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Allow custom status page templates #144

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Allow custom status page templates #144

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8f5b218
Allow custom status page templates
colega Mar 25, 2022
f17ef29
Reformat HTML
colega Mar 25, 2022
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158 changes: 10 additions & 148 deletions kv/memberlist/kv_init_service.go
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Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,7 @@ package memberlist

import (
"context"
_ "embed"
"encoding/json"
"fmt"
"html/template"
Expand Down Expand Up @@ -157,7 +158,7 @@ func (kvs *KVInitService) ServeHTTP(w http.ResponseWriter, req *http.Request) {

sent, received := kv.getSentAndReceivedMessages()

v := pageData{
v := statusPageData{
Now: time.Now(),
Memberlist: kv.memberlist,
SortedMembers: members,
Expand All @@ -183,7 +184,7 @@ func (kvs *KVInitService) ServeHTTP(w http.ResponseWriter, req *http.Request) {
return
}

err := pageTemplate.Execute(w, v)
err := defaultPageTemplate.Execute(w, v)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
Expand Down Expand Up @@ -276,7 +277,9 @@ func downloadKey(w http.ResponseWriter, kv *KV, store map[string]valueDesc, key
_, _ = w.Write(encoded)
}

type pageData struct {
// statusPageData is the root element of the status page served through HTTP.
// Depending on the accepted content-type, it will be either marshaled as JSON or provided to the rendered HTML template.
type statusPageData struct {
Now time.Time
Memberlist *memberlist.Memberlist
SortedMembers []*memberlist.Node
Expand All @@ -285,149 +288,8 @@ type pageData struct {
ReceivedMessages []message
}

var pageTemplate = template.Must(template.New("webpage").Funcs(template.FuncMap{
//go:embed status.gohtml
var defaultPageContent string
var defaultPageTemplate = template.Must(template.New("webpage").Funcs(template.FuncMap{
"StringsJoin": strings.Join,
}).Parse(pageContent))

const pageContent = `
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Memberlist Status</title>
</head>
<body>
<h1>Memberlist Status</h1>
<p>Current time: {{ .Now }}</p>

<ul>
<li>Health Score: {{ .Memberlist.GetHealthScore }} (lower = better, 0 = healthy)</li>
<li>Members: {{ .Memberlist.NumMembers }}</li>
</ul>

<h2>KV Store</h2>

<table width="100%" border="1">
<thead>
<tr>
<th>Key</th>
<th>Value Details</th>
<th>Actions</th>
</tr>
</thead>

<tbody>
{{ range $k, $v := .Store }}
<tr>
<td>{{ $k }}</td>
<td>{{ $v }}</td>
<td>
<a href="?viewKey={{ $k }}&format=json">json</a>
| <a href="?viewKey={{ $k }}&format=json-pretty">json-pretty</a>
| <a href="?viewKey={{ $k }}&format=struct">struct</a>
| <a href="?downloadKey={{ $k }}">download</a>
</td>
</tr>
{{ end }}
</tbody>
</table>

<p>Note that value "version" is node-specific. It starts with 0 (on restart), and increases on each received update. Size is in bytes.</p>

<h2>Memberlist Cluster Members</h2>

<table width="100%" border="1">
<thead>
<tr>
<th>Name</th>
<th>Address</th>
<th>State</th>
</tr>
</thead>

<tbody>
{{ range .SortedMembers }}
<tr>
<td>{{ .Name }}</td>
<td>{{ .Address }}</td>
<td>{{ .State }}</td>
</tr>
{{ end }}
</tbody>
</table>

<p>State: 0 = Alive, 1 = Suspect, 2 = Dead, 3 = Left</p>

<h2>Received Messages</h2>

<a href="?deleteMessages=true">Delete All Messages (received and sent)</a>

<table width="100%" border="1">
<thead>
<tr>
<th>ID</th>
<th>Time</th>
<th>Key</th>
<th>Value in the Message</th>
<th>Version After Update (0 = no change)</th>
<th>Changes</th>
<th>Actions</th>
</tr>
</thead>

