cortexproject · tomwilkie · Nov 25, 2016 · Nov 25, 2016 · Nov 25, 2016
diff --git a/cmd/cortex/main.go b/cmd/cortex/main.go
@@ -147,6 +147,8 @@ func main() {
 	defer r.Stop()
 
 	router := mux.NewRouter()
+	router.Handle("/ring", r)
+
 	switch cfg.mode {
 	case modeDistributor:
 		cfg.distributorConfig.Ring = r

diff --git a/ring/http.go b/ring/http.go
@@ -0,0 +1,102 @@
+package ring
+
+import (
+	"fmt"
+	"html/template"
+	"net/http"
+	"time"
+)
+
+const tpl = `
+<!DOCTYPE html>
+<html>
+	<head>
+		<meta charset="UTF-8">
+		<title>Cortex Ring Status</title>
+	</head>
+	<body>
+		<h1>Cortex Ring Status</h1>
+		<p>Current time: {{ .Now }}</p>
+		<p>{{ .Message }}</p>
+		<form action="" method="POST">
+			<table width="100%" border="1">
+				<thead>
+					<tr>
+						<th>Ingester</th>
+						<th>State</th>
+						<th>Address</th>
+						<th>Last Heartbeat</th>
+						<th>Actions</th>
+					</tr>
+				</thead>
+				<tbody>
+					{{ range $key, $value := .Ring.Ingesters }}
+					<tr>
+						<td>{{ $key }}</td>
+						<td>{{ $value.State }}</td>
+						<td>{{ $value.Hostname }}</td>
+						<td>{{ $value.Timestamp | time }}</td>
+						<td><button name="forget" value="{{ $key }}" type="submit">Forget</button></td>
+					</tr>
+					{{ end }}
+				</tbody>
+			</table>
+		</form>
+	</body>
+</html>`
+
+var tmpl *template.Template
+
+func init() {
+	var err error
+	tmpl, err = template.New("webpage").
+		Funcs(template.FuncMap{
+			"time": func(in interface{}) string {
+				return in.(time.Time).String()
+			},
+		}).
+		Parse(tpl)
+	if err != nil {
+		panic(err)
+	}
+}
+
+func (r *Ring) forget(id string) error {
+	unregister := func(in interface{}) (out interface{}, retry bool, err error) {
+		if in == nil {
+			return nil, false, fmt.Errorf("found empty ring when trying to unregister")
+		}
+
+		ringDesc := in.(*Desc)
+		ringDesc.removeIngester(id)
+		return ringDesc, true, nil
+	}
+	return r.consul.CAS(consulKey, descFactory, unregister)
+}
+
+func (r *Ring) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	message := ""
+	if req.Method == http.MethodPost {
+		ingesterID := req.FormValue("forget")
+		if err := r.forget(ingesterID); err != nil {
+			message = fmt.Sprintf("Error forgetting ingester: %v", err)
+		} else {
+			message = fmt.Sprintf("Ingester %s forgotten", ingesterID)
+		}
+	}
+
+	r.mtx.RLock()
+	defer r.mtx.RUnlock()
+	if err := tmpl.Execute(w, struct {
+		Ring    Desc
+		Message string
+		Now     time.Time
+	}{
+		Ring:    r.ringDesc,
+		Message: message,
+		Now:     time.Now(),
+	}); err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+}
diff --git a/ring/ingester_lifecycle.go b/ring/ingester_lifecycle.go
@@ -99,7 +99,7 @@ func (r *IngesterRegistration) Unregister() {
 func (r *IngesterRegistration) loop() {
 	defer r.wait.Done()
 	tokens := r.pickTokens()
-	defer r.unregister(tokens)
+	defer r.unregister()
 	r.heartbeat(tokens)
 }
 
@@ -176,14 +176,14 @@ func (r *IngesterRegistration) heartbeat(tokens []uint32) {
 	}
 }
 
-func (r *IngesterRegistration) unregister(tokens []uint32) {
+func (r *IngesterRegistration) unregister() {
 	unregister := func(in interface{}) (out interface{}, retry bool, err error) {
 		if in == nil {
 			return nil, false, fmt.Errorf("found empty ring when trying to unregister")
 		}
 
 		ringDesc := in.(*Desc)
-		ringDesc.removeIngester(r.id, tokens)
+		ringDesc.removeIngester(r.id)
 		return ringDesc, true, nil
 	}
 	if err := r.consul.CAS(consulKey, descFactory, unregister); err != nil {

diff --git a/ring/model.go b/ring/model.go
@@ -3,8 +3,6 @@ package ring
 import (
 	"sort"
 	"time"
-
-	"github.com/prometheus/common/log"
 )
 
 // IngesterState describes the state of an ingester
@@ -83,29 +81,13 @@ func (d *Desc) addIngester(id, hostname, grpcHostname string, tokens []uint32, s
 	sort.Sort(d.Tokens)
 }
 
-func (d *Desc) removeIngester(id string, tokens []uint32) {
+func (d *Desc) removeIngester(id string) {
 	delete(d.Ingesters, id)
 	output := []TokenDesc{}
-	i, j := 0, 0
-	for i < len(d.Tokens) && j < len(tokens) {
-		if d.Tokens[i].Token < tokens[j] {
+	for i := 0; i < len(d.Tokens); i++ {
+		if d.Tokens[i].Ingester != id {
 			output = append(output, d.Tokens[i])
-			i++
-		} else if d.Tokens[i].Token > tokens[j] {
-			log.Infof("Missing token from ring: %d", tokens[j])
-			j++
-		} else {
-			i++
-			j++
 		}
 	}
-	for i < len(d.Tokens) {
-		output = append(output, d.Tokens[i])
-		i++
-	}
-	for j < len(tokens) {
-		log.Infof("Missing token from ring: %d", tokens[j])
-		j++
-	}
 	d.Tokens = output
 }
diff --git a/ring/ring.go b/ring/ring.go
@@ -35,15 +35,9 @@ func (x uint32s) Swap(i, j int)      { x[i], x[j] = x[j], x[i] }
 // ErrEmptyRing is the error returned when trying to get an element when nothing has been added to hash.
 var ErrEmptyRing = errors.New("empty circle")
 
-// CoordinationStateClient is an interface to getting changes to the coordination
-// state.  Should allow us to swap out Consul for something else (mesh?) later.
-type CoordinationStateClient interface {
-	WatchKey(key string, factory InstanceFactory, done <-chan struct{}, f func(interface{}) bool)
-}
-
 // Ring holds the information about the members of the consistent hash circle.
 type Ring struct {
-	client           CoordinationStateClient
+	consul           ConsulClient
 	quit, done       chan struct{}
 	heartbeatTimeout time.Duration
 
@@ -56,9 +50,9 @@ type Ring struct {
 }
 
 // New creates a new Ring
-func New(client CoordinationStateClient, heartbeatTimeout time.Duration) *Ring {
+func New(consul ConsulClient, heartbeatTimeout time.Duration) *Ring {
 	r := &Ring{
-		client:           client,
+		consul:           consul,
 		heartbeatTimeout: heartbeatTimeout,
 		quit:             make(chan struct{}),
 		done:             make(chan struct{}),
@@ -90,7 +84,7 @@ func (r *Ring) Stop() {
 
 func (r *Ring) loop() {
 	defer close(r.done)
-	r.client.WatchKey(consulKey, descFactory, r.quit, func(value interface{}) bool {
+	r.consul.WatchKey(consulKey, descFactory, r.quit, func(value interface{}) bool {
 		if value == nil {
 			log.Infof("Ring doesn't exist in consul yet.")
 			return true