feat(*): add flags/env for kube api tls overrides

Add a new flags and associated environment variables to override
 the TLS Settings used when constructing the Kube Client.

- `--kube-insecure-skip-tls-verify | HELM_KUBEINSECURE_SKIP_TLS_VERIFY`: if true, the kube api server's certificate will not be checked for validity. This will make your HTTPS connections insecure
- `--kube-tls-server-name | HELM_KUBETLS_SERVER_NAME`: server name to use for kube api server certificate validation. If it is not provided, the hostname used to contact the server is used

Signed-off-by: Justen Walker <justen.walker+github@gmail.com>

cmd/helm/load_plugins.go

@@ -154,7 +154,7 @@ func callPluginExecutable(pluginName string, main string, argv []string, out io.
 func manuallyProcessArgs(args []string) ([]string, []string) {
 	known := []string{}
 	unknown := []string{}
-	kvargs := []string{"--kube-context", "--namespace", "-n", "--kubeconfig", "--kube-apiserver", "--kube-token", "--kube-as-user", "--kube-as-group", "--kube-ca-file", "--registry-config", "--repository-cache", "--repository-config"}
+	kvargs := []string{"--kube-context", "--namespace", "-n", "--kubeconfig", "--kube-apiserver", "--kube-token", "--kube-as-user", "--kube-as-group", "--kube-ca-file", "--registry-config", "--repository-cache", "--repository-config", "--insecure-skip-tls-verify", "--tls-server-name"}
 	knownArg := func(a string) bool {
 		for _, pre := range kvargs {
 			if strings.HasPrefix(a, pre+"=") {

cmd/helm/root.go

@@ -67,6 +67,8 @@ Environment variables:
 | $HELM_KUBEASUSER                   | set the Username to impersonate for the operation.                                                |
 | $HELM_KUBECONTEXT                  | set the name of the kubeconfig context.                                                           |
 | $HELM_KUBETOKEN                    | set the Bearer KubeToken used for authentication.                                                 |
+| $HELM_KUBEINSECURE_SKIP_TLS_VERIFY | indicate if the Kubernetes API server's certificate validation should be skipped (insecure)       |
+| $HELM_KUBETLS_SERVER_NAME          | set the server name used to validate the Kubernetes API server certificate                        |
 | $HELM_BURST_LIMIT                  | set the default burst limit in the case the server contains many CRDs (default 100, -1 to disable)|
 
 Helm stores cache, configuration, and data based on the following configuration order:

cmd/helm/testdata/output/env-comp.txt

@@ -9,6 +9,8 @@ HELM_KUBEASGROUPS
 HELM_KUBEASUSER
 HELM_KUBECAFILE
 HELM_KUBECONTEXT
+HELM_KUBEINSECURE_SKIP_TLS_VERIFY
+HELM_KUBETLS_SERVER_NAME
 HELM_KUBETOKEN
 HELM_MAX_HISTORY
 HELM_NAMESPACE

pkg/cli/environment.go

@@ -60,6 +60,12 @@ type EnvSettings struct {
 	KubeAPIServer string
 	// Custom certificate authority file.
 	KubeCaFile string
+	// KubeInsecureSkipTLSVerify indicates if server's certificate will not be checked for validity.
+	// This makes the HTTPS connections insecure
+	KubeInsecureSkipTLSVerify bool
+	// KubeTLSServerName overrides the name to use for server certificate validation.
+	// If it is not provided, the hostname used to contact the server is used
+	KubeTLSServerName string
 	// Debug indicates whether or not Helm is running in Debug mode.
 	Debug bool
 	// RegistryConfig is the path to the registry config file.
@@ -78,19 +84,21 @@ type EnvSettings struct {
 
