pkg/debug: implement control panel

Control Panel allows to control different chores and services.
Currently this adds controlling of cycles.

Change-Id: I734f1676b2a0d883b8f5ba937e93c45ac1a9ce21
This commit is contained in:
Egon Elbre 2020-01-29 10:37:12 -05:00
parent f237d70098
commit a2b2bc676b
3 changed files with 213 additions and 5 deletions

193
pkg/debug/panel.go Normal file
View File

@ -0,0 +1,193 @@
// Copyright (C) 2020 Storj Labs, Inc.
// See LICENSE for copying information.
package debug
import (
"fmt"
"io"
"net/http"
"path"
"sort"
"strings"
"sync"
"text/template"
"unicode"
"go.uber.org/zap"
"storj.io/common/sync2"
)
// Panel implements a serving of customized callbacks.
type Panel struct {
log *zap.Logger
url string
mu sync.RWMutex
lookup map[string]*Button
categories []*ButtonGroup
}
// NewPanel creates a new panel.
func NewPanel(log *zap.Logger, url string) *Panel {
return &Panel{
log: log,
url: url,
lookup: map[string]*Button{},
}
}
// ButtonGroup contains description of a collection of buttons.
type ButtonGroup struct {
Slug string
Name string
Buttons []*Button
}
// Button defines a clickable button.
type Button struct {
Slug string
Name string
Call func(progress io.Writer) error
}
// Add adds a button group to the panel.
func (panel *Panel) Add(cat *ButtonGroup) {
panel.mu.Lock()
defer panel.mu.Unlock()
if cat.Slug == "" {
cat.Slug = slugify(cat.Name)
}
for _, but := range cat.Buttons {
but.Slug = slugify(but.Name)
panel.lookup["/"+path.Join(cat.Slug, but.Slug)] = but
}
panel.categories = append(panel.categories, cat)
sort.Slice(panel.categories, func(i, k int) bool {
return panel.categories[i].Name < panel.categories[k].Name
})
}
// ServeHTTP serves buttons on the prefix and on
// other endpoints calls the specified call.
func (panel *Panel) ServeHTTP(w http.ResponseWriter, r *http.Request) {
panel.mu.RLock()
defer panel.mu.RUnlock()
url := strings.TrimPrefix(r.URL.Path, panel.url)
if len(url) >= len(r.URL.Path) {
http.Error(w, "not found", http.StatusNotFound)
return
}
if url == "/" {
err := buttonsTemplate.Execute(w, map[string]interface{}{
"URL": panel.url,
"Categories": panel.categories,
})
if err != nil {
panel.log.Error("buttons template failed", zap.Error(err))
}
return
}
button, ok := panel.lookup[url]
if !ok {
http.Error(w, "control not found", http.StatusNotFound)
return
}
panel.log.Debug("calling", zap.String("url", url))
w.Header().Add("Content-Type", "text/plain")
w.Header().Add("Cache-Control", "no-cache")
w.Header().Add("Cache-Control", "max-age=0")
err := button.Call(w)
if err != nil {
panel.log.Error("failed to run button", zap.String("url", url), zap.Error(err))
}
}
var buttonsTemplate = template.Must(template.New("").Parse(`<!DOCTYPE html>
<html>
<head>
<title>Control Panel</title>
<style>
.button {
padding: 0.8rem 1rem;
border: 1px solid #ccc;
margin: 0.1px;
}
.button:hover {
background: #eee;
}
</style>
</head>
<body>
<h1>Control Panel</h1>
{{ $url := .URL }}
{{ range $cat := .Categories }}
<div class="category">
<h2>{{$cat.Name}}</h2>
{{ range $but := $cat.Buttons }}
<a class="button" href="{{$url}}/{{$cat.Slug}}/{{$but.Slug}}">{{.Name}}</a>
{{ end }}
</div>
{{ end }}
</body>
</html>`))
// slugify converts text to a slug
func slugify(s string) string {
return strings.Map(func(r rune) rune {
switch {
case 'a' <= r && r <= 'z':
return r
case 'A' <= r && r <= 'Z':
return unicode.ToLower(r)
case '0' <= r && r <= '9':
return r
default:
return '-'
}
}, s)
}
// Cycle returns button group for a cycle
func Cycle(name string, cycle *sync2.Cycle) *ButtonGroup {
return &ButtonGroup{
Name: name,
Buttons: []*Button{
{
Name: "Trigger",
Call: func(w io.Writer) error {
_, _ = fmt.Fprintln(w, "Triggering")
cycle.TriggerWait()
_, _ = fmt.Fprintln(w, "Done")
return nil
},
}, {
Name: "Pause",
Call: func(w io.Writer) error {
cycle.Pause()
_, _ = fmt.Fprintln(w, "Paused")
return nil
},
}, {
Name: "Resume",
Call: func(w io.Writer) error {
cycle.Restart()
_, _ = fmt.Fprintln(w, "Resumed")
return nil
},
},
},
}
}