<tbody>
{{ range .ReceivedMessages }}
<tr>
<td>{{ .ID }}</td>
<td>{{ .Time.Format "15:04:05.000" }}</td>
<td>{{ .Pair.Key }}</td>
<td>size: {{ .Pair.Value | len }}, codec: {{ .Pair.Codec }}</td>
<td>{{ .Version }}</td>
<td>{{ StringsJoin .Changes ", " }}</td>
<td>
<a href="?viewMsg={{ .ID }}&format=json">json</a>
| <a href="?viewMsg={{ .ID }}&format=json-pretty">json-pretty</a>
| <a href="?viewMsg={{ .ID }}&format=struct">struct</a>
</td>
</tr>
{{ end }}
</tbody>
</table>

<h2>Sent Messages</h2>

<a href="?deleteMessages=true">Delete All Messages (received and sent)</a>

<table width="100%" border="1">
<thead>
<tr>
<th>ID</th>
<th>Time</th>
<th>Key</th>
<th>Value</th>
<th>Version</th>
<th>Changes</th>
<th>Actions</th>
</tr>
</thead>

<tbody>
{{ range .SentMessages }}
<tr>
<td>{{ .ID }}</td>
<td>{{ .Time.Format "15:04:05.000" }}</td>
<td>{{ .Pair.Key }}</td>
<td>size: {{ .Pair.Value | len }}, codec: {{ .Pair.Codec }}</td>
<td>{{ .Version }}</td>
<td>{{ StringsJoin .Changes ", " }}</td>
<td>
<a href="?viewMsg={{ .ID }}&format=json">json</a>
| <a href="?viewMsg={{ .ID }}&format=json-pretty">json-pretty</a>
| <a href="?viewMsg={{ .ID }}&format=struct">struct</a>
</td>
</tr>
{{ end }}
</tbody>
</table>
</body>
</html>`
}).Parse(defaultPageContent))
2 changes: 1 addition & 1 deletion kv/memberlist/kv_init_service_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -21,7 +21,7 @@ func TestPage(t *testing.T) {
_ = ml.Shutdown()
})

require.NoError(t, pageTemplate.Execute(&bytes.Buffer{}, pageData{
require.NoError(t, defaultPageTemplate.Execute(&bytes.Buffer{}, statusPageData{
Now: time.Now(),
Memberlist: ml,
SortedMembers: ml.Members(),
Expand Down
5 changes: 5 additions & 0 deletions kv/memberlist/memberlist_client.go
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Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,7 @@ import (
"errors"
"flag"
"fmt"
"html/template"
"math"
"strings"
"sync"
Expand Down Expand Up @@ -164,6 +165,10 @@ type KVConfig struct {

// Codecs to register. Codecs need to be registered before joining other members.
Codecs []codec.Codec `yaml:"-"`

// CustomHTTPHandlerTemplate will be rendered by HTTPHandler instead of the embedded default one, if provided.
// This option is set internally and never exposed to the user.
CustomHTTPHandlerTemplate *template.Template `yaml:"-"`
}

// RegisterFlagsWithPrefix registers flags.
Expand Down
143 changes: 143 additions & 0 deletions kv/memberlist/status.gohtml
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Original file line number Diff line number Diff line change
@@ -0,0 +1,143 @@
{{- /*gotype: github.com/grafana/dskit/kv/memberlist.statusPageData */ -}}
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Memberlist Status</title>
</head>
<body>
<h1>Memberlist Status</h1>
<p>Current time: {{ .Now }}</p>

<ul>
<li>Health Score: {{ .Memberlist.GetHealthScore }} (lower = better, 0 = healthy)</li>
<li>Members: {{ .Memberlist.NumMembers }}</li>
</ul>

<h2>KV Store</h2>

<table width="100%" border="1">
<thead>
<tr>
<th>Key</th>
<th>Value Details</th>
<th>Actions</th>
</tr>
</thead>

<tbody>
{{ range $k, $v := .Store }}
<tr>
<td>{{ $k }}</td>
<td>{{ $v }}</td>
<td>
<a href="?viewKey={{ $k }}&format=json">json</a>
| <a href="?viewKey={{ $k }}&format=json-pretty">json-pretty</a>
| <a href="?viewKey={{ $k }}&format=struct">struct</a>
| <a href="?downloadKey={{ $k }}">download</a>
</td>
</tr>
{{ end }}
</tbody>
</table>