 func New() *EnvSettings {
 	env := &EnvSettings{
-		namespace:        os.Getenv("HELM_NAMESPACE"),
-		MaxHistory:       envIntOr("HELM_MAX_HISTORY", defaultMaxHistory),
-		KubeContext:      os.Getenv("HELM_KUBECONTEXT"),
-		KubeToken:        os.Getenv("HELM_KUBETOKEN"),
-		KubeAsUser:       os.Getenv("HELM_KUBEASUSER"),
-		KubeAsGroups:     envCSV("HELM_KUBEASGROUPS"),
-		KubeAPIServer:    os.Getenv("HELM_KUBEAPISERVER"),
-		KubeCaFile:       os.Getenv("HELM_KUBECAFILE"),
-		PluginsDirectory: envOr("HELM_PLUGINS", helmpath.DataPath("plugins")),
-		RegistryConfig:   envOr("HELM_REGISTRY_CONFIG", helmpath.ConfigPath("registry/config.json")),
-		RepositoryConfig: envOr("HELM_REPOSITORY_CONFIG", helmpath.ConfigPath("repositories.yaml")),
-		RepositoryCache:  envOr("HELM_REPOSITORY_CACHE", helmpath.CachePath("repository")),
-		BurstLimit:       envIntOr("HELM_BURST_LIMIT", defaultBurstLimit),
+		namespace:                 os.Getenv("HELM_NAMESPACE"),
+		MaxHistory:                envIntOr("HELM_MAX_HISTORY", defaultMaxHistory),
+		KubeContext:               os.Getenv("HELM_KUBECONTEXT"),
+		KubeToken:                 os.Getenv("HELM_KUBETOKEN"),
+		KubeAsUser:                os.Getenv("HELM_KUBEASUSER"),
+		KubeAsGroups:              envCSV("HELM_KUBEASGROUPS"),
+		KubeAPIServer:             os.Getenv("HELM_KUBEAPISERVER"),
+		KubeCaFile:                os.Getenv("HELM_KUBECAFILE"),
+		KubeTLSServerName:         os.Getenv("HELM_KUBETLS_SERVER_NAME"),
+		KubeInsecureSkipTLSVerify: envBoolOr("HELM_KUBEINSECURE_SKIP_TLS_VERIFY", false),
+		PluginsDirectory:          envOr("HELM_PLUGINS", helmpath.DataPath("plugins")),
+		RegistryConfig:            envOr("HELM_REGISTRY_CONFIG", helmpath.ConfigPath("registry/config.json")),
+		RepositoryConfig:          envOr("HELM_REPOSITORY_CONFIG", helmpath.ConfigPath("repositories.yaml")),
+		RepositoryCache:           envOr("HELM_REPOSITORY_CACHE", helmpath.CachePath("repository")),
+		BurstLimit:                envIntOr("HELM_BURST_LIMIT", defaultBurstLimit),
 	}
 	env.Debug, _ = strconv.ParseBool(os.Getenv("HELM_DEBUG"))
 
@@ -103,6 +111,8 @@ func New() *EnvSettings {
 		CAFile:           &env.KubeCaFile,
 		KubeConfig:       &env.KubeConfig,
 		Impersonate:      &env.KubeAsUser,
+		Insecure:         &env.KubeInsecureSkipTLSVerify,
+		TLSServerName:    &env.KubeTLSServerName,
 		ImpersonateGroup: &env.KubeAsGroups,
 		WrapConfigFn: func(config *rest.Config) *rest.Config {
 			config.Burst = env.BurstLimit
@@ -122,6 +132,8 @@ func (s *EnvSettings) AddFlags(fs *pflag.FlagSet) {
 	fs.StringArrayVar(&s.KubeAsGroups, "kube-as-group", s.KubeAsGroups, "group to impersonate for the operation, this flag can be repeated to specify multiple groups.")
 	fs.StringVar(&s.KubeAPIServer, "kube-apiserver", s.KubeAPIServer, "the address and the port for the Kubernetes API server")
 	fs.StringVar(&s.KubeCaFile, "kube-ca-file", s.KubeCaFile, "the certificate authority file for the Kubernetes API server connection")
+	fs.StringVar(&s.KubeTLSServerName, "kube-tls-server-name", s.KubeTLSServerName, "server name to use for Kubernetes API server certificate validation. If it is not provided, the hostname used to contact the server is used")
+	fs.BoolVar(&s.KubeInsecureSkipTLSVerify, "kube-insecure-skip-tls-verify", s.KubeInsecureSkipTLSVerify, "if true, the Kubernetes API server's certificate will not be checked for validity. This will make your HTTPS connections insecure")
 	fs.BoolVar(&s.Debug, "debug", s.Debug, "enable verbose output")
 	fs.StringVar(&s.RegistryConfig, "registry-config", s.RegistryConfig, "path to the registry config file")
 	fs.StringVar(&s.RepositoryConfig, "repository-config", s.RepositoryConfig, "path to the file containing repository names and URLs")
@@ -136,6 +148,18 @@ func envOr(name, def string) string {
 	return def
 }
 
+func envBoolOr(name string, def bool) bool {
+	if name == "" {
+		return def
+	}
+	envVal := envOr(name, strconv.FormatBool(def))
+	ret, err := strconv.ParseBool(envVal)
+	if err != nil {
+		return def
+	}
+	return ret
+}
+
 func envIntOr(name string, def int) int {
 	if name == "" {
 		return def
@@ -172,12 +196,14 @@ func (s *EnvSettings) EnvVars() map[string]string {
 		"HELM_BURST_LIMIT":       strconv.Itoa(s.BurstLimit),
 
