func watchBackend() {
var (
last string
svccfg string
mancfg string
)
svc := registry.Default.WatchServices()
man := registry.Default.WatchManual()
for {
select {
case svccfg = <-svc:
case mancfg = <-man:
}
// manual config overrides service config
// order matters
next := svccfg + "\n" + mancfg
if next == last {
continue
}
t, err := route.NewTable(next)
if err != nil {
log.Printf("[WARN] %s", err)
continue
}
route.SetTable(t)
last = next
}
}
func mustParseTable(s string) route.Table {
t, err := route.NewTable(s)
if err != nil {
panic(err)
}
return t
}
func TestGracefulShutdown(t *testing.T) {
req := func(url string) int {
resp, err := http.Get(url)
if err != nil {
t.Fatal(err)
}
defer resp.Body.Close()
return resp.StatusCode
}
// start a server which responds after the shutdown has been triggered.
srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
<-quit // wait for shutdown signal
return
}))
defer srv.Close()
// load the routing table
tbl, err := route.NewTable("route add svc / " + srv.URL)
if err != nil {
t.Fatal(err)
}
route.SetTable(tbl)
// start proxy with graceful shutdown period long enough
// to complete one more request.
var wg sync.WaitGroup
l := config.Listen{Addr: "127.0.0.1:57777", Proto: "http"}
wg.Add(1)
go func() {
defer wg.Done()
startListeners([]config.Listen{l}, 250*time.Millisecond, proxy.NewHTTPProxy(http.DefaultTransport, config.Proxy{}), nil)
}()
// trigger shutdown after some time
shutdownDelay := 100 * time.Millisecond
go func() {
time.Sleep(shutdownDelay)
close(quit)
}()
// give proxy some time to start up
// needs to be done before shutdown is triggered
time.Sleep(shutdownDelay / 2)
// make 200 OK request
// start before and complete after shutdown was triggered
if got, want := req("http://"+l.Addr+"/"), 200; got != want {
t.Fatalf("request 1: got %v want %v", got, want)
}
// make 503 request
// start and complete after shutdown was triggered
if got, want := req("http://"+l.Addr+"/"), 503; got != want {
t.Fatalf("got %v want %v", got, want)
}
// wait for listen() to return
// note that the actual listeners have not returned yet
wg.Wait()
}