refactored http import name, fixed and simplified idlewatcher/idlewaker implementation, dependencies update

internal/docker/idlewatcher/waker.go

@@ -0,0 +1,101 @@
+package idlewatcher
+
+import (
+	"context"
+	"crypto/tls"
+	"net/http"
+	"time"
+
+	gphttp "github.com/yusing/go-proxy/internal/net/http"
+)
+
+type Waker struct {
+	*watcher
+
+	client *http.Client
+	rp     *gphttp.ReverseProxy
+}
+
+func NewWaker(w *watcher, rp *gphttp.ReverseProxy) *Waker {
+	tr := &http.Transport{}
+	if w.NoTLSVerify {
+		tr.TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
+	}
+	return &Waker{
+		watcher: w,
+		client: &http.Client{
+			Timeout:   1 * time.Second,
+			Transport: tr,
+		},
+		rp: rp,
+	}
+}
+
+func (w *Waker) ServeHTTP(rw http.ResponseWriter, r *http.Request) {
+	w.wake(w.rp.ServeHTTP, rw, r)
+}
+
+func (w *Waker) wake(next http.HandlerFunc, rw http.ResponseWriter, r *http.Request) {
+	// pass through if container is ready
+	if w.ready.Load() {
+		next(rw, r)
+		return
+	}
+
+	ctx, cancel := context.WithTimeout(r.Context(), w.WakeTimeout)
+	defer cancel()
+
+	if r.Header.Get(headerCheckRedirect) == "" {
+		// Send a loading response to the client
+		rw.Header().Set("Content-Type", "text/html; charset=utf-8")
+		rw.Write(w.makeRespBody("%s waking up...", w.ContainerName))
+		return
+	}
+
+	// wake the container and reset idle timer
+	// also wait for another wake request
+	w.wakeCh <- struct{}{}
+
+	if <-w.wakeDone != nil {
+		http.Error(rw, "Error sending wake request", http.StatusInternalServerError)
+		return
+	}
+
+	// maybe another request came in while we were waiting for the wake
+	if w.ready.Load() {
+		next(rw, r)
+		return
+	}
+
+	for {
+		select {
+		case <-ctx.Done():
+			http.Error(rw, "Waking timed out", http.StatusGatewayTimeout)
+			return
+		default:
+		}
+
+		wakeReq, err := http.NewRequestWithContext(
+			ctx,
+			http.MethodHead,
+			w.URL.String(),
+			nil,
+		)
+		if err != nil {
+			w.l.Errorf("new request err to %s: %s", r.URL, err)
+			http.Error(rw, "Internal server error", http.StatusInternalServerError)
+			return
+		}
+
+		// we don't care about the response
+		_, err = w.client.Do(wakeReq)
+		if err == nil {
+			w.ready.Store(true)
+			rw.WriteHeader(http.StatusOK)
+			return
+		}
+
+		// retry until the container is ready or timeout
+		time.Sleep(100 * time.Millisecond)
+	}
+}