 		// broken, these are populated from helm flags and not kubeconfig.
-		"HELM_KUBECONTEXT":   s.KubeContext,
-		"HELM_KUBETOKEN":     s.KubeToken,
-		"HELM_KUBEASUSER":    s.KubeAsUser,
-		"HELM_KUBEASGROUPS":  strings.Join(s.KubeAsGroups, ","),
-		"HELM_KUBEAPISERVER": s.KubeAPIServer,
-		"HELM_KUBECAFILE":    s.KubeCaFile,
+		"HELM_KUBECONTEXT":                  s.KubeContext,
+		"HELM_KUBETOKEN":                    s.KubeToken,
+		"HELM_KUBEASUSER":                   s.KubeAsUser,
+		"HELM_KUBEASGROUPS":                 strings.Join(s.KubeAsGroups, ","),
+		"HELM_KUBEAPISERVER":                s.KubeAPIServer,
+		"HELM_KUBECAFILE":                   s.KubeCaFile,
+		"HELM_KUBEINSECURE_SKIP_TLS_VERIFY": strconv.FormatBool(s.KubeInsecureSkipTLSVerify),
+		"HELM_KUBETLS_SERVER_NAME":          s.KubeTLSServerName,
 	}
 	if s.KubeConfig != "" {
 		envvars["KUBECONFIG"] = s.KubeConfig

pkg/cli/environment_test.go

@@ -48,13 +48,15 @@ func TestEnvSettings(t *testing.T) {
 		envvars map[string]string
 
 		// expected values
-		ns, kcontext string
-		debug        bool
-		maxhistory   int
-		kubeAsUser   string
-		kubeAsGroups []string
-		kubeCaFile   string
-		burstLimit   int
+		ns, kcontext  string
+		debug         bool
+		maxhistory    int
+		kubeAsUser    string
+		kubeAsGroups  []string
+		kubeCaFile    string
+		kubeInsecure  bool
+		kubeTLSServer string
+		burstLimit    int
 	}{
 		{
 			name:       "defaults",
@@ -63,38 +65,44 @@ func TestEnvSettings(t *testing.T) {
 			burstLimit: defaultBurstLimit,
 		},
 		{
-			name:         "with flags set",
-			args:         "--debug --namespace=myns --kube-as-user=poro --kube-as-group=admins --kube-as-group=teatime --kube-as-group=snackeaters --kube-ca-file=/tmp/ca.crt --burst-limit 100",
-			ns:           "myns",
-			debug:        true,
-			maxhistory:   defaultMaxHistory,
-			burstLimit:   100,
-			kubeAsUser:   "poro",
-			kubeAsGroups: []string{"admins", "teatime", "snackeaters"},
-			kubeCaFile:   "/tmp/ca.crt",
+			name:          "with flags set",
+			args:          "--debug --namespace=myns --kube-as-user=poro --kube-as-group=admins --kube-as-group=teatime --kube-as-group=snackeaters --kube-ca-file=/tmp/ca.crt --burst-limit 100 --kube-insecure-skip-tls-verify=true --kube-tls-server-name=example.org",
+			ns:            "myns",
+			debug:         true,
+			maxhistory:    defaultMaxHistory,
+			burstLimit:    100,
+			kubeAsUser:    "poro",
+			kubeAsGroups:  []string{"admins", "teatime", "snackeaters"},
+			kubeCaFile:    "/tmp/ca.crt",
+			kubeTLSServer: "example.org",
+			kubeInsecure:  true,
 		},
 		{
-			name:         "with envvars set",
-			envvars:      map[string]string{"HELM_DEBUG": "1", "HELM_NAMESPACE": "yourns", "HELM_KUBEASUSER": "pikachu", "HELM_KUBEASGROUPS": ",,,operators,snackeaters,partyanimals", "HELM_MAX_HISTORY": "5", "HELM_KUBECAFILE": "/tmp/ca.crt", "HELM_BURST_LIMIT": "150"},
-			ns:           "yourns",
-			maxhistory:   5,
-			burstLimit:   150,
-			debug:        true,
-			kubeAsUser:   "pikachu",
-			kubeAsGroups: []string{"operators", "snackeaters", "partyanimals"},
-			kubeCaFile:   "/tmp/ca.crt",
+			name:          "with envvars set",
+			envvars:       map[string]string{"HELM_DEBUG": "1", "HELM_NAMESPACE": "yourns", "HELM_KUBEASUSER": "pikachu", "HELM_KUBEASGROUPS": ",,,operators,snackeaters,partyanimals", "HELM_MAX_HISTORY": "5", "HELM_KUBECAFILE": "/tmp/ca.crt", "HELM_BURST_LIMIT": "150", "HELM_KUBEINSECURE_SKIP_TLS_VERIFY": "true", "HELM_KUBETLS_SERVER_NAME": "example.org"},
+			ns:            "yourns",
+			maxhistory:    5,
+			burstLimit:    150,
+			debug:         true,
+			kubeAsUser:    "pikachu",
+			kubeAsGroups:  []string{"operators", "snackeaters", "partyanimals"},
+			kubeCaFile:    "/tmp/ca.crt",
+			kubeTLSServer: "example.org",
+			kubeInsecure:  true,
 		},
 		{
-			name:         "with flags and envvars set",
-			args:         "--debug --namespace=myns --kube-as-user=poro --kube-as-group=admins --kube-as-group=teatime --kube-as-group=snackeaters --kube-ca-file=/my/ca.crt --burst-limit 175",
-			envvars:      map[string]string{"HELM_DEBUG": "1", "HELM_NAMESPACE": "yourns", "HELM_KUBEASUSER": "pikachu", "HELM_KUBEASGROUPS": ",,,operators,snackeaters,partyanimals", "HELM_MAX_HISTORY": "5", "HELM_KUBECAFILE": "/tmp/ca.crt", "HELM_BURST_LIMIT": "200"},
-			ns:           "myns",
-			debug:        true,
-			maxhistory:   5,
-			burstLimit:   175,
-			kubeAsUser:   "poro",
-			kubeAsGroups: []string{"admins", "teatime", "snackeaters"},
-			kubeCaFile:   "/my/ca.crt",
+			name:          "with flags and envvars set",
+			args:          "--debug --namespace=myns --kube-as-user=poro --kube-as-group=admins --kube-as-group=teatime --kube-as-group=snackeaters --kube-ca-file=/my/ca.crt --burst-limit 175 --kube-insecure-skip-tls-verify=true --kube-tls-server-name=example.org",
+			envvars:       map[string]string{"HELM_DEBUG": "1", "HELM_NAMESPACE": "yourns", "HELM_KUBEASUSER": "pikachu", "HELM_KUBEASGROUPS": ",,,operators,snackeaters,partyanimals", "HELM_MAX_HISTORY": "5", "HELM_KUBECAFILE": "/tmp/ca.crt", "HELM_BURST_LIMIT": "200", "HELM_KUBEINSECURE_SKIP_TLS_VERIFY": "true", "HELM_KUBETLS_SERVER_NAME": "example.org"},
+			ns:            "myns",
+			debug:         true,
+			maxhistory:    5,
+			burstLimit:    175,
+			kubeAsUser:    "poro",
+			kubeAsGroups:  []string{"admins", "teatime", "snackeaters"},
+			kubeCaFile:    "/my/ca.crt",
+			kubeTLSServer: "example.org",
+			kubeInsecure:  true,
 		},
 	}
 
