Partition the status tab into items in a dropdown

I got feedback from different sources about rules and targets being
too heavy in the status tab if their are lots of them.

This change also allows for more fine-granular locking.

cmd/prometheus/main.go

@@ -103,13 +103,6 @@ func Main() int {
 		flags[f.Name] = f.Value.String()
 	})
 
-	status := &web.PrometheusStatus{
-		TargetPools: targetManager.Pools,
-		Rules:       ruleManager.Rules,
-		Flags:       flags,
-		Birth:       time.Now(),
-	}
-
 	version := &web.PrometheusVersion{
 		Version:   version.Version,
 		Revision:  version.Revision,
@@ -119,9 +112,9 @@ func Main() int {
 		GoVersion: version.GoVersion,
 	}
 
-	webHandler := web.New(memStorage, queryEngine, ruleManager, status, version, &cfg.web)
+	webHandler := web.New(memStorage, queryEngine, targetManager, ruleManager, version, flags, &cfg.web)
 
-	reloadables = append(reloadables, status, targetManager, ruleManager, webHandler, notifier)
+	reloadables = append(reloadables, targetManager, ruleManager, webHandler, notifier)
 
 	if !reloadConfig(cfg.configFile, reloadables...) {
 		return 1

web/api/legacy/query_test.go

@@ -26,7 +26,7 @@ func TestParseTimestampOrNow(t *testing.T) {
 		t.Fatalf("err = %s; want nil", err)
 	}
 	if !testNow().Equal(ts) {
-		t.Fatalf("ts = %v; want ts = %v", ts, testNow)
+		t.Fatalf("ts = %v; want ts = %v", ts, testNow())
 	}
 
 	ts, err = parseTimestampOrNow("1426956073.12345", testNow())

web/ui/templates/_base.html

@@ -39,7 +39,16 @@
             {{ end }}
             <li><a href="{{ pathPrefix }}/alerts">Alerts</a></li>
             <li><a href="{{ pathPrefix }}/graph">Graph</a></li>
-            <li><a href="{{ pathPrefix }}/status">Status</a></li>
+w            <li class="dropdown">
+              <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Status <span class="caret"></span></a>
+              <ul class="dropdown-menu">
+                <li><a href="/status">Runtime &amp; Build Information</a></li>
+                <li><a href="/flags">Command-Line Flags</a></li>
+                <li><a href="/config">Configuration</a></li>
+                <li><a href="/rules">Rules</a></li>
+                <li><a href="/targets">Targets</a></li>
+              </ul>
+            </li>
             <li>
               <a href="https://prometheus.io" target="_blank">Help</a>
             </li>

web/ui/templates/config.html

@@ -0,0 +1,8 @@
+{{define "head"}}<!-- nix -->{{end}}
+
+{{define "content"}}
+  <div class="container-fluid">
+    <h2 id="configuration">Configuration</h2>
+    <pre>{{.}}</pre>
+  </div>
+{{end}}

web/ui/templates/flags.html

@@ -0,0 +1,17 @@
+{{define "head"}}<!-- nix -->{{end}}
+
+{{define "content"}}
+  <div class="container-fluid">
+    <h2 id="startupflags">Command-Line Flags</h2>
+    <table class="table table-condensed table-bordered table-striped table-hover">
+      <tbody>
+        {{range $key, $value := . }}
+        <tr>
+          <th scope="row">{{$key}}</th>
+          <td>{{$value}}</td>
+        </tr>
+        {{end}}
+      </tbody>
+    </table>
+  </div>
+{{end}}

web/ui/templates/rules.html

@@ -0,0 +1,8 @@
+{{define "head"}}<!-- nix -->{{end}}
+
+{{define "content"}}
+  <div class="container-fluid">
+    <h2 id="rules">Rules</h2>
+    <pre>{{range .Rules}}{{.HTMLSnippet pathPrefix}}<br/>{{end}}</pre>
+  </div>
+{{end}}

