cli: Introduce an upgrade command

cli/cmd/inject.go

@@ -102,11 +102,16 @@ sub-folders, or coming from stdin.`,
 		},
 	}
 
-	cmd.PersistentFlags().AddFlagSet(options.proxyConfigOptions.flagSet(pflag.ExitOnError))
-	cmd.PersistentFlags().BoolVar(
+	flags := options.proxyConfigOptions.flagSet(pflag.ExitOnError)
+	flags.BoolVar(
 		&options.disableIdentity, "disable-identity", options.disableIdentity,
 		"Disables resources from participating in TLS identity",
 	)
+	flags.BoolVar(
+		&options.ignoreCluster, "ignore-cluster", options.ignoreCluster,
+		"Ignore the current Kubernetes cluster when checking for existing cluster configuration (default false)",
+	)
+	cmd.PersistentFlags().AddFlagSet(flags)
 
 	return cmd
 }
@@ -295,7 +300,7 @@ func (options *injectOptions) fetchConfigsOrDefault() (*config.All, error) {
 // overrideConfigs uses command-line overrides to update the provided configs.
 // the overrideAnnotations map keeps track of which configs are overridden, by
 // storing the corresponding annotations and values.
-func (options *injectOptions) overrideConfigs(configs *config.All, overrideAnnotations map[string]string) {
+func (options *proxyConfigOptions) overrideConfigs(configs *config.All, overrideAnnotations map[string]string) {
 	if options.linkerdVersion != "" {
 		configs.Global.Version = options.linkerdVersion
 	}

cli/cmd/inject_test.go

@@ -54,7 +54,7 @@ func testUninjectAndInject(t *testing.T, tc testCase) {
 }
 
 func testInstallConfig() *pb.All {
-	_, c, err := testInstallOptions().validateAndBuild()
+	_, c, err := testInstallOptions().validateAndBuild(nil)
 	if err != nil {
 		log.Fatalf("test install options must be valid: %s", err)
 	}

cli/cmd/install.go

@@ -208,24 +208,50 @@ func newCmdInstall() *cobra.Command {
 		Short: "Output Kubernetes configs to install Linkerd",
 		Long:  "Output Kubernetes configs to install Linkerd.",
 		RunE: func(cmd *cobra.Command, args []string) error {
-			options.recordFlags(flags)
+			if !options.ignoreCluster {
+				exitIfClusterExists()
+			}
 
-			values, configs, err := options.validateAndBuild()
+			values, configs, err := options.validateAndBuild(flags)
 			if err != nil {
 				return err
 			}
+
 			return values.render(os.Stdout, configs)
 		},
 	}
 
 	cmd.PersistentFlags().AddFlagSet(flags)
 
-	// Issuer flags are currently only supported on the initial install.
-	cmd.PersistentFlags().AddFlagSet(options.issuerFlagSet(pflag.ExitOnError))
+	// Some flags are not available during upgrade, etc.
+	cmd.PersistentFlags().AddFlagSet(options.installOnlyFlagSet(pflag.ExitOnError))
 
 	return cmd
 }
 
+func (options *installOptions) validateAndBuild(flags *pflag.FlagSet) (*installValues, *pb.All, error) {
+	if err := options.validate(); err != nil {
+		return nil, nil, err
+	}
+	options.recordFlags(flags)
+
+	identityValues, err := options.identityOptions.validateAndBuild()
+	if err != nil {
+		return nil, nil, err
+	}
+
+	configs := options.configs(identityValues.toIdentityContext())
+
+	values, err := options.buildValuesWithoutIdentity(configs)
+	if err != nil {
+		return nil, nil, err
+	}
+	values.Identity = identityValues
+
+	return values, configs, nil
+}
+
+// flagSet returns flags usable during install or upgrade.
 func (options *installOptions) flagSet(e pflag.ErrorHandling) *pflag.FlagSet {
 	flags := pflag.NewFlagSet("install", e)
 
@@ -259,12 +285,17 @@ func (options *installOptions) flagSet(e pflag.ErrorHandling) *pflag.FlagSet {
 		&options.identityOptions.issuanceLifetime, "identity-issuance-lifetime", options.identityOptions.issuanceLifetime,
 		"The amount of time for which the Identity issuer should certify identity",
 	)
+	flags.DurationVar(
+		&options.identityOptions.clockSkewAllowance, "identity-clock-skew-allowance", options.identityOptions.clockSkewAllowance,
+		"The amount of time to allow for clock skew within a Linkerd cluster",
+	)
 
 	return flags
 }
 
-func (options *installOptions) issuerFlagSet(e pflag.ErrorHandling) *pflag.FlagSet {
-	flags := pflag.NewFlagSet("issuer", e)
+// installOnlyFlagSet includes flags that are only accessible at install-time and not at upgrade-time.
+func (options *installOptions) installOnlyFlagSet(e pflag.ErrorHandling) *pflag.FlagSet {
+	flags := pflag.NewFlagSet("install", e)
 
