Files
podinfo/pkg/server/server.go
2018-01-08 17:50:37 +02:00

106 lines
2.3 KiB
Go

package server
import (
"context"
"net/http"
"runtime"
"time"
"github.com/golang/glog"
"github.com/prometheus/client_golang/prometheus/promhttp"
"gopkg.in/yaml.v2"
"sync/atomic"
)
var status int32
type Server struct {
mux *http.ServeMux
}
func New(options ...func(*Server)) *Server {
s := &Server{mux: http.NewServeMux()}
for _, f := range options {
f(s)
}
s.mux.HandleFunc("/", s.index)
s.mux.HandleFunc("/healthz/", s.healthz)
s.mux.HandleFunc("/panic/", s.panic)
s.mux.Handle("/metrics", promhttp.Handler())
return s
}
func (s *Server) index(w http.ResponseWriter, r *http.Request) {
resp, err := makeResponse()
if err != nil {
w.WriteHeader(http.StatusInternalServerError)
w.Write([]byte(err.Error()))
}
d, err := yaml.Marshal(resp)
if err != nil {
w.WriteHeader(http.StatusInternalServerError)
w.Write([]byte(err.Error()))
}
w.Header().Set("Content-Type", "text/x-yaml; charset=utf-8")
w.Header().Set("X-Content-Type-Options", "nosniff")
w.WriteHeader(http.StatusOK)
w.Write(d)
}
func (s *Server) healthz(w http.ResponseWriter, r *http.Request) {
if atomic.LoadInt32(&status) == 1 {
w.WriteHeader(http.StatusOK)
w.Write([]byte("OK"))
return
}
w.WriteHeader(http.StatusServiceUnavailable)
}
func (s *Server) panic(w http.ResponseWriter, r *http.Request) {
glog.Fatal("Kill switch triggered")
}
func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Server", runtime.Version())
s.mux.ServeHTTP(w, r)
}
func ListenAndServe(port string, timeout time.Duration, stopCh <-chan struct{}) {
srv := &http.Server{
Addr: ":" + port,
Handler: New(),
ReadTimeout: 5 * time.Second,
WriteTimeout: 10 * time.Second,
IdleTimeout: 15 * time.Second,
}
atomic.StoreInt32(&status, 1)
// run server in background
go func() {
if err := srv.ListenAndServe(); err != http.ErrServerClosed {
glog.Fatal(err)
}
}()
// wait for SIGTERM or SIGINT
<-stopCh
atomic.StoreInt32(&status, 0)
ctx, cancel := context.WithTimeout(context.Background(), timeout)
defer cancel()
glog.Infof("Shutting down HTTP server with timeout: %v", timeout)
if err := srv.Shutdown(ctx); err != nil {
glog.Errorf("HTTP server graceful shutdown failed with error: %v",err)
} else {
glog.Info("HTTP server stopped")
}
}