cortexproject · pracucci · Jun 2, 2020 · Jun 1, 2020 · Jun 1, 2020 · Jun 1, 2020
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -94,6 +94,14 @@
   * TSDB now does memory-mapping of Head chunks and reduces memory usage.
 * [ENHANCEMENT] Experimental TSDB: when `-querier.query-store-after` is configured and running the experimental blocks storage, the time range of the query sent to the store is now manipulated to ensure the query end time is not more recent than 'now - query-store-after'. #2642
 * [ENHANCEMENT] Experimental TSDB: small performance improvement in concurrent usage of RefCache, used during samples ingestion. #2651
+* [ENHANCEMENT] The following endpoints now respond appropriately to an `Accepts` header with the value `application/json` #2673
+  * `/distributor/all_user_stats`
+  * `/distributor/ha_tracker`
+  * `/ingester/ring`
+  * `/store-gateway/ring`
+  * `/compactor/ring`
+  * `/ruler/ring`
+  * `/services`
 * [ENHANCEMENT] Add `-cassandra.num-connections` to allow increasing the number of TCP connections to each Cassandra server. #2666
 * [ENHANCEMENT] Use separate Cassandra clients and connections for reads and writes. #2666
 * [BUGFIX] Ruler: Ensure temporary rule files with special characters are properly mapped and cleaned up. #2506

diff --git a/pkg/cortex/status.go b/pkg/cortex/status.go
@@ -1,18 +1,71 @@
 package cortex
 
 import (
-	"fmt"
+	"html/template"
 	"net/http"
+	"time"
+
+	"github.com/cortexproject/cortex/pkg/util"
 )
 
+const tpl = `
+<!DOCTYPE html>
+<html>
+	<head>
+		<meta charset="UTF-8">
+		<title>Cortex Services Status</title>
+	</head>
+	<body>
+		<h1>Cortex Services Status</h1>
+		<p>Current time: {{ .Now }}</p>
+		<table border="1">
+			<thead>
+				<tr>
+					<th>Service</th>
+					<th>Status</th>
+				</tr>
+			</thead>
+			<tbody>
+				{{ range .Services }}
+				<tr>
+					<td>{{ .Name }}</td>
+					<td>{{ .Status }}</td>
+				</tr>
+				{{ end }}
+			</tbody>
+		</table>
+	</body>
+</html>`
+
+var tmpl *template.Template
+
+type renderService struct {
+	Name   string `json:"name"`
+	Status string `json:"status"`
+}
+
+func init() {
+	tmpl = template.Must(template.New("webpage").Parse(tpl))
+}
+
 func (t *Cortex) servicesHandler(w http.ResponseWriter, r *http.Request) {
 	w.WriteHeader(200)
 	w.Header().Set("Content-Type", "text/plain")
 
-	// TODO: this could be extended to also print sub-services, if given service has any
+	svcs := make([]renderService, 0)
 	for mod, s := range t.ServiceMap {
-		if s != nil {
-			fmt.Fprintf(w, "%v => %v\n", mod, s.State())
-		}
+		svcs = append(svcs, renderService{
+			Name:   mod,
+			Status: s.State().String(),
+		})
 	}
+
+	// TODO: this could be extended to also print sub-services, if given service has any
+	util.RenderHTTPResponse(w, struct {
+		Now      time.Time       `json:"now"`
+		Services []renderService `json:"services"`
+	}{
+		Now:      time.Now(),
+		Services: svcs,
+	}, tmpl, r)
 }
diff --git a/pkg/distributor/ha_tracker_http.go b/pkg/distributor/ha_tracker_http.go
@@ -8,6 +8,8 @@ import (
 	"time"
 
 	"github.com/prometheus/prometheus/pkg/timestamp"
+
+	"github.com/cortexproject/cortex/pkg/util"
 )
 
 const trackerTpl = `
@@ -56,9 +58,12 @@ func init() {
 func (h *haTracker) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	h.electedLock.RLock()
 	type replica struct {
-		UserID, Cluster, Replica string
-		ElectedAt                time.Time
-		UpdateTime, FailoverTime time.Duration
+		UserID       string        `json:"userID"`
+		Cluster      string        `json:"cluster"`
+		Replica      string        `json:"replica"`
+		ElectedAt    time.Time     `json:"electedAt"`
+		UpdateTime   time.Duration `json:"updateDuration"`
+		FailoverTime time.Duration `json:"failoverDuration"`
 	}
 
 	electedReplicas := []replica{}
@@ -86,14 +91,11 @@ func (h *haTracker) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 		return first.Cluster < second.Cluster
 	})
 