 	flags.StringVar(
 		&options.identityOptions.trustDomain, "identity-trust-domain", options.identityOptions.trustDomain,
@@ -282,13 +313,10 @@ func (options *installOptions) issuerFlagSet(e pflag.ErrorHandling) *pflag.FlagS
 		&options.identityOptions.keyPEMFile, "identity-issuer-key-file", options.identityOptions.keyPEMFile,
 		"A path to a PEM-encoded file containing the Linkerd Identity issuer private key (generated by default)",
 	)
-	flags.DurationVar(
-		&options.identityOptions.clockSkewAllowance, "identity-clock-skew-allowance", options.identityOptions.clockSkewAllowance,
-		"The amount of time to allow for clock skew within a Linkerd cluster",
-	)
-	flags.DurationVar(
-		&options.identityOptions.issuanceLifetime, "identity-issuance-lifetime", options.identityOptions.issuanceLifetime,
-		"The amount of time for which the Identity issuer should certify identity",
+
+	flags.BoolVar(
+		&options.ignoreCluster, "ignore-cluster", options.ignoreCluster,
+		"Ignore the current Kubernetes cluster when checking for existing cluster configuration (default false)",
 	)
 
 	return flags
@@ -331,26 +359,6 @@ func (options *installOptions) validate() error {
 		return errors.New("--proxy-log-level must not be empty")
 	}
 
-	if !options.ignoreCluster {
-		exists, err := linkerdConfigAlreadyExistsInCluster()
-		if err != nil {
-			fmt.Fprintln(os.Stderr, "Unable to connect to a Kubernetes cluster to check for configuration. If this expected, use the --ignore-cluster flag.")
-			os.Exit(1)
-		}
-		if exists {
-			fmt.Fprintln(os.Stderr, "You are already running a control plane. If you would like to ignore its configuration, use the --ignore-cluster flag.")
-			os.Exit(1)
-		}
-	}
-
-	return nil
-}
-
-func (options *installOptions) validateAndBuild() (*installValues, *pb.All, error) {
-	if err := options.validate(); err != nil {
-		return nil, nil, err
-	}
-
 	if options.highAvailability {
 		if options.controllerReplicas == defaultControllerReplicas {
 			options.controllerReplicas = defaultHAControllerReplicas
@@ -366,16 +374,14 @@ func (options *installOptions) validateAndBuild() (*installValues, *pb.All, erro
 	}
 
 	options.identityOptions.replicas = options.controllerReplicas
-	identityValues, err := options.identityOptions.validateAndBuild()
-	if err != nil {
-		return nil, nil, err
-	}
 
-	configs := options.configs(identityValues.toIdentityContext())
+	return nil
+}
 
+func (options *installOptions) buildValuesWithoutIdentity(configs *pb.All) (*installValues, error) {
 	globalJSON, proxyJSON, installJSON, err := config.ToJSON(configs)
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 
 	values := &installValues{
@@ -410,8 +416,6 @@ func (options *installOptions) validateAndBuild() (*installValues, *pb.All, erro
 			Proxy:   proxyJSON,
 			Install: installJSON,
 		},
-
-		Identity: identityValues,
 	}
 
 	if options.highAvailability {
@@ -438,7 +442,7 @@ func (options *installOptions) validateAndBuild() (*installValues, *pb.All, erro
 		}
 	}
 
-	return values, configs, nil
+	return values, nil
 }
 
 func toPromLogLevel(level string) string {
@@ -622,42 +626,48 @@ func (options *installOptions) proxyConfig() *pb.Proxy {
 	}
 }
 
-// linkerdConfigAlreadyExistsInCluster checks the kubernetes API to determine
-// whether a config exists.
+// exitIfClusterExists checks the kubernetes API to determine
+// whether a config exists and exits if it does exist or if an error is
+// encountered.
 //
 // This bypasses the public API so that public API errors cannot cause us to
 // misdiagnose a controller error to indicate that no control plane exists.
-//
-// If we cannot determine whether the configuration exists, an error is returned.
-func linkerdConfigAlreadyExistsInCluster() (bool, error) {
+func exitIfClusterExists() {
 	api, err := k8s.NewAPI(kubeconfigPath, kubeContext)
 	if err != nil {
-		return false, err
+		fmt.Fprintln(os.Stderr, "Unable to build a Kubernetes client to check for configuration. If this expected, use the --ignore-cluster flag.")
+		fmt.Fprintf(os.Stderr, "Error: %s\n", err)
+		os.Exit(1)
 	}
 
 	k, err := kubernetes.NewForConfig(api.Config)
 	if err != nil {
-		return false, err
+		fmt.Fprintln(os.Stderr, "Unable to build a Kubernetes client to check for configuration. If this expected, use the --ignore-cluster flag.")
+		fmt.Fprintf(os.Stderr, "Error: %s\n", err)
+		os.Exit(1)
 	}
 
 	c := k.CoreV1().ConfigMaps(controlPlaneNamespace)
 	if _, err = c.Get(k8s.ConfigConfigMapName, metav1.GetOptions{}); err != nil {
 		if kerrors.IsNotFound(err) {
-			return false, nil
+			return
 		}
 
