Add all-nodes api endpoint for system view

api.go

@@ -232,6 +232,79 @@ func handleWrite(rw http.ResponseWriter, r *http.Request) {
 	rw.WriteHeader(http.StatusOK)
 }
 
+func handleAllNodes(rw http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	clusterId := vars["cluster"]
+	from, err := strconv.ParseInt(vars["from"], 10, 64)
+	if err != nil {
+		http.Error(rw, err.Error(), http.StatusBadRequest)
+		return
+	}
+	to, err := strconv.ParseInt(vars["to"], 10, 64)
+	if err != nil {
+		http.Error(rw, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	if r.Method != http.MethodPost {
+		http.Error(rw, "Method Not Allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	bodyDec := json.NewDecoder(r.Body)
+	var reqBody struct {
+		Metrics []string `json:"metrics"`
+	}
+	err = bodyDec.Decode(&reqBody)
+	if err != nil {
+		http.Error(rw, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	res := make(map[string]map[string]ApiMetricData)
+
+	memoryStore.root.lock.RLock()
+	cluster, ok := memoryStore.root.children[clusterId]
+	memoryStore.root.lock.RUnlock()
+	if !ok {
+		http.Error(rw, fmt.Sprintf("cluster '%s' does not exist", clusterId), http.StatusBadRequest)
+		return
+	}
+
+	cluster.lock.RLock()
+	hosts := make([]string, 0, len(cluster.children))
+	for host := range cluster.children {
+		hosts = append(hosts, host)
+	}
+	cluster.lock.RUnlock()
+
+	for _, host := range hosts {
+		metrics := make(map[string]ApiMetricData)
+		for _, metric := range reqBody.Metrics {
+			data, f, t, err := memoryStore.Read(Selector{SelectorElement{String: clusterId}, SelectorElement{String: host}}, metric, from, to)
+			if err != nil {
+				// http.Error(rw, err.Error(), http.StatusInternalServerError)
+				msg := err.Error()
+				metrics[metric] = ApiMetricData{Error: &msg}
+				continue
+			}
+
+			metrics[metric] = ApiMetricData{
+				From: f,
+				To:   t,
+				Data: data,
+			}
+		}
+		res[host] = metrics
+	}
+
+	rw.Header().Set("Content-Type", "application/json")
+	err = json.NewEncoder(rw).Encode(res)
+	if err != nil {
+		log.Println(err.Error())
+	}
+}
+
 func authentication(next http.Handler, publicKey ed25519.PublicKey) http.Handler {
 	return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
 		authheader := r.Header.Get("Authorization")
@@ -268,6 +341,7 @@ func StartApiServer(address string, ctx context.Context) error {
 	r.HandleFunc("/api/{from:[0-9]+}/{to:[0-9]+}/stats", handleStats)
 	r.HandleFunc("/api/{to:[0-9]+}/free", handleFree)
 	r.HandleFunc("/api/{cluster}/peek", handlePeek)
+	r.HandleFunc("/api/{cluster}/{from:[0-9]+}/{to:[0-9]+}/all-nodes", handleAllNodes)
 	r.HandleFunc("/api/write", handleWrite)
 
 	server := &http.Server{

selector.go

@@ -6,13 +6,23 @@ import (
 )
 
 type SelectorElement struct {
+	Any    bool
 	String string
 	Group  []string
 }
 
 func (se *SelectorElement) UnmarshalJSON(input []byte) error {
 	if input[0] == '"' {
-		return json.Unmarshal(input, &se.String)
+		if err := json.Unmarshal(input, &se.String); err != nil {
+			return err
+		}
+
+		if se.String == "*" {
+			se.Any = true
+			se.String = ""
+		}
+
+		return nil
 	}
 
 	if input[0] == '[' {
@@ -23,6 +33,10 @@ func (se *SelectorElement) UnmarshalJSON(input []byte) error {
 }
 
 func (se *SelectorElement) MarshalJSON() ([]byte, error) {
+	if se.Any {
+		return []byte("\"*\""), nil
+	}
+
 	if se.String != "" {
 		return json.Marshal(se.String)
 	}
@@ -91,5 +105,13 @@ func (l *level) findBuffers(selector Selector, offset int, f func(b *buffer) err
 		return nil
 	}
 
+	if sel.Any && l.children != nil {
+		for _, lvl := range l.children {
+			if err := lvl.findBuffers(selector[1:], offset, f); err != nil {
+				return err
+			}
+		}
+	}
+
 	panic("impossible")
 }