<p>Note that value "version" is node-specific. It starts with 0 (on restart), and increases on each received update.
Size is in bytes.</p>

<h2>Memberlist Cluster Members</h2>

<table width="100%" border="1">
<thead>
<tr>
<th>Name</th>
<th>Address</th>
<th>State</th>
</tr>
</thead>

<tbody>
{{ range .SortedMembers }}
<tr>
<td>{{ .Name }}</td>
<td>{{ .Address }}</td>
<td>{{ .State }}</td>
</tr>
{{ end }}
</tbody>
</table>

<p>State: 0 = Alive, 1 = Suspect, 2 = Dead, 3 = Left</p>

<h2>Received Messages</h2>

<a href="?deleteMessages=true">Delete All Messages (received and sent)</a>

<table width="100%" border="1">
<thead>
<tr>
<th>ID</th>
<th>Time</th>
<th>Key</th>
<th>Value in the Message</th>
<th>Version After Update (0 = no change)</th>
<th>Changes</th>
<th>Actions</th>
</tr>
</thead>

<tbody>
{{ range .ReceivedMessages }}
<tr>
<td>{{ .ID }}</td>
<td>{{ .Time.Format "15:04:05.000" }}</td>
<td>{{ .Pair.Key }}</td>
<td>size: {{ .Pair.Value | len }}, codec: {{ .Pair.Codec }}</td>
<td>{{ .Version }}</td>
<td>{{ StringsJoin .Changes ", " }}</td>
<td>
<a href="?viewMsg={{ .ID }}&format=json">json</a>
| <a href="?viewMsg={{ .ID }}&format=json-pretty">json-pretty</a>
| <a href="?viewMsg={{ .ID }}&format=struct">struct</a>
</td>
</tr>
{{ end }}
</tbody>
</table>

<h2>Sent Messages</h2>

<a href="?deleteMessages=true">Delete All Messages (received and sent)</a>

<table width="100%" border="1">
<thead>
<tr>
<th>ID</th>
<th>Time</th>
<th>Key</th>
<th>Value</th>
<th>Version</th>
<th>Changes</th>
<th>Actions</th>
</tr>
</thead>

<tbody>
{{ range .SentMessages }}
<tr>
<td>{{ .ID }}</td>
<td>{{ .Time.Format "15:04:05.000" }}</td>
<td>{{ .Pair.Key }}</td>
<td>size: {{ .Pair.Value | len }}, codec: {{ .Pair.Codec }}</td>
<td>{{ .Version }}</td>
<td>{{ StringsJoin .Changes ", " }}</td>
<td>
<a href="?viewMsg={{ .ID }}&format=json">json</a>
| <a href="?viewMsg={{ .ID }}&format=json-pretty">json-pretty</a>
| <a href="?viewMsg={{ .ID }}&format=struct">struct</a>
</td>
</tr>
{{ end }}
</tbody>
</table>
</body>
</html>
6 changes: 5 additions & 1 deletion ring/basic_lifecycler.go
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Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,7 @@ package ring
import (
"context"
"fmt"
"html/template"
"net/http"
"sort"
"sync"
Expand Down Expand Up @@ -55,6 +56,9 @@ type BasicLifecyclerConfig struct {
// If true lifecycler doesn't unregister instance from the ring when it's stopping. Default value is false,
// which means unregistering.
KeepInstanceInTheRingOnShutdown bool

// CustomHTTPHandlerTemplate will be rendered by HTTPHandler instead of the embedded default one, if provided.
CustomHTTPHandlerTemplate *template.Template
}

// BasicLifecycler is a basic ring lifecycler which allows to hook custom
Expand Down Expand Up @@ -507,5 +511,5 @@ func (l *BasicLifecycler) getRing(ctx context.Context) (*Desc, error) {
}

func (l *BasicLifecycler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
newRingPageHandler(l, l.cfg.HeartbeatPeriod).handle(w, req)
newRingPageHandler(l, l.cfg.HeartbeatPeriod, l.cfg.CustomHTTPHandlerTemplate).handle(w, req)
}
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