Make master index optional when master is used in other contexts

OpenShift provides a default URL at the root that shows the UI. The
provided flag makes loading the index handler optional for now.

pkg/master/master.go

@@ -74,8 +74,12 @@ type Config struct {
 	PortalNet         *net.IPNet
 	EnableLogsSupport bool
 	EnableUISupport   bool
+	// allow downstream consumers to disable swagger
 	EnableSwaggerSupport bool
+	// allow v1beta3 to be conditionally enabled
 	EnableV1Beta3 bool
+	// allow downstream consumers to disable the index route
+	EnableIndex            bool
 	APIPrefix              string
 	CorsAllowedOriginList  util.StringList
 	Authenticator          authenticator.Request
@@ -384,7 +388,10 @@ func (m *Master) init(c *Config) {
 
 	// Register root handler.
 	// We do not register this using restful Webservice since we do not want to surface this in api docs.
+	// Allow master to be embedded in contexts which already have something registered at the root
+	if c.EnableIndex {
 		m.mux.HandleFunc("/", apiserver.IndexHandler(m.handlerContainer, m.muxHelper))
+	}
 
 	// TODO: use go-restful
 	apiserver.InstallValidator(m.muxHelper, func() map[string]apiserver.Server { return m.getServersToValidate(c) })

pkg/master/server/server.go

@@ -247,6 +247,7 @@ func (s *APIServer) Run(_ []string) error {
 		EnableLogsSupport:      s.EnableLogsSupport,
 		EnableUISupport:        true,
 		EnableSwaggerSupport:   true,
+		EnableIndex:            true,
 		APIPrefix:              s.APIPrefix,
 		CorsAllowedOriginList:  s.CorsAllowedOriginList,
 		ReadOnlyPort:           s.ReadOnlyPort,

pkg/standalone/standalone.go

@@ -103,6 +103,7 @@ func RunApiServer(cl *client.Client, etcdClient tools.EtcdClient, addr string, p
 		},
 		EnableLogsSupport:    false,
 		EnableSwaggerSupport: true,
+		EnableIndex:          true,
 		APIPrefix:            "/api",
 		Authorizer:           apiserver.NewAlwaysAllowAuthorizer(),
 

test/integration/auth_test.go

@@ -302,6 +302,7 @@ func TestAuthModeAlwaysAllow(t *testing.T) {
 		KubeletClient:     client.FakeKubeletClient{},
 		EnableLogsSupport: false,
 		EnableUISupport:   false,
+		EnableIndex:       true,
 		APIPrefix:         "/api",
 		Authorizer:        apiserver.NewAlwaysAllowAuthorizer(),
 		AdmissionControl:  admit.NewAlwaysAdmit(),
@@ -353,6 +354,7 @@ func TestAuthModeAlwaysDeny(t *testing.T) {
 		KubeletClient:     client.FakeKubeletClient{},
 		EnableLogsSupport: false,
 		EnableUISupport:   false,
+		EnableIndex:       true,
 		APIPrefix:         "/api",
 		Authorizer:        apiserver.NewAlwaysDenyAuthorizer(),
 		AdmissionControl:  admit.NewAlwaysAdmit(),
@@ -418,6 +420,7 @@ func TestAliceNotForbiddenOrUnauthorized(t *testing.T) {
 		KubeletClient:     client.FakeKubeletClient{},
 		EnableLogsSupport: false,
 		EnableUISupport:   false,
+		EnableIndex:       true,
 		APIPrefix:         "/api",
 		Authenticator:     getTestTokenAuth(),
 		Authorizer:        allowAliceAuthorizer{},
@@ -478,6 +481,7 @@ func TestBobIsForbidden(t *testing.T) {
 		KubeletClient:     client.FakeKubeletClient{},
 		EnableLogsSupport: false,
 		EnableUISupport:   false,
+		EnableIndex:       true,
 		APIPrefix:         "/api",
 		Authenticator:     getTestTokenAuth(),
 		Authorizer:        allowAliceAuthorizer{},
@@ -538,6 +542,7 @@ func TestUnknownUserIsUnauthorized(t *testing.T) {
 		KubeletClient:     client.FakeKubeletClient{},
 		EnableLogsSupport: false,
 		EnableUISupport:   false,
+		EnableIndex:       true,
 		APIPrefix:         "/api",
 		Authenticator:     getTestTokenAuth(),
 		Authorizer:        allowAliceAuthorizer{},
@@ -617,6 +622,7 @@ func TestNamespaceAuthorization(t *testing.T) {
 		KubeletClient:     client.FakeKubeletClient{},
 		EnableLogsSupport: false,
 		EnableUISupport:   false,
+		EnableIndex:       true,
 		APIPrefix:         "/api",
 		Authenticator:     getTestTokenAuth(),
 		Authorizer:        a,
@@ -701,6 +707,7 @@ func TestKindAuthorization(t *testing.T) {
 		KubeletClient:     client.FakeKubeletClient{},
 		EnableLogsSupport: false,
 		EnableUISupport:   false,
+		EnableIndex:       true,
 		APIPrefix:         "/api",
 		Authenticator:     getTestTokenAuth(),
 		Authorizer:        a,
@@ -779,6 +786,7 @@ func TestReadOnlyAuthorization(t *testing.T) {
 		KubeletClient:     client.FakeKubeletClient{},
 		EnableLogsSupport: false,
 		EnableUISupport:   false,
+		EnableIndex:       true,
 		APIPrefix:         "/api",
 		Authenticator:     getTestTokenAuth(),
 		Authorizer:        a,