Allow selecting available metrics through UI.

api/api.go

@@ -2,6 +2,7 @@ package api
 
 import (
 	"code.google.com/p/gorest"
+	"github.com/prometheus/prometheus/storage/metric"
 	"github.com/prometheus/prometheus/utility"
 )
 
@@ -10,5 +11,14 @@ type MetricsService struct {
 
 	query      gorest.EndPoint `method:"GET" path:"/query?{expr:string}&{json:string}" output:"string"`
 	queryRange gorest.EndPoint `method:"GET" path:"/query_range?{expr:string}&{end:int64}&{range:int64}&{step:int64}" output:"string"`
+	metrics    gorest.EndPoint `method:"GET" path:"/metrics" output:"string"`
+
+	persistence metric.MetricPersistence
 	time        utility.Time
 }
+
+func NewMetricsService(p metric.MetricPersistence) *MetricsService {
+	return &MetricsService{
+		persistence: p,
+	}
+}

api/query.go

@@ -2,9 +2,11 @@ package api
 
 import (
 	"code.google.com/p/gorest"
+	"encoding/json"
 	"errors"
 	"github.com/prometheus/prometheus/rules"
 	"github.com/prometheus/prometheus/rules/ast"
+	"log"
 	"sort"
 	"time"
 )
@@ -65,3 +67,22 @@ func (serv MetricsService) QueryRange(Expr string, End int64, Range int64, Step
 	sort.Sort(matrix)
 	return ast.TypedValueToJSON(matrix, "matrix")
 }
+
+func (serv MetricsService) Metrics() string {
+	metricNames, err := serv.persistence.GetAllMetricNames()
+	rb := serv.ResponseBuilder()
+	rb.SetContentType(gorest.Application_Json)
+	if err != nil {
+		log.Printf("Error loading metric names: %v", err)
+		rb.SetResponseCode(500)
+		return err.Error()
+	}
+	sort.Strings(metricNames)
+	resultBytes, err := json.Marshal(metricNames)
+	if err != nil {
+		log.Printf("Error marshalling metric names: %v", err)
+		rb.SetResponseCode(500)
+		return err.Error()
+	}
+	return string(resultBytes)
+}

main.go

@@ -49,8 +49,7 @@ func main() {
 
 	persistence, err := leveldb.NewLevelDBMetricPersistence(*metricsStoragePath)
 	if err != nil {
-		log.Print(err)
-		os.Exit(1)
+		log.Fatalf("Error opening storage: %v", err)
 	}
 
 	go func() {
@@ -79,7 +78,7 @@ func main() {
 	}
 
 	go func() {
-		gorest.RegisterService(new(api.MetricsService))
+		gorest.RegisterService(api.NewMetricsService(persistence))
 		exporter := registry.DefaultRegistry.YieldExporter()
 
 		http.Handle("/", gorest.Handle())

static/graph.html

@@ -22,7 +22,12 @@
         <div class="grouping_box">
           <form action="/api/query_range" method="GET" class="query_form">
             <label for="expr{{id}}">Expression:</label>
-            <input type="text" name="expr" id="expr{{id}}" size="80" value="{{expr}}"><br>
+            <input type="text" name="expr" id="expr{{id}}" size="80" value="{{expr}}">
+            <select name="insert_metric">
+                <option value="">- Insert Metric -</option>
+            </select>
+
+            <br>
 
             <label for="range_input{{id}}">Range:</label>
             <input type="button" value="-" name="dec_range">

static/js/graph.js

@@ -69,6 +69,7 @@ Prometheus.Graph.prototype.initialize = function() {
   self.expr = graphWrapper.find("input[name=expr]");
   self.rangeInput = self.queryForm.find("input[name=range_input]");
   self.stacked = self.queryForm.find("input[name=stacked]");
+  self.insertMetric = self.queryForm.find("select[name=insert_metric]");
 
   self.graph = graphWrapper.find(".graph");
   self.legend = graphWrapper.find(".legend");
@@ -81,18 +82,40 @@ Prometheus.Graph.prototype.initialize = function() {
 
   self.queryForm.find("input[name=inc_range]").click(function() { self.increaseRange(); });
   self.queryForm.find("input[name=dec_range]").click(function() { self.decreaseRange(); });
+  self.insertMetric.change(function() {
+      self.expr.val(self.expr.val() + self.insertMetric.val());
+  });
   self.expr.focus(); // TODO: move to external Graph method.
 
+  self.populateInsertableMetrics();
+
   if (self.expr.val()) {
     self.submitQuery();
   }
 };
 
+Prometheus.Graph.prototype.populateInsertableMetrics = function() {
+  var self = this;
+  $.ajax({
+      method: "GET",
+      url: "/api/metrics",
+      dataType: "json",
+      success: function(json, textStatus) {
+        for (var i = 0; i < json.length; i++) {
+          self.insertMetric[0].options.add(new Option(json[i], json[i]));
+        }
+      },
+      error: function() {
+        alert("Error loading available metrics!");
+      },
+  });
+};
+
 Prometheus.Graph.prototype.onChange = function(handler) {
   this.changeHandler = handler;
 };
 
-Prometheus.Graph.prototype.getOptions = function(handler) {
+Prometheus.Graph.prototype.getOptions = function() {
   var self = this;
   var options = {};
 
@@ -306,8 +329,6 @@ function storeGraphOptionsInUrl(options) {
   var allGraphsOptions = [];
   for (var i = 0; i < graphs.length; i++) {
     allGraphsOptions.push(graphs[i].getOptions());
-    console.log(graphs[i].id);
-    console.log(graphs[i].getOptions());
   }
   var optionsJSON = JSON.stringify(allGraphsOptions);
   window.location.hash = encodeURIComponent(optionsJSON);