prometheus/web/web.go

191 lines
5.0 KiB
Go

// Copyright 2013 Prometheus Team
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package web
import (
"flag"
"fmt"
"html/template"
"io/ioutil"
"net"
"net/http"
_ "net/http/pprof"
"os"
"time"
pprof_runtime "runtime/pprof"
"github.com/golang/glog"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/prometheus/web/api"
"github.com/prometheus/prometheus/web/blob"
)
// Commandline flags.
var (
listenAddress = flag.String("listenAddress", ":9090", "Address to listen on for web interface.")
useLocalAssets = flag.Bool("useLocalAssets", false, "Read assets/templates from file instead of binary.")
userAssetsPath = flag.String("userAssets", "", "Path to static asset directory, available at /user")
enableQuit = flag.Bool("web.enableRemoteShutdown", false, "Enable remote service shutdown")
)
type WebService struct {
StatusHandler *PrometheusStatusHandler
DatabasesHandler *DatabasesHandler
MetricsHandler *api.MetricsService
AlertsHandler *AlertsHandler
ConsolesHandler *ConsolesHandler
QuitDelegate func()
}
func (w WebService) ServeForever() error {
http.Handle("/favicon.ico", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
http.Error(w, "", 404)
}))
http.Handle("/", prometheus.InstrumentHandler(
"/", w.StatusHandler,
))
http.Handle("/databases", prometheus.InstrumentHandler(
"/databases", w.DatabasesHandler,
))
http.Handle("/alerts", prometheus.InstrumentHandler(
"/alerts", w.AlertsHandler,
))
http.Handle("/consoles/", prometheus.InstrumentHandler(
"/consoles/", http.StripPrefix("/consoles/", w.ConsolesHandler),
))
http.Handle("/graph", prometheus.InstrumentHandler(
"/graph", http.HandlerFunc(graphHandler),
))
http.Handle("/heap", prometheus.InstrumentHandler(
"/heap", http.HandlerFunc(dumpHeap),
))
w.MetricsHandler.RegisterHandler()
http.Handle("/metrics", prometheus.Handler())
if *useLocalAssets {
http.Handle("/static/", prometheus.InstrumentHandler(
"/static/", http.StripPrefix("/static/", http.FileServer(http.Dir("web/static"))),
))
} else {
http.Handle("/static/", prometheus.InstrumentHandler(
"/static/", http.StripPrefix("/static/", new(blob.Handler)),
))
}
if *userAssetsPath != "" {
http.Handle("/user/", prometheus.InstrumentHandler(
"/user/", http.StripPrefix("/user/", http.FileServer(http.Dir(*userAssetsPath))),
))
}
if *enableQuit {
http.Handle("/-/quit", http.HandlerFunc(w.quitHandler))
}
glog.Info("listening on ", *listenAddress)
return http.ListenAndServe(*listenAddress, nil)
}
func (s WebService) quitHandler(w http.ResponseWriter, r *http.Request) {
if r.Method != "POST" {
w.Header().Add("Allow", "POST")
w.WriteHeader(http.StatusMethodNotAllowed)
return
}
fmt.Fprintf(w, "Requesting termination... Goodbye!")
s.QuitDelegate()
}
func getTemplateFile(name string) (string, error) {
if *useLocalAssets {
file, err := ioutil.ReadFile(fmt.Sprintf("web/templates/%s.html", name))
if err != nil {
glog.Errorf("Could not read %s template: %s", name, err)
return "", err
}
return string(file), nil
} else {
file, err := blob.GetFile(blob.TemplateFiles, name+".html")
if err != nil {
glog.Errorf("Could not read %s template: %s", name, err)
return "", err
}
return string(file), nil
}
}
func getTemplate(name string) (t *template.Template, err error) {
t = template.New("_base")
t.Funcs(template.FuncMap{
"since": time.Since,
})
file, err := getTemplateFile("_base")
if err != nil {
glog.Error("Could not read base template: ", err)
return nil, err
}
t.Parse(file)
file, err = getTemplateFile(name)
if err != nil {
glog.Error("Could not read base template: ", err)
return nil, err
}
t.Parse(file)
return
}
func executeTemplate(w http.ResponseWriter, name string, data interface{}) {
tpl, err := getTemplate(name)
if err != nil {
glog.Error("Error preparing layout template: ", err)
return
}
err = tpl.Execute(w, data)
if err != nil {
glog.Error("Error executing template: ", err)
}
}
func dumpHeap(w http.ResponseWriter, r *http.Request) {
target := fmt.Sprintf("/tmp/%d.heap", time.Now().Unix())
f, err := os.Create(target)
if err != nil {
glog.Error("Could not dump heap: ", err)
}
fmt.Fprintf(w, "Writing to %s...", target)
defer f.Close()
pprof_runtime.WriteHeapProfile(f)
fmt.Fprintf(w, "Done")
}
func MustBuildServerUrl() string {
_, port, err := net.SplitHostPort(*listenAddress)
if err != nil {
panic(err)
}
hostname, err := os.Hostname()
if err != nil {
panic(err)
}
return fmt.Sprintf("http://%s:%s", hostname, port)
}