web/ui/templates/status.html

@@ -7,7 +7,7 @@
       <tbody>
         <tr>
           <th>Uptime</th>
-          <td>{{.Status.Birth.UTC}}</td>
+          <td>{{.Birth.UTC}}</td>
         </tr>
       </tbody>
     </table>
@@ -41,76 +41,5 @@
         </tr>
       </tbody>
     </table>
-
-    <h2 id="configuration">Configuration</h2>
-    <pre>{{.Status.Config}}</pre>
-
-    <h2 id="rules">Rules</h2>
-    <pre>{{range call .Status.Rules}}{{.HTMLSnippet pathPrefix}}<br/>{{end}}</pre>
-
-    <h2 id="targets">Targets</h2>
-      <table class="table table-condensed table-bordered table-striped table-hover">
-        {{range $job, $pool := call .Status.TargetPools}}
-          <thead>
-            <tr><th colspan="5" class="job_header">{{$job}}</th></tr>
-            <tr>
-              <th>Endpoint</th>
-              <th>State</th>
-              <th>Labels</th>
-              <th>Last Scrape</th>
-              <th>Error</th>
-            </tr>
-          </thead>
-          <tbody>
-          {{range $pool}}
-            <tr>
-              <td>
-              <a href="{{.URL | globalURL}}">{{.URL.Scheme}}://{{.URL.Host}}{{.URL.Path}}</a><br>
-                {{range $label, $values := .URL.Query }}
-                  {{range $i, $value := $values}}
-                    <span class="label label-primary">{{$label}}="{{$value}}"</span>
-                  {{end}}
-                {{end}}
-              </td>
-              <td>
-                <span class="alert alert-{{ .Health | healthToClass }} state_indicator text-uppercase">
-                  {{.Health}}
-                </span>
-              </td>
-              <td>
-                <span class="cursor-pointer" data-toggle="tooltip" title="" data-html=true data-original-title="<b>Before relabeling:</b>{{range $k, $v := .MetaLabels}}<br>{{$k | html | html}}=&quot;{{$v | html | html}}&quot;{{end}}">
-                  {{$labels := stripLabels .Labels "job" "instance"}}
-                  {{range $label, $value := $labels}}
-                    <span class="label label-primary">{{$label}}="{{$value}}"</span>
-                  {{else}}
-                    <span class="label label-default">none</span>
-                  {{end}}
-                </span>
-              </td>
-              <td>
-                {{if .LastScrape.IsZero}}Never{{else}}{{since .LastScrape}} ago{{end}}
-              </td>
-              <td>
-                {{if .LastError}}
-                <span class="alert alert-danger state_indicator">{{.LastError}}</span>
-                {{end}}
-              </td>
-            </tr>
-          {{end}}
-          </tbody>
-        {{end}}
-      </table>
-
-    <h2 id="startupflags">Startup Flags</h2>
-    <table class="table table-condensed table-bordered table-striped table-hover">
-      <tbody>
-        {{range $key, $value := .Status.Flags}}
-        <tr>
-          <th scope="row">{{$key}}</th>
-          <td>{{$value}}</td>
-        </tr>
-        {{end}}
-      </tbody>
-    </table>
   </div>
 {{end}}