-	if err := trackerTmpl.Execute(w, struct {
-		Elected []replica
-		Now     time.Time
+	util.RenderHTTPResponse(w, struct {
+		Elected []replica `json:"elected"`
+		Now     time.Time `json:"now"`
 	}{
 		Elected: electedReplicas,
 		Now:     time.Now(),
-	}); err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
-	}
+	}, trackerTmpl, req)
 }
diff --git a/pkg/distributor/http_admin.go b/pkg/distributor/http_admin.go
@@ -8,6 +8,8 @@ import (
 	"sort"
 	"strings"
 	"time"
+
+	"github.com/cortexproject/cortex/pkg/util"
 )
 
 const tpl = `
@@ -83,16 +85,13 @@ func (d *Distributor) AllUserStatsHandler(w http.ResponseWriter, r *http.Request
 		return
 	}
 
-	if err := tmpl.Execute(w, struct {
-		Now               time.Time
-		Stats             []UserIDStats
-		ReplicationFactor int
+	util.RenderHTTPResponse(w, struct {
+		Now               time.Time     `json:"now"`
+		Stats             []UserIDStats `json:"stats"`
+		ReplicationFactor int           `json:"replicationFactor"`
 	}{
 		Now:               time.Now(),
 		Stats:             stats,
 		ReplicationFactor: d.ingestersRing.ReplicationFactor(),
-	}); err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
-	}
+	}, tmpl, r)
 }
diff --git a/pkg/ring/http.go b/pkg/ring/http.go
@@ -140,10 +140,14 @@ func (r *Ring) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 		}
 
 		ingesters = append(ingesters, struct {
-			ID, State, Address, Timestamp, Zone string
-			Tokens                              []uint32
-			NumTokens                           int
-			Ownership                           float64
+			ID        string   `json:"id"`
+			State     string   `json:"state"`
+			Address   string   `json:"address"`
+			Timestamp string   `json:"timestamp"`
+			Zone      string   `json:"zone"`
+			Tokens    []uint32 `json:"tokens"`
+			NumTokens int      `json:"-"`
+			Ownership float64  `json:"-"`
 		}{
 			ID:        id,
 			State:     state,
@@ -158,16 +162,13 @@ func (r *Ring) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 
 	tokensParam := req.URL.Query().Get("tokens")
 
-	if err := pageTemplate.Execute(w, struct {
-		Ingesters  []interface{}
-		Now        time.Time
-		ShowTokens bool
+	util.RenderHTTPResponse(w, struct {
+		Ingesters  []interface{} `json:"shards"`
+		Now        time.Time     `json:"now"`
+		ShowTokens bool          `json:"-"`
 	}{
 		Ingesters:  ingesters,
 		Now:        time.Now(),
 		ShowTokens: tokensParam == "true",
-	}); err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
-	}
+	}, pageTemplate, req)
 }
diff --git a/pkg/util/http.go b/pkg/util/http.go
@@ -5,8 +5,10 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"html/template"
 	"io"
 	"net/http"
+	"strings"
 
 	"github.com/blang/semver"
 	"github.com/gogo/protobuf/proto"
@@ -29,6 +31,21 @@ func WriteJSONResponse(w http.ResponseWriter, v interface{}) {
 	w.Header().Set("Content-Type", "application/json")
 }
 
+// RenderHTTPResponse either responds with json or a rendered html page using the passed in template
+// by checking the Accepts header
+func RenderHTTPResponse(w http.ResponseWriter, v interface{}, t *template.Template, r *http.Request) {
+	accept := r.Header.Get("Accept")
+	if strings.Contains(accept, "application/json") {
+		WriteJSONResponse(w, v)
+		return
+	}
+
+	err := t.Execute(w, v)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+	}
+}
+
 // CompressionType for encoding and decoding requests and responses.
 type CompressionType int
 

diff --git a/pkg/util/http_test.go b/pkg/util/http_test.go
@@ -0,0 +1,63 @@
+package util
+
+import (
+	"html/template"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRenderHTTPResponse(t *testing.T) {
+	type testStruct struct {
+		Name  string `json:"name"`
+		Value int    `json:"value"`
+	}
+
+	tests := []struct {
+		name     string
+		headers  map[string]string
+		tmpl     string
+		expected string
+		value    testStruct
+	}{
+		{
+			name: "Test Renders json",
+			headers: map[string]string{
+				"Accept": "application/json",
+			},
+			tmpl:     "<html></html>",
+			expected: `{"name":"testName","value":42}`,
+			value: testStruct{
+				Name:  "testName",
+				Value: 42,
+			},
+		},
+		{
+			name:     "Test Renders html",
+			headers:  map[string]string{},
+			tmpl:     "<html>{{ .Name }}</html>",
+			expected: "<html>testName</html>",
+			value: testStruct{
+				Name:  "testName",
+				Value: 42,
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			tmpl := template.Must(template.New("webpage").Parse(tt.tmpl))
+			writer := httptest.NewRecorder()
+			request := httptest.NewRequest("GET", "/", nil)
+
+			for k, v := range tt.headers {
+				request.Header.Add(k, v)
+			}
+
+			RenderHTTPResponse(writer, tt.value, tmpl, request)
+
+			assert.Equal(t, tt.expected, writer.Body.String())
+		})
+	}
+}