@@ -136,6 +144,89 @@ func TestEnvSettings(t *testing.T) {
 			if tt.burstLimit != settings.BurstLimit {
 				t.Errorf("expected BurstLimit %d, got %d", tt.burstLimit, settings.BurstLimit)
 			}
+			if tt.kubeInsecure != settings.KubeInsecureSkipTLSVerify {
+				t.Errorf("expected kubeInsecure %t, got %t", tt.kubeInsecure, settings.KubeInsecureSkipTLSVerify)
+			}
+			if tt.kubeTLSServer != settings.KubeTLSServerName {
+				t.Errorf("expected kubeTLSServer %q, got %q", tt.kubeTLSServer, settings.KubeTLSServerName)
+			}
+		})
+	}
+}
+
+func TestEnvOrBool(t *testing.T) {
+	const envName = "TEST_ENV_OR_BOOL"
+	tests := []struct {
+		name     string
+		env      string
+		val      string
+		def      bool
+		expected bool
+	}{
+		{
+			name:     "unset with default false",
+			def:      false,
+			expected: false,
+		},
+		{
+			name:     "unset with default true",
+			def:      true,
+			expected: true,
+		},
+		{
+			name:     "blank env with default false",
+			env:      envName,
+			def:      false,
+			expected: false,
+		},
+		{
+			name:     "blank env with default true",
+			env:      envName,
+			def:      true,
+			expected: true,
+		},
+		{
+			name:     "env true with default false",
+			env:      envName,
+			val:      "true",
+			def:      false,
+			expected: true,
+		},
+		{
+			name:     "env false with default true",
+			env:      envName,
+			val:      "false",
+			def:      true,
+			expected: false,
+		},
+		{
+			name:     "env fails parsing with default true",
+			env:      envName,
+			val:      "NOT_A_BOOL",
+			def:      true,
+			expected: true,
+		},
+		{
+			name:     "env fails parsing with default false",
+			env:      envName,
+			val:      "NOT_A_BOOL",
+			def:      false,
+			expected: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.env != "" {
+				t.Cleanup(func() {
+					os.Unsetenv(tt.env)
+				})
+				os.Setenv(tt.env, tt.val)
+			}
+			actual := envBoolOr(tt.env, tt.def)
+			if actual != tt.expected {
+				t.Errorf("expected result %t, got %t", tt.expected, actual)
+			}
 		})
 	}
 }