web/ui/templates/targets.html

@@ -0,0 +1,58 @@
+{{define "head"}}<!-- nix -->{{end}}
+
+{{define "content"}}
+  <div class="container-fluid">
+    <h2 id="targets">Targets</h2>
+      <table class="table table-condensed table-bordered table-striped table-hover">
+        {{range $job, $pool := .Pools}}
+          <thead>
+            <tr><th colspan="5" class="job_header">{{$job}}</th></tr>
+            <tr>
+              <th>Endpoint</th>
+              <th>State</th>
+              <th>Labels</th>
+              <th>Last Scrape</th>
+              <th>Error</th>
+            </tr>
+          </thead>
+          <tbody>
+          {{range $pool}}
+            <tr>
+              <td>
+              <a href="{{.URL | globalURL}}">{{.URL.Scheme}}://{{.URL.Host}}{{.URL.Path}}</a><br>
+                {{range $label, $values := .URL.Query }}
+                  {{range $i, $value := $values}}
+                    <span class="label label-primary">{{$label}}="{{$value}}"</span>
+                  {{end}}
+                {{end}}
+              </td>
+              <td>
+                <span class="alert alert-{{ .Health | healthToClass }} state_indicator text-uppercase">
+                  {{.Health}}
+                </span>
+              </td>
+              <td>
+                <span class="cursor-pointer" data-toggle="tooltip" title="" data-html=true data-original-title="<b>Before relabeling:</b>{{range $k, $v := .MetaLabels}}<br>{{$k | html | html}}=&quot;{{$v | html | html}}&quot;{{end}}">
+                  {{$labels := stripLabels .Labels "job" "instance"}}
+                  {{range $label, $value := $labels}}
+                    <span class="label label-primary">{{$label}}="{{$value}}"</span>
+                  {{else}}
+                    <span class="label label-default">none</span>
+                  {{end}}
+                </span>
+              </td>
+              <td>
+                {{if .LastScrape.IsZero}}Never{{else}}{{since .LastScrape}} ago{{end}}
+              </td>
+              <td>
+                {{if .LastError}}
+                <span class="alert alert-danger state_indicator">{{.LastError}}</span>
+                {{end}}
+              </td>
+            </tr>
+          {{end}}
+          </tbody>
+        {{end}}
+      </table>
+  </div>
+{{end}}

web/web.go

@@ -53,20 +53,23 @@ var localhostRepresentations = []string{"127.0.0.1", "localhost"}
 
 // Handler serves various HTTP endpoints of the Prometheus server
 type Handler struct {
-	ruleManager *rules.Manager
-	queryEngine *promql.Engine
-	storage     local.Storage
+	targetManager *retrieval.TargetManager
+	ruleManager   *rules.Manager
+	queryEngine   *promql.Engine
+	storage       local.Storage
 
 	apiV1     *v1.API
 	apiLegacy *legacy.API
 
-	router      *route.Router
-	listenErrCh chan error
-	quitCh      chan struct{}
-	reloadCh    chan struct{}
-	options     *Options
-	statusInfo  *PrometheusStatus
-	versionInfo *PrometheusVersion
+	router       *route.Router
+	listenErrCh  chan error
+	quitCh       chan struct{}
+	reloadCh     chan struct{}
+	options      *Options
+	configString string
+	versionInfo  *PrometheusVersion
+	birth        time.Time
+	flagsMap     map[string]string
 
 	externalLabels model.LabelSet
 	mtx            sync.RWMutex
@@ -79,38 +82,12 @@ func (h *Handler) ApplyConfig(conf *config.Config) bool {
 	defer h.mtx.Unlock()
 
 	h.externalLabels = conf.GlobalConfig.ExternalLabels
+	h.configString = conf.String()
 
 	return true
 }
 
-// PrometheusStatus contains various information about the status
-// of the running Prometheus process.
-type PrometheusStatus struct {
-	Birth  time.Time
-	Flags  map[string]string
-	Config string
-
-	// A function that returns the current scrape targets pooled
-	// by their job name.
-	TargetPools func() map[string]retrieval.Targets
-	// A function that returns all loaded rules.
-	Rules func() []rules.Rule
-
-	mu sync.RWMutex
-}
-
-// ApplyConfig updates the status state as the new config requires.
-// Returns true on success.
-func (s *PrometheusStatus) ApplyConfig(conf *config.Config) bool {
-	s.mu.Lock()
-	defer s.mu.Unlock()
-
-	s.Config = conf.String()
-
-	return true
-}
-
-// PrometheusVersion contains various build information about Prometheus
+// PrometheusVersion contains build information about Prometheus.
 type PrometheusVersion struct {
 	Version   string `json:"version"`
 	Revision  string `json:"revision"`
@@ -133,7 +110,15 @@ type Options struct {
 }
 
