api/etcdhttp: change /health type back to string for backwards compatibility

Documentation/upgrades/upgrade_3_3.md

@@ -74,23 +74,23 @@ Set `embed.Config.Debug` field to `true` to enable gRPC server logs.
 
 #### Change in `/health` endpoint response value
 
-Previously, `[endpoint]:[client-port]/health` returned manually marshaled JSON value. 3.3 instead defines [`etcdhttp.Health`](https://godoc.org/github.com/coreos/etcd/etcdserver/api/etcdhttp#Health) struct and returns properly encoded JSON value with errors, if any.
+Previously, `[endpoint]:[client-port]/health` returned manually marshaled JSON value. 3.3 now defines [`etcdhttp.Health`](https://godoc.org/github.com/coreos/etcd/etcdserver/api/etcdhttp#Health) struct and includes errors, if any.
 
 Before
 
 ```bash
 $ curl http://localhost:2379/health
-{"health": "true"}
+{"health":"true"}
 ```
 
 After
 
 ```bash
 $ curl http://localhost:2379/health
-{"health":true}
+{"health":"true"}
 
 # Or
-{"health":false,"errors":["NOSPACE"]}
+{"health":"false","errors":["NOSPACE"]}
 ```
 
 #### Change in gRPC gateway HTTP endpoints (replaced `/v3alpha` with `/v3beta`)

Documentation/v2/admin_guide.md

@@ -45,12 +45,12 @@ It is important to monitor your production etcd cluster for healthy information
 
 #### Health Monitoring
 
-At lowest level, etcd exposes health information via HTTP at `/health` in JSON format. If it returns `{"health":true}`, then the cluster is healthy.
+At lowest level, etcd exposes health information via HTTP at `/health` in JSON format. If it returns `{"health":"true"}`, then the cluster is healthy.
 
 ```
 $ curl -L http://127.0.0.1:2379/health
 
-{"health":true}
+{"health":"true"}
 ```
 
 You can also use etcdctl to check the cluster-wide health information. It will contact all the members of the cluster and collect the health information for you.

Documentation/v2/other_apis.md

@@ -29,5 +29,5 @@ curl http://10.0.0.10:2379/health
 ```
 
 ```json
-{"health":true}
+{"health":"true"}
 ```

e2e/ctl_v3_alarm_test.go

@@ -53,7 +53,7 @@ func alarmTest(cx ctlCtx) {
 	}
 
 	// '/health' handler should return 'false'
-	if err := cURLGet(cx.epc, cURLReq{endpoint: "/health", expected: `{"health":false,"errors":["NOSPACE"]}`}); err != nil {
+	if err := cURLGet(cx.epc, cURLReq{endpoint: "/health", expected: `{"health":"false","errors":["NOSPACE"]}`}); err != nil {
 		cx.t.Fatalf("failed get with curl (%v)", err)
 	}
 

e2e/metrics_test.go

@@ -45,7 +45,7 @@ func metricsTest(cx ctlCtx) {
 	if err := cURLGet(cx.epc, cURLReq{endpoint: "/metrics", expected: fmt.Sprintf(`etcd_server_version{server_version="%s"} 1`, version.Version), metricsURLScheme: cx.cfg.metricsURLScheme}); err != nil {
 		cx.t.Fatalf("failed get with curl (%v)", err)
 	}
-	if err := cURLGet(cx.epc, cURLReq{endpoint: "/health", expected: `{"health":true}`, metricsURLScheme: cx.cfg.metricsURLScheme}); err != nil {
+	if err := cURLGet(cx.epc, cURLReq{endpoint: "/health", expected: `{"health":"true"}`, metricsURLScheme: cx.cfg.metricsURLScheme}); err != nil {
 		cx.t.Fatalf("failed get with curl (%v)", err)
 	}
 }

etcdserver/api/etcdhttp/metrics.go

@@ -58,7 +58,7 @@ func NewHealthHandler(hfunc func() Health) http.HandlerFunc {
 		}
 		h := hfunc()
 		d, _ := json.Marshal(h)
-		if !h.Health {
+		if h.Health != "true" {
 			http.Error(w, string(d), http.StatusServiceUnavailable)
 			return
 		}
@@ -70,12 +70,12 @@ func NewHealthHandler(hfunc func() Health) http.HandlerFunc {
 // Health defines etcd server health status.
 // TODO: remove manual parsing in etcdctl cluster-health
 type Health struct {
-	Health bool     `json:"health"`
+	Health string   `json:"health"`
 	Errors []string `json:"errors,omitempty"`
 }
 
 func checkHealth(srv etcdserver.ServerV2) Health {
-	h := Health{Health: false}
+	h := Health{Health: "false"}
 
 	as := srv.Alarms()
 	if len(as) > 0 {
@@ -96,7 +96,8 @@ func checkHealth(srv etcdserver.ServerV2) Health {
 	if err != nil {
 		h.Errors = append(h.Errors, err.Error())
 	}
-
-	h.Health = err == nil
+	if err == nil {
+		h.Health = "true"
+	}
 	return h
 }

proxy/grpcproxy/health.go

@@ -30,12 +30,14 @@ func HandleHealth(mux *http.ServeMux, c *clientv3.Client) {
 }
 
 func checkHealth(c *clientv3.Client) etcdhttp.Health {
-	h := etcdhttp.Health{Health: false}
+	h := etcdhttp.Health{Health: "false"}
 	ctx, cancel := context.WithTimeout(c.Ctx(), time.Second)
 	_, err := c.Get(ctx, "a")
 	cancel()
-	h.Health = err == nil || err == rpctypes.ErrPermissionDenied
-	if !h.Health {
+	if err == nil || err == rpctypes.ErrPermissionDenied {
+		h.Health = "true"
+	}
+	if h.Health != "true" {
 		h.Errors = append(h.Errors, err.Error())
 	}
 	return h