-		return false, err
+		fmt.Fprintln(os.Stderr, "Unable to build a Kubernetes client to check for configuration. If this expected, use the --ignore-cluster flag.")
+		fmt.Fprintf(os.Stderr, "Error: %s\n", err)
+		os.Exit(1)
 	}
 
-	return true, nil
+	fmt.Fprintln(os.Stderr, "Linkerd has already been installed on your cluster in the linkerd namespace. Please run upgrade if you'd like to update this installation. Otherwise, use the --ignore-cluster flag.")
+	os.Exit(1)
 }
 
 func (idopts *installIdentityOptions) validate() error {
 	if idopts == nil {
 		return nil
 	}
 
-	if idopts.trustDomain == "" {
+	if idopts.trustDomain != "" {
 		if errs := validation.IsDNS1123Subdomain(idopts.trustDomain); len(errs) > 0 {
 			return fmt.Errorf("invalid trust domain '%s': %s", idopts.trustDomain, errs[0])
 		}

cli/cmd/install_test.go

@@ -11,7 +11,7 @@ import (
 
 func TestRender(t *testing.T) {
 	defaultOptions := testInstallOptions()
-	defaultValues, defaultConfig, err := defaultOptions.validateAndBuild()
+	defaultValues, defaultConfig, err := defaultOptions.validateAndBuild(nil)
 	if err != nil {
 		t.Fatalf("Unexpected error validating options: %v", err)
 	}
@@ -53,7 +53,7 @@ func TestRender(t *testing.T) {
 	haOptions := testInstallOptions()
 	haOptions.recordedFlags = []*config.Install_Flag{{Name: "ha", Value: "true"}}
 	haOptions.highAvailability = true
-	haValues, haConfig, _ := haOptions.validateAndBuild()
+	haValues, haConfig, _ := haOptions.validateAndBuild(nil)
 
 	haWithOverridesOptions := testInstallOptions()
 	haWithOverridesOptions.recordedFlags = []*config.Install_Flag{
@@ -66,12 +66,12 @@ func TestRender(t *testing.T) {
 	haWithOverridesOptions.controllerReplicas = 2
 	haWithOverridesOptions.proxyCPURequest = "400m"
 	haWithOverridesOptions.proxyMemoryRequest = "300Mi"
-	haWithOverridesValues, haWithOverridesConfig, _ := haWithOverridesOptions.validateAndBuild()
+	haWithOverridesValues, haWithOverridesConfig, _ := haWithOverridesOptions.validateAndBuild(nil)
 
 	noInitContainerOptions := testInstallOptions()
 	noInitContainerOptions.recordedFlags = []*config.Install_Flag{{Name: "linkerd-cni-enabled", Value: "true"}}
 	noInitContainerOptions.noInitContainer = true
-	noInitContainerValues, noInitContainerConfig, _ := noInitContainerOptions.validateAndBuild()
+	noInitContainerValues, noInitContainerConfig, _ := noInitContainerOptions.validateAndBuild(nil)
 
 	noInitContainerWithProxyAutoInjectOptions := testInstallOptions()
 	noInitContainerWithProxyAutoInjectOptions.recordedFlags = []*config.Install_Flag{
@@ -80,7 +80,7 @@ func TestRender(t *testing.T) {
 	}
 	noInitContainerWithProxyAutoInjectOptions.noInitContainer = true
 	noInitContainerWithProxyAutoInjectOptions.proxyAutoInject = true
-	noInitContainerWithProxyAutoInjectValues, noInitContainerWithProxyAutoInjectConfig, _ := noInitContainerWithProxyAutoInjectOptions.validateAndBuild()
+	noInitContainerWithProxyAutoInjectValues, noInitContainerWithProxyAutoInjectConfig, _ := noInitContainerWithProxyAutoInjectOptions.validateAndBuild(nil)
 
 	testCases := []struct {
 		values         *installValues

cli/cmd/root.go

@@ -112,6 +112,7 @@ func init() {
 	RootCmd.AddCommand(newCmdTap())
 	RootCmd.AddCommand(newCmdTop())
 	RootCmd.AddCommand(newCmdUninject())
+	RootCmd.AddCommand(newCmdUpgrade())
 	RootCmd.AddCommand(newCmdVersion())
 }
 
@@ -300,10 +301,5 @@ func (options *proxyConfigOptions) flagSet(e pflag.ErrorHandling) *pflag.FlagSet
 	flags.MarkDeprecated("proxy-memory", "use --proxy-memory-request instead")
 	flags.MarkDeprecated("proxy-cpu", "use --proxy-cpu-request instead")
 
-	flags.BoolVar(
-		&options.ignoreCluster, "ignore-cluster", options.ignoreCluster,
-		"Ignore the current Kubernetes cluster when checking for existing cluster configuration (default false)",
-	)
-
 	return flags
 }