View File

@ -31,6 +31,8 @@ func init() {
// Config defines configuration for debug server.
type Config struct {
Address string `internal:"true"`
Control bool `help:"expose control panel" releaseDefault:"false" devDefault:"true"`
}
// Server provides endpoints for debugging.
@ -41,10 +43,12 @@ type Server struct {
server http.Server
mux http.ServeMux
Panel *Panel
registry *monkit.Registry
}
// NewServer returns a new debug.Server
// NewServer returns a new debug.Server.
func NewServer(log *zap.Logger, listener net.Listener, registry *monkit.Registry, config Config) *Server {
server := &Server{log: log}
@ -52,6 +56,13 @@ func NewServer(log *zap.Logger, listener net.Listener, registry *monkit.Registry
server.server.Handler = &server.mux
server.registry = registry
server.Panel = NewPanel(log.Named("control"), "/control")
if config.Control {
server.mux.Handle("/control/", server.Panel)
}
server.mux.Handle("/version/", http.StripPrefix("/version", checker.NewDebugHandler(log.Named("version"))))
server.mux.HandleFunc("/debug/pprof/", pprof.Index)
server.mux.HandleFunc("/debug/pprof/cmdline", pprof.Cmdline)
server.mux.HandleFunc("/debug/pprof/profile", pprof.Profile)
@ -60,9 +71,9 @@ func NewServer(log *zap.Logger, listener net.Listener, registry *monkit.Registry
server.mux.HandleFunc("/debug/run/trace/db", server.collectTraces)
server.mux.Handle("/version/", http.StripPrefix("/version", checker.NewDebugHandler(log.Named("version"))))
server.mux.Handle("/mon/", http.StripPrefix("/mon", present.HTTP(server.registry)))
server.mux.HandleFunc("/metrics", server.metrics)
server.mux.HandleFunc("/health", func(w http.ResponseWriter, r *http.Request) {
_, _ = fmt.Fprintln(w, "OK")
})
@ -89,13 +100,13 @@ func (server *Server) Run(ctx context.Context) error {
return group.Wait()
}
// Close closes server and underlying listener
// Close closes server and underlying listener.
func (server *Server) Close() error {
return Error.Wrap(server.server.Close())
}
// metrics writes https://prometheus.io/docs/instrumenting/exposition_formats/
func (server *Server) metrics(w http.ResponseWriter, r *http.Request) {
// writes https://prometheus.io/docs/instrumenting/exposition_formats/
// TODO(jt): deeper monkit integration so we can expose prometheus types
// (https://prometheus.io/docs/concepts/metric_types/)
server.registry.Stats(func(name string, val float64) {
@ -105,7 +116,7 @@ func (server *Server) metrics(w http.ResponseWriter, r *http.Request) {
})
}
// collectTraces
// collectTraces collects traces until request is canceled.
func (server *Server) collectTraces(w http.ResponseWriter, r *http.Request) {
cancel := traces.CollectTraces()
defer cancel()
@ -118,6 +129,7 @@ func (server *Server) collectTraces(w http.ResponseWriter, r *http.Request) {
}
}
// sanitize formats val to be suitable for prometheus.
func sanitize(val string) string {
// https://prometheus.io/docs/concepts/data_model/
// specifies all metric names must match [a-zA-Z_:][a-zA-Z0-9_:]*

View File

@ -100,6 +100,9 @@ contact.external-address: ""
# address to listen on for debug endpoints
# debug.addr: 127.0.0.1:0
# expose control panel
# debug.control: false
# If set, a path to write a process trace SVG to
# debug.trace-out: ""