Add read-write, read-only and primary routes

VERSION

@@ -1 +1 @@
-1.1.0
+1.2.0

src/backend.go

@@ -10,7 +10,9 @@ import (
 // and forward requests from frontend
 type Backend interface {
 	IsPrimary() (bool, error)
+	IsReadWrite() (bool, error)
 	IsReplica() (bool, error)
+	IsReadOnly() (bool, error)
 }
 
 // NewBackend creates a backend from a driver, a connection string
@@ -90,12 +92,22 @@ func (b HTTPBackend) request(key string) (bool, error) {
 	return state.(bool), nil
 }
 
-// IsPrimary will call /master route on patroni API
+// IsPrimary will call /primary route on patroni API
 func (b HTTPBackend) IsPrimary() (bool, error) {
-	return b.request("master")
+	return b.request("primary")
+}
+
+// IsReadWrite will call /read-write route on patroni API
+func (b HTTPBackend) IsReadWrite() (bool, error) {
+	return b.request("read-write")
 }
 
 // IsReplica will call /replica route on patroni API
 func (b HTTPBackend) IsReplica() (bool, error) {
 	return b.request("replica")
 }
+
+// IsReadOnly will call /read-only route on patroni API
+func (b HTTPBackend) IsReadOnly() (bool, error) {
+	return b.request("read-only")
+}

src/frontend.go

@@ -34,7 +34,10 @@ func (f *Frontend) Start() error {
 	Debug("registering routes")
 	r.HandleFunc("/health", HealthHandler).Methods("GET")
 	r.HandleFunc("/master", PrimaryHandler).Methods("GET", "OPTIONS")
+	r.HandleFunc("/primary", PrimaryHandler).Methods("GET", "OPTIONS")
+	r.HandleFunc("/read-write", ReadWriteHandler).Methods("GET", "OPTIONS")
 	r.HandleFunc("/replica", ReplicaHandler).Methods("GET", "OPTIONS")
+	r.HandleFunc("/read-only", ReadOnlyHandler).Methods("GET", "OPTIONS")
 
 	Info("listening on %s", f)
 	var err error
@@ -148,6 +151,24 @@ func PrimaryHandler(w http.ResponseWriter, r *http.Request) {
 	io.WriteString(w, message)
 }
 
+// ReadWriteHandler exposes read-write status
+func ReadWriteHandler(w http.ResponseWriter, r *http.Request) {
+	var message string
+	var status int
+	readWrite, err := backend.IsReadWrite()
+	if err != nil {
+		message = fmt.Sprintf("{\"error\":\"%v\"}", err)
+		status = http.StatusServiceUnavailable
+	}
+	message = fmt.Sprintf("{\"read-write\":%t}", readWrite)
+	status = http.StatusServiceUnavailable
+	if readWrite {
+		status = http.StatusOK
+	}
+	w.WriteHeader(status)
+	io.WriteString(w, message)
+}
+
 // ReplicaHandler exposes replica status
 func ReplicaHandler(w http.ResponseWriter, r *http.Request) {
 	var message string
@@ -166,6 +187,24 @@ func ReplicaHandler(w http.ResponseWriter, r *http.Request) {
 	io.WriteString(w, message)
 }
 
+// ReadOnlyHandler exposes read-only status
+func ReadOnlyHandler(w http.ResponseWriter, r *http.Request) {
+	var message string
+	var status int
+	readOnly, err := backend.IsReadOnly()
+	if err != nil {
+		message = fmt.Sprintf("{\"error\":\"%v\"}", err)
+		status = http.StatusServiceUnavailable
+	}
+	message = fmt.Sprintf("{\"read-only\":%t}", readOnly)
+	status = http.StatusServiceUnavailable
+	if readOnly {
+		status = http.StatusOK
+	}
+	w.WriteHeader(status)
+	io.WriteString(w, message)
+}
+
 // Store TLS ciphers map from string to constant
 // See full list at https://golang.org/pkg/crypto/tls/#pkg-constants
 var tlsCiphers = map[string]uint16{