feat: add controller-isleader xweb component to return 200 if the con…

…troller is a raft leader

controller/controller.go

@@ -313,6 +313,10 @@ func (c *Controller) initWeb() {
 		logrus.WithError(err).Fatalf("failed to create single page application factory")
 	}
 
+	if err = c.xweb.GetRegistry().Add(webapis.NewControllerIsLeaderApiFactory(c.env)); err != nil {
+		logrus.WithError(err).Fatalf("failed to create controller-is-leader api factory")
+	}
+
 	if c.IsEdgeEnabled() {
 		managementApiFactory := webapis.NewManagementApiFactory(c.env)
 		clientApiFactory := webapis.NewClientApiFactory(c.env)
@@ -663,6 +667,8 @@ func getApiPath(binding string) string {
 		return "health-checks"
 	case "edge-oidc":
 		return "/oidc"
+	case "controller-isleader":
+		return "/sys/health"
 	}
 
 	return ""

controller/webapis/controller-isleader.go

@@ -0,0 +1,102 @@
+/*
+	Copyright NetFoundry Inc.
+
+	Licensed under the Apache License, Version 2.0 (the "License");
+	you may not use this file except in compliance with the License.
+	You may obtain a copy of the License at
+
+	https://www.apache.org/licenses/LICENSE-2.0
+
+	Unless required by applicable law or agreed to in writing, software
+	distributed under the License is distributed on an "AS IS" BASIS,
+	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+	See the License for the specific language governing permissions and
+	limitations under the License.
+*/
+
+package webapis
+
+import (
+	"encoding/json"
+	"github.com/openziti/xweb/v2"
+	"github.com/openziti/ziti/controller/env"
+	"github.com/sirupsen/logrus"
+	"net/http"
+	"strings"
+)
+
+var _ xweb.ApiHandlerFactory = &ControllerIsLeaderApiFactory{}
+
+type ControllerIsLeaderApiFactory struct {
+	appEnv *env.AppEnv
+}
+
+func (factory ControllerIsLeaderApiFactory) Validate(config *xweb.InstanceConfig) error {
+	return nil
+}
+
+func NewControllerIsLeaderApiFactory(appEnv *env.AppEnv) *ControllerIsLeaderApiFactory {
+	return &ControllerIsLeaderApiFactory{
+		appEnv: appEnv,
+	}
+}
+
+func (factory ControllerIsLeaderApiFactory) Binding() string {
+	return ControllerIsLeaderApiBinding
+}
+
+func (factory ControllerIsLeaderApiFactory) New(_ *xweb.ServerConfig, options map[interface{}]interface{}) (xweb.ApiHandler, error) {
+	return &ControllerIsLeaderApiHandler{
+		appEnv:  factory.appEnv,
+		options: options,
+	}, nil
+
+}
+
+type ControllerIsLeaderApiHandler struct {
+	handler http.Handler
+	options map[interface{}]interface{}
+	appEnv  *env.AppEnv
+}
+
+func (self ControllerIsLeaderApiHandler) Binding() string {
+	return ControllerIsLeaderApiBinding
+}
+
+func (self ControllerIsLeaderApiHandler) Options() map[interface{}]interface{} {
+	return self.options
+}
+
+func (self ControllerIsLeaderApiHandler) RootPath() string {
+	return "/sys/health"
+}
+
+func (self ControllerIsLeaderApiHandler) IsHandler(r *http.Request) bool {
+	return strings.HasPrefix(r.URL.Path, self.RootPath())
+}
+
+func (self *ControllerIsLeaderApiHandler) ServeHTTP(w http.ResponseWriter, request *http.Request) {
+	output := map[string]interface{}{}
+	output["meta"] = map[string]interface{}{}
+
+	data := map[string]interface{}{}
+	output["data"] = data
+
+	w.Header().Set("Content-Type", "application/json")
+	encoder := json.NewEncoder(w)
+	encoder.SetIndent("", "    ")
+
+	isLeader := self.appEnv.GetHostController().IsRaftLeader()
+	data["isLeader"] = isLeader
+	if !isLeader {
+		w.WriteHeader(429)
+	}
+
+	if err := encoder.Encode(output); err != nil {
+		logrus.WithError(err).Error("failure encoding health check results")
+	}
+}
+
+func (self ControllerIsLeaderApiHandler) IsDefault() bool {
+	return false
+}

controller/webapis/versions.go

@@ -24,21 +24,24 @@ const (
 	RestApiRootPath       = "/edge"
 	ClientRestApiBase     = "/edge/client"
 	ManagementRestApiBase = "/edge/management"
+	ControllerIsLeader    = "/sys/health"
 
-	LegacyClientRestApiBaseUrlV1 = RestApiRootPath + RestApiV1
-	ClientRestApiBaseUrlV1       = ClientRestApiBase + RestApiV1
-	ManagementRestApiBaseUrlV1   = ManagementRestApiBase + RestApiV1
+	LegacyClientRestApiBaseUrlV1   = RestApiRootPath + RestApiV1
+	ClientRestApiBaseUrlV1         = ClientRestApiBase + RestApiV1
+	ManagementRestApiBaseUrlV1     = ManagementRestApiBase + RestApiV1
+	ControllerIsLeaderApiBaseUrlV1 = ControllerIsLeader + RestApiV1
 
 	ClientRestApiBaseUrlLatest     = ClientRestApiBaseUrlV1
 	ManagementRestApiBaseUrlLatest = ManagementRestApiBaseUrlV1
 
 	ClientRestApiSpecUrl     = ClientRestApiBaseUrlLatest + "/swagger.json"
 	ManagementRestApiSpecUrl = ManagementRestApiBaseUrlLatest + "/swagger.json"
 
-	LegacyClientApiBinding = "edge"
-	ClientApiBinding       = "edge-client"
-	ManagementApiBinding   = "edge-management"
-	OidcApiBinding         = "edge-oidc"
+	LegacyClientApiBinding       = "edge"
+	ClientApiBinding             = "edge-client"
+	ManagementApiBinding         = "edge-management"
+	OidcApiBinding               = "edge-oidc"
+	ControllerIsLeaderApiBinding = "controller-isleader"
 )
 
 // AllApiBindingVersions is a map of: API Binding -> Api Version -> API Path
@@ -50,4 +53,7 @@ var AllApiBindingVersions = map[string]map[string]string{
 	ManagementApiBinding: {
 		VersionV1: ManagementRestApiBaseUrlV1,
 	},
+	ControllerIsLeaderApiBinding: {
+		VersionV1: ControllerIsLeaderApiBaseUrlV1,
+	},
 }