Wire in WebhookTokenAutenticator support

Signed-off-by: Simo Sorce <[email protected]>

Author: simo5

pkg/cmd/server/apis/config/helpers.go

@@ -238,6 +238,10 @@ func GetMasterFileReferences(config *MasterConfig) []*string {
 		refs = append(refs, &config.AuthConfig.RequestHeader.ClientCA)
 	}
 
+	for _, wta := range config.AuthConfig.WebhookTokenAuthenticators {
+		refs = append(refs, &wta.ConfigFile)
+	}
+
 	refs = append(refs, &config.AggregatorConfig.ProxyClientInfo.CertFile)
 	refs = append(refs, &config.AggregatorConfig.ProxyClientInfo.KeyFile)
 

pkg/cmd/server/apis/config/types.go

@@ -446,6 +446,8 @@ type MasterConfig struct {
 type MasterAuthConfig struct {
 	// RequestHeader holds options for setting up a front proxy against the the API.  It is optional.
 	RequestHeader *RequestHeaderAuthenticationOptions
+	// WebhookTokenAuthnConfig, if present configures remote token reviewers
+	WebhookTokenAuthenticators []WebhookTokenAuthenticator
 }
 
 // RequestHeaderAuthenticationOptions provides options for setting up a front proxy against the entire
@@ -828,6 +830,16 @@ type DNSConfig struct {
 	AllowRecursiveQueries bool
 }
 
+type WebhookTokenAuthenticator struct {
+	// ConfigFile is a path to a Kubeconfig file with the webhook configuration
+	ConfigFile string
+	// CacheTTL indicates how long an authentication result should be cached.
+	// It takes a valid time duration string (e.g. "5m").
+	// If empty, you get a default timeout of 10 seconds.
+	// If zero (e.g. "0m"), caching is disabled
+	CacheTTL string
+}
+
 type OAuthConfig struct {
 	// MasterCA is the CA for verifying the TLS connection back to the MasterURL.
 	// "" to use system roots, set to use custom roots, never nil (guaranteed by conversion defaults)

pkg/cmd/server/apis/config/v1/conversions.go

@@ -136,6 +136,13 @@ func SetDefaults_MasterConfig(obj *MasterConfig) {
 			obj.AdmissionConfig.PluginConfig[pluginName] = &AdmissionPluginConfig{}
 		}
 	}
+
+	// Set defaults Cache TTLs for external Webhook Token Reviewers
+	for _, wta := range obj.AuthConfig.WebhookTokenAuthenticators {
+		if len(wta.CacheTTL) == 0 {
+			wta.CacheTTL = "10s"
+		}
+	}
 }
 
 func SetDefaults_KubernetesMasterConfig(obj *KubernetesMasterConfig) {

pkg/cmd/server/apis/config/v1/testdata/master-config.yaml

@@ -28,6 +28,7 @@ auditConfig:
   webHookMode: ""
 authConfig:
   requestHeader: null
+  webhookTokenAuthenticators: null
 controllerConfig:
   controllers:
   - '*'

pkg/cmd/server/apis/config/v1/types.go

@@ -294,6 +294,8 @@ type MasterConfig struct {
 type MasterAuthConfig struct {
 	// RequestHeader holds options for setting up a front proxy against the the API.  It is optional.
 	RequestHeader *RequestHeaderAuthenticationOptions `json:"requestHeader"`
+	// WebhookTokenAuthnConfig, if present configures remote token reviewers
+	WebhookTokenAuthenticators []WebhookTokenAuthenticator `json:"webhookTokenAuthenticators"`
 }
 
 // RequestHeaderAuthenticationOptions provides options for setting up a front proxy against the entire
@@ -711,6 +713,18 @@ type DNSConfig struct {
 	AllowRecursiveQueries bool `json:"allowRecursiveQueries"`
 }
 
+// WebhookTokenAuthenticators holds the necessary configuation options for
+// external token authenticators
+type WebhookTokenAuthenticator struct {
+	// ConfigFile is a path to a Kubeconfig file with the webhook configuration
+	ConfigFile string `json:"configFile"`
+	// CacheTTL indicates how long an authentication result should be cached.
+	// It takes a valid time duration string (e.g. "5m").
+	// If empty, you get a default timeout of 10 seconds.
+	// If zero (e.g. "0m"), caching is disabled
+	CacheTTL string `json:"cacheTTL"`
+}
+
 // OAuthConfig holds the necessary configuration options for OAuth authentication
 type OAuthConfig struct {
 	// MasterCA is the CA for verifying the TLS connection back to the MasterURL.

pkg/cmd/server/apis/config/v1/zz_generated.deepcopy.go

@@ -172,6 +172,24 @@ func ValidateMasterConfig(config *configapi.MasterConfig, fldPath *field.Path) V
 func ValidateMasterAuthConfig(config configapi.MasterAuthConfig, fldPath *field.Path) ValidationResults {
 	validationResults := ValidationResults{}
 
+	for _, wta := range config.WebhookTokenAuthenticators {
+		configFile := fldPath.Child("webhookTokenAuthenticators", "ConfigFile")
+		if len(wta.ConfigFile) == 0 {
+			validationResults.AddErrors(field.Required(configFile, ""))
+		} else {
+			validationResults.AddErrors(ValidateFile(wta.ConfigFile, configFile)...)
+		}
+
+		cacheTTL := fldPath.Child("webhookTokenAuthenticators", "cacheTTL")
+		if len(wta.CacheTTL) == 0 {
+			validationResults.AddErrors(field.Required(cacheTTL, ""))
+		} else if ttl, err := time.ParseDuration(wta.CacheTTL); err != nil {
+			validationResults.AddErrors(field.Invalid(cacheTTL, wta.CacheTTL, fmt.Sprintf("%v", err)))
+		} else if ttl < 0 {
+			validationResults.AddErrors(field.Invalid(cacheTTL, wta.CacheTTL, "cannot be less than zero"))
+		}
+	}
+
 	if config.RequestHeader == nil {
 		return validationResults
 	}

pkg/cmd/server/apis/config/validation/master.go

@@ -1,6 +1,8 @@
 package validation
 
 import (
+	"io/ioutil"
+	"os"
 	"testing"
 
