prometheus/web/web.go

140 lines
4.0 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"
"log"
"net/http"
"net/http/pprof"
"code.google.com/p/gorest"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/exp"
"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")
)
type WebService struct {
StatusHandler *StatusHandler
DatabasesHandler *DatabasesHandler
MetricsHandler *api.MetricsService
AlertsHandler *AlertsHandler
}
func (w WebService) ServeForever() error {
gorest.RegisterService(w.MetricsHandler)
exp.Handle("/favicon.ico", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
http.Error(w, "", 404)
}))
// TODO(julius): This will need to be rewritten once the exp package provides
// the coarse mux behaviors via a wrapper function.
exp.Handle("/debug/pprof/", http.HandlerFunc(pprof.Index))
exp.Handle("/debug/pprof/cmdline", http.HandlerFunc(pprof.Cmdline))
exp.Handle("/debug/pprof/profile", http.HandlerFunc(pprof.Profile))
exp.Handle("/debug/pprof/symbol", http.HandlerFunc(pprof.Symbol))
exp.Handle("/", w.StatusHandler)
exp.Handle("/databases", w.DatabasesHandler)
exp.Handle("/alerts", w.AlertsHandler)
exp.HandleFunc("/graph", graphHandler)
exp.Handle("/api/", compressionHandler{handler: gorest.Handle()})
exp.Handle("/metrics.json", prometheus.DefaultHandler)
if *useLocalAssets {
exp.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir("web/static"))))
} else {
exp.Handle("/static/", http.StripPrefix("/static/", new(blob.Handler)))
}
if *userAssetsPath != "" {
exp.Handle("/user/", http.StripPrefix("/user/", http.FileServer(http.Dir(*userAssetsPath))))
}
log.Printf("listening on %s", *listenAddress)
return http.ListenAndServe(*listenAddress, exp.DefaultCoarseMux)
}
func getLocalTemplate(name string) (*template.Template, error) {
return template.ParseFiles(
"web/templates/_base.html",
fmt.Sprintf("web/templates/%s.html", name),
)
}
func getEmbeddedTemplate(name string) (*template.Template, error) {
t := template.New("_base")
file, err := blob.GetFile(blob.TemplateFiles, "_base.html")
if err != nil {
log.Printf("Could not read base template: %s", err)
return nil, err
}
t.Parse(string(file))
file, err = blob.GetFile(blob.TemplateFiles, name+".html")
if err != nil {
log.Printf("Could not read %s template: %s", name, err)
return nil, err
}
t.Parse(string(file))
return t, nil
}
func getTemplate(name string) (t *template.Template, err error) {
if *useLocalAssets {
t, err = getLocalTemplate(name)
} else {
t, err = getEmbeddedTemplate(name)
}
if err != nil {
return
}
if *userAssetsPath != "" {
// replace "user_dashboard_link" template
t.Parse(`{{define "user_dashboard_link"}}<a href="/user">User Dashboard{{end}}`)
}
return
}
func executeTemplate(w http.ResponseWriter, name string, data interface{}) {
tpl, err := getTemplate(name)
if err != nil {
log.Printf("Error preparing layout template: %s", err)
return
}
err = tpl.Execute(w, data)
if err != nil {
log.Printf("Error executing template: %s", err)
}
}