*: remove "errors" field in /health endpoint

Documentation/upgrades/upgrade_3_3.md

@@ -72,27 +72,17 @@ cfg.SetupLogging()
 
 Set `embed.Config.Debug` field to `true` to enable gRPC server logs.
 
-#### Change in `/health` endpoint response value
+#### Change in `/health` endpoint response
 
-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. Note that `"health"` field in `etcdhttp.Health` is `string` type (was boolean in v3.3.0-rc.0,1,2 but reverted to `string` for backward compatibilities).
+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.
 
-Before
+Note that in v3.3.0-rc.0, v3.3.0-rc.1, and v3.3.0-rc.2, `etcdhttp.Health` has boolean type `"health"` and `"errors"` fields. For backward compatibilities, we reverted `"health"` field to `string` type and removed `"errors"` field. Further health information will be provided in separate APIs.
 
 ```bash
 $ curl http://localhost:2379/health
 {"health":"true"}
 ```
 
-After
-
-```bash
-$ curl http://localhost:2379/health
-{"health":"true"}
-
-# Or
-{"health":"false","errors":["NOSPACE"]}
-```
-
 #### Change in gRPC gateway HTTP endpoints (replaced `/v3alpha` with `/v3beta`)
 
 Before

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"}`}); err != nil {
 		cx.t.Fatalf("failed get with curl (%v)", err)
 	}
 

etcdserver/api/etcdhttp/metrics.go

@@ -70,34 +70,32 @@ 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 string   `json:"health"`
-	Errors []string `json:"errors,omitempty"`
+	Health string `json:"health"`
 }
 
+// TODO: server NOSPACE, etcdserver.ErrNoLeader in health API
+
 func checkHealth(srv etcdserver.ServerV2) Health {
-	h := Health{Health: "false"}
+	h := Health{Health: "true"}
 
 	as := srv.Alarms()
 	if len(as) > 0 {
-		for _, v := range as {
-			h.Errors = append(h.Errors, v.Alarm.String())
-		}
-		return h
+		h.Health = "false"
 	}
 
-	if uint64(srv.Leader()) == raft.None {
-		h.Errors = append(h.Errors, etcdserver.ErrNoLeader.Error())
-		return h
+	if h.Health == "true" {
+		if uint64(srv.Leader()) == raft.None {
+			h.Health = "false"
+		}
 	}
 
-	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
-	_, err := srv.Do(ctx, etcdserverpb.Request{Method: "QGET"})
-	cancel()
-	if err != nil {
-		h.Errors = append(h.Errors, err.Error())
-	}
-	if err == nil {
-		h.Health = "true"
+	if h.Health == "true" {
+		ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+		_, err := srv.Do(ctx, etcdserverpb.Request{Method: "QGET"})
+		cancel()
+		if err != nil {
+			h.Health = "false"
+		}
 	}
 	return h
 }

proxy/grpcproxy/health.go

@@ -37,8 +37,5 @@ func checkHealth(c *clientv3.Client) etcdhttp.Health {
 	if err == nil || err == rpctypes.ErrPermissionDenied {
 		h.Health = "true"
 	}
-	if h.Health != "true" {
-		h.Errors = append(h.Errors, err.Error())
-	}
 	return h
 }