/
socket.go
139 lines (117 loc) · 3.52 KB
/
socket.go
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// Copyright 2016 Canonical Ltd.
// Licensed under the AGPLv3, see LICENCE file for details.
package introspection
import (
"fmt"
"net"
"net/http"
"runtime"
"github.com/juju/errors"
"github.com/juju/loggo"
"gopkg.in/tomb.v1"
"gopkg.in/yaml.v2"
"github.com/juju/juju/worker"
"github.com/juju/juju/worker/introspection/pprof"
)
var logger = loggo.GetLogger("juju.worker.introspection")
// DepEngineReporter provides insight into the running dependency engine of the agent.
type DepEngineReporter interface {
// Report returns a map describing the state of the receiver. It is expected
// to be goroutine-safe.
Report() map[string]interface{}
}
// Config describes the arguments required to create the introspection worker.
type Config struct {
SocketName string
Reporter DepEngineReporter
}
// Validate checks the config values to assert they are valid to create the worker.
func (c *Config) Validate() error {
if c.SocketName == "" {
return errors.NotValidf("empty SocketName")
}
return nil
}
// socketListener is a worker and constructed with NewWorker.
type socketListener struct {
tomb tomb.Tomb
listener *net.UnixListener
reporter DepEngineReporter
done chan struct{}
}
// NewWorker starts an http server listening on an abstract domain socket
// which will be created with the specified name.
func NewWorker(config Config) (worker.Worker, error) {
if err := config.Validate(); err != nil {
return nil, errors.Trace(err)
}
if runtime.GOOS != "linux" {
return nil, errors.NotSupportedf("os %q", runtime.GOOS)
}
path := "@" + config.SocketName
addr, err := net.ResolveUnixAddr("unix", path)
if err != nil {
return nil, errors.Annotate(err, "unable to resolve unix socket")
}
l, err := net.ListenUnix("unix", addr)
if err != nil {
return nil, errors.Annotate(err, "unable to listen on unix socket")
}
logger.Debugf("introspection worker listening on %q", path)
w := &socketListener{
listener: l,
reporter: config.Reporter,
done: make(chan struct{}),
}
go w.serve()
go w.run()
return w, nil
}
func (w *socketListener) serve() {
mux := http.NewServeMux()
mux.Handle("/debug/pprof/", http.HandlerFunc(pprof.Index))
mux.Handle("/debug/pprof/cmdline", http.HandlerFunc(pprof.Cmdline))
mux.Handle("/debug/pprof/profile", http.HandlerFunc(pprof.Profile))
mux.Handle("/debug/pprof/symbol", http.HandlerFunc(pprof.Symbol))
mux.Handle("/depengine/", http.HandlerFunc(w.depengineReport))
srv := http.Server{
Handler: mux,
}
logger.Debugf("stats worker now servering")
defer logger.Debugf("stats worker servering finished")
defer close(w.done)
srv.Serve(w.listener)
}
func (w *socketListener) run() {
defer w.tomb.Done()
defer logger.Debugf("stats worker finished")
<-w.tomb.Dying()
logger.Debugf("stats worker closing listener")
w.listener.Close()
// Don't mark the worker as done until the serve goroutine has finished.
<-w.done
}
// Kill implements worker.Worker.
func (w *socketListener) Kill() {
w.tomb.Kill(nil)
}
// Wait implements worker.Worker.
func (w *socketListener) Wait() error {
return w.tomb.Wait()
}
func (s *socketListener) depengineReport(w http.ResponseWriter, r *http.Request) {
if s.reporter == nil {
w.WriteHeader(http.StatusNotFound)
fmt.Fprintln(w, "missing reporter")
return
}
bytes, err := yaml.Marshal(s.reporter.Report())
if err != nil {
w.WriteHeader(http.StatusInternalServerError)
fmt.Fprintf(w, "error: %v\n", err)
return
}
w.Header().Set("Content-Type", "text/plain; charset=utf-8")
fmt.Fprint(w, "Dependency Engine Report\n\n")
w.Write(bytes)
}