95 lines
2.1 KiB
Go
95 lines
2.1 KiB
Go
// Copyright (c) 2015 Arista Networks, Inc.
|
|
// Use of this source code is governed by the Apache License 2.0
|
|
// that can be found in the COPYING file.
|
|
|
|
// Package monitor provides an embedded HTTP server to expose
|
|
// metrics for monitoring
|
|
package monitor
|
|
|
|
import (
|
|
"expvar"
|
|
"fmt"
|
|
"net"
|
|
"net/http"
|
|
_ "net/http/pprof" // Go documentation recommended usage
|
|
|
|
"github.com/aristanetworks/goarista/netns"
|
|
|
|
"github.com/aristanetworks/glog"
|
|
)
|
|
|
|
// Server represents a monitoring server
|
|
type Server interface {
|
|
Run(serveMux *http.ServeMux)
|
|
}
|
|
|
|
// server contains information for the monitoring server
|
|
type server struct {
|
|
vrfName string
|
|
// Server name e.g. host[:port]
|
|
serverName string
|
|
}
|
|
|
|
// NewServer creates a new server struct
|
|
func NewServer(address string) Server {
|
|
vrfName, addr, err := netns.ParseAddress(address)
|
|
if err != nil {
|
|
glog.Errorf("Failed to parse address: %s", err)
|
|
}
|
|
return &server{
|
|
vrfName: vrfName,
|
|
serverName: addr,
|
|
}
|
|
}
|
|
|
|
func debugHandler(w http.ResponseWriter, r *http.Request) {
|
|
indexTmpl := `<html>
|
|
<head>
|
|
<title>/debug</title>
|
|
</head>
|
|
<body>
|
|
<p>/debug</p>
|
|
<div><a href="/debug/vars">vars</a></div>
|
|
<div><a href="/debug/pprof">pprof</a></div>
|
|
</body>
|
|
</html>
|
|
`
|
|
fmt.Fprintf(w, indexTmpl)
|
|
}
|
|
|
|
// PrintableHistogram represents a Histogram that can be printed as
|
|
// a chart.
|
|
type PrintableHistogram interface {
|
|
Print() string
|
|
}
|
|
|
|
// Pretty prints the latency histograms
|
|
func histogramHandler(w http.ResponseWriter, r *http.Request) {
|
|
expvar.Do(func(kv expvar.KeyValue) {
|
|
if hist, ok := kv.Value.(PrintableHistogram); ok {
|
|
w.Write([]byte(hist.Print()))
|
|
}
|
|
})
|
|
}
|
|
|
|
// Run sets up the HTTP server and any handlers
|
|
func (s *server) Run(serveMux *http.ServeMux) {
|
|
serveMux.HandleFunc("/debug", debugHandler)
|
|
serveMux.HandleFunc("/debug/histograms", histogramHandler)
|
|
|
|
var listener net.Listener
|
|
err := netns.Do(s.vrfName, func() error {
|
|
var err error
|
|
listener, err = net.Listen("tcp", s.serverName)
|
|
return err
|
|
})
|
|
if err != nil {
|
|
glog.Fatalf("Could not start monitor server in VRF %q: %s", s.vrfName, err)
|
|
}
|
|
|
|
err = http.Serve(listener, serveMux)
|
|
if err != nil {
|
|
glog.Fatal("http serve returned with error:", err)
|
|
}
|
|
}
|