 // New initializes a new web Handler.
-func New(st local.Storage, qe *promql.Engine, rm *rules.Manager, status *PrometheusStatus, version *PrometheusVersion, o *Options) *Handler {
+func New(
+	st local.Storage,
+	qe *promql.Engine,
+	tm *retrieval.TargetManager,
+	rm *rules.Manager,
+	version *PrometheusVersion,
+	flags map[string]string,
+	o *Options,
+) *Handler {
 	router := route.New()
 
 	h := &Handler{
@@ -142,12 +127,14 @@ func New(st local.Storage, qe *promql.Engine, rm *rules.Manager, status *Prometh
 		quitCh:      make(chan struct{}),
 		reloadCh:    make(chan struct{}),
 		options:     o,
-		statusInfo:  status,
 		versionInfo: version,
+		birth:       time.Now(),
+		flagsMap:    flags,
 
-		ruleManager: rm,
-		queryEngine: qe,
-		storage:     st,
+		targetManager: tm,
+		ruleManager:   rm,
+		queryEngine:   qe,
+		storage:       st,
 
 		apiV1: v1.NewAPI(qe, st),
 		apiLegacy: &legacy.API{
@@ -171,10 +158,14 @@ func New(st local.Storage, qe *promql.Engine, rm *rules.Manager, status *Prometh
 	router.Get("/", func(w http.ResponseWriter, r *http.Request) {
 		router.Redirect(w, r, "/graph", http.StatusFound)
 	})
-	router.Get("/graph", instrf("graph", h.graph))
 
-	router.Get("/status", instrf("status", h.status))
 	router.Get("/alerts", instrf("alerts", h.alerts))
+	router.Get("/graph", instrf("graph", h.graph))
+	router.Get("/status", instrf("status", h.status))
+	router.Get("/flags", instrf("flags", h.flags))
+	router.Get("/config", instrf("config", h.config))
+	router.Get("/rules", instrf("rules", h.rules))
+	router.Get("/targets", instrf("targets", h.targets))
 	router.Get("/version", instrf("version", h.version))
 
 	router.Get("/heap", instrf("heap", dumpHeap))
@@ -322,18 +313,34 @@ func (h *Handler) graph(w http.ResponseWriter, r *http.Request) {
 }
 
 func (h *Handler) status(w http.ResponseWriter, r *http.Request) {
-	h.statusInfo.mu.RLock()
-	defer h.statusInfo.mu.RUnlock()
-
 	h.executeTemplate(w, "status.html", struct {
-		Status  *PrometheusStatus
+		Birth   time.Time
 		Version *PrometheusVersion
 	}{
-		Status:  h.statusInfo,
+		Birth:   h.birth,
 		Version: h.versionInfo,
 	})
 }
 
+func (h *Handler) flags(w http.ResponseWriter, r *http.Request) {
+	h.executeTemplate(w, "flags.html", h.flagsMap)
+}
+
+func (h *Handler) config(w http.ResponseWriter, r *http.Request) {
+	h.mtx.RLock()
+	defer h.mtx.RUnlock()
+
+	h.executeTemplate(w, "config.html", h.configString)
+}
+
+func (h *Handler) rules(w http.ResponseWriter, r *http.Request) {
+	h.executeTemplate(w, "rules.html", h.ruleManager)
+}
+
+func (h *Handler) targets(w http.ResponseWriter, r *http.Request) {
+	h.executeTemplate(w, "targets.html", h.targetManager)
+}
+
 func (h *Handler) version(w http.ResponseWriter, r *http.Request) {
 	dec := json.NewEncoder(w)
 	if err := dec.Encode(h.versionInfo); err != nil {