 	"k8s.io/apimachinery/pkg/util/diff"
@@ -525,3 +527,79 @@ func TestValidateIngressIPNetworkCIDR(t *testing.T) {
 		}
 	}
 }
+
+func TestValidateiMasterAuthConfig(t *testing.T) {
+	testConfigFile, err := ioutil.TempFile("", "test1.cfg")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	defer os.Remove(testConfigFile.Name())
+
+	testCases := []struct {
+		testName                   string
+		errorCount                 int
+		RequestHeader              *configapi.RequestHeaderAuthenticationOptions
+		WebhookTokenAuthenticators []configapi.WebhookTokenAuthenticator
+	}{
+		{
+			testName: "No AuthConfig",
+		},
+		{
+			testName: "Valid RequestHeader",
+			RequestHeader: &configapi.RequestHeaderAuthenticationOptions{
+				ClientCA:            "ClientCA",
+				ClientCommonNames:   []string{"ClientCommonNames", "2", "3"},
+				UsernameHeaders:     []string{"Username", "Headers"},
+				GroupHeaders:        []string{"Group", "Headers"},
+				ExtraHeaderPrefixes: []string{"Extra", "Header", "Prefixes"},
+			},
+		},
+		{
+			testName: "Only One WebhookTokenAuthenticator",
+			WebhookTokenAuthenticators: []configapi.WebhookTokenAuthenticator{
+				{
+					ConfigFile: testConfigFile.Name(),
+					CacheTTL:   "2m",
+				},
+			},
+		},
+		{
+			testName: "Unexisting config file in second WebhookTokenAuthenticator",
+			WebhookTokenAuthenticators: []configapi.WebhookTokenAuthenticator{
+				{
+					ConfigFile: testConfigFile.Name(),
+					CacheTTL:   "2m",
+				},
+				{
+					ConfigFile: "Unexisting",
+					CacheTTL:   "2m",
+				},
+			},
+			errorCount: 1,
+		},
+		{
+			testName: "Invalid and Empty CacheTTL WebhookTokenAuthenticator",
+			WebhookTokenAuthenticators: []configapi.WebhookTokenAuthenticator{
+				{
+					ConfigFile: testConfigFile.Name(),
+					CacheTTL:   "-2m",
+				},
+				{
+					ConfigFile: testConfigFile.Name(),
+				},
+			},
+			errorCount: 2,
+		},
+	}
+	for _, test := range testCases {
+		config := configapi.MasterAuthConfig{
+			RequestHeader:              test.RequestHeader,
+			WebhookTokenAuthenticators: test.WebhookTokenAuthenticators,
+		}
+		errors := ValidateMasterAuthConfig(config, nil)
+		errorCount := len(errors.Errors)
+		if test.errorCount != errorCount {
+			t.Errorf("%s: expected %d errors, got %v", test.testName, test.errorCount, errors.Errors)
+		}
+	}
+}

pkg/cmd/server/apis/config/validation/master_test.go

@@ -588,7 +588,7 @@ func BuildKubernetesMasterConfig(
 
 func defaultOpenAPIConfig(config configapi.MasterConfig) *openapicommon.Config {
 	securityDefinitions := spec.SecurityDefinitions{}
-	if len(config.ServiceAccountConfig.PublicKeyFiles) > 0 {
+	if len(config.ServiceAccountConfig.PublicKeyFiles) > 0 || len(config.AuthConfig.WebhookTokenAuthenticators) > 0 {
 		securityDefinitions["BearerToken"] = &spec.SecurityScheme{
 			SecuritySchemeProps: spec.SecuritySchemeProps{
 				Type:        "apiKey",

pkg/cmd/server/apis/config/zz_generated.deepcopy.go

@@ -16,6 +16,7 @@ import (
 	tokencache "k8s.io/apiserver/pkg/authentication/token/cache"
 	tokenunion "k8s.io/apiserver/pkg/authentication/token/union"
 	genericapiserver "k8s.io/apiserver/pkg/server"
+	webhooktoken "k8s.io/apiserver/plugin/pkg/authenticator/token/webhook"
 	kclientsetexternal "k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/rest"
 	"k8s.io/client-go/util/cert"
@@ -108,6 +109,18 @@ func newAuthenticator(config configapi.MasterConfig, accessTokenGetter oauthclie
 			group.NewTokenGroupAdder(oauthTokenAuthenticator, []string{bootstrappolicy.AuthenticatedOAuthGroup}))
 	}
 
+	for _, wta := range config.AuthConfig.WebhookTokenAuthenticators {
+		ttl, err := time.ParseDuration(wta.CacheTTL)
+		if err != nil {
+			return nil, nil, fmt.Errorf("Error converting CacheTTL='%s' to duration", wta.CacheTTL)
+		}
+		webhookTokenAuthenticator, err := webhooktoken.New(wta.ConfigFile, ttl)
+		if err != nil {
+			return nil, nil, fmt.Errorf("Failed to create webhook token authenticator for ConfigFile='%s'", wta.ConfigFile)
+		}
+		tokenAuthenticators = append(tokenAuthenticators, webhookTokenAuthenticator)
+	}
+
 	if len(tokenAuthenticators) > 0 {
 		// Combine all token authenticators
 		tokenAuth := tokenunion.New(tokenAuthenticators...)