2021-01-13T13:23:52Z",
+					"goVersion": "go1.15.5",
+					"compiler": "gc",
+					"platform": "linux/amd64"
+				}
+			}`,
+			explicitVersion: "1.19",
+			expectedFlag: dryRunFlagDefault,
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			os.Clearenv()
+
+			os.Setenv("PLUGIN_KUBECTL_VERSION", test.explicitVersion)
+
+			err := (&cli.App{
+				Flags: getAppFlags(),
+				Action: func(ctx *cli.Context) error {
+					// setup
+
+					// copied from lines 227-230 of main.go
+					kubectlVersion := ctx.String("kubectl-version")
+					if kubectlVersion != "" {
+						kubectlCmd = fmt.Sprintf("%s.%s", kubectlCmdName, kubectlVersion)
+					}
+
+					buf := bytes.NewBufferString(test.versionCommandOutput)
+					testRunner := new(MockedRunner)
+					if test.explicitVersion != "" {
+						testRunner.On("Run", []string{fmt.Sprintf("kubectl.%s", test.explicitVersion), "version", "--client", "-o=json"}).Return(nil)
+					} else {
+						testRunner.On("Run", []string{"kubectl", "version", "--client", "-o=json"}).Return(nil)
+					}
+
+					// Run
+					setDryRunFlag(testRunner, buf)
+
+					// Check
+					if dryRunFlag != test.expectedFlag {
+						t.Fatalf("expected: %s, got: %s", test.expectedFlag, dryRunFlag)
+					}
+					return nil
+				},
+			}).Run([]string{"run"})
+
+			if err != nil {
+				t.Fatalf("unepected err: %v", err)
+			}
+		})
+	}
+}