feat: idle sleep for proxmox LXCs

internal/idlewatcher/handle_http.go

@@ -0,0 +1,132 @@
+package idlewatcher
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"strconv"
+	"time"
+
+	"github.com/yusing/go-proxy/internal/api/v1/favicon"
+	gphttp "github.com/yusing/go-proxy/internal/net/gphttp"
+	"github.com/yusing/go-proxy/internal/net/gphttp/httpheaders"
+)
+
+type ForceCacheControl struct {
+	expires string
+	http.ResponseWriter
+}
+
+func (f *ForceCacheControl) WriteHeader(code int) {
+	f.ResponseWriter.Header().Set("Cache-Control", "must-revalidate")
+	f.ResponseWriter.Header().Set("Expires", f.expires)
+	f.ResponseWriter.WriteHeader(code)
+}
+
+func (f *ForceCacheControl) Unwrap() http.ResponseWriter {
+	return f.ResponseWriter
+}
+
+// ServeHTTP implements http.Handler.
+func (w *Watcher) ServeHTTP(rw http.ResponseWriter, r *http.Request) {
+	shouldNext := w.wakeFromHTTP(rw, r)
+	if !shouldNext {
+		return
+	}
+	select {
+	case <-r.Context().Done():
+		return
+	default:
+		f := &ForceCacheControl{expires: w.expires().Format(http.TimeFormat), ResponseWriter: rw}
+		w.rp.ServeHTTP(f, r)
+	}
+}
+
+func isFaviconPath(path string) bool {
+	return path == "/favicon.ico"
+}
+
+func (w *Watcher) wakeFromHTTP(rw http.ResponseWriter, r *http.Request) (shouldNext bool) {
+	w.resetIdleTimer()
+
+	// pass through if container is already ready
+	if w.ready() {
+		return true
+	}
+
+	// handle favicon request
+	if isFaviconPath(r.URL.Path) {
+		r.URL.RawQuery = "alias=" + w.rp.TargetName
+		favicon.GetFavIcon(rw, r)
+		return false
+	}
+
+	// Check if start endpoint is configured and request path matches
+	if w.cfg.StartEndpoint != "" && r.URL.Path != w.cfg.StartEndpoint {
+		http.Error(rw, "Forbidden: Container can only be started via configured start endpoint", http.StatusForbidden)
+		return false
+	}
+
+	accept := gphttp.GetAccept(r.Header)
+	acceptHTML := (r.Method == http.MethodGet && accept.AcceptHTML() || r.RequestURI == "/" && accept.IsEmpty())
+
+	isCheckRedirect := r.Header.Get(httpheaders.HeaderGoDoxyCheckRedirect) != ""
+	if !isCheckRedirect && acceptHTML {
+		// Send a loading response to the client
+		body := w.makeLoadingPageBody()
+		rw.Header().Set("Content-Type", "text/html; charset=utf-8")
+		rw.Header().Set("Content-Length", strconv.Itoa(len(body)))
+		rw.Header().Set("Cache-Control", "no-cache")
+		rw.Header().Add("Cache-Control", "no-store")
+		rw.Header().Add("Cache-Control", "must-revalidate")
+		rw.Header().Add("Connection", "close")
+		if _, err := rw.Write(body); err != nil {
+			return false
+		}
+		return false
+	}
+
+	ctx, cancel := context.WithTimeoutCause(r.Context(), w.cfg.WakeTimeout, errors.New("wake timeout"))
+	defer cancel()
+
+	if w.cancelled(ctx) {
+		gphttp.ServerError(rw, r, context.Cause(ctx), http.StatusServiceUnavailable)
+		return false
+	}
+
+	w.l.Trace().Msg("signal received")
+	err := w.wakeIfStopped()
+	if err != nil {
+		gphttp.ServerError(rw, r, err)
+		return false
+	}
+
+	var ready bool
+
+	for {
+		w.resetIdleTimer()
+
+		if w.cancelled(ctx) {
+			gphttp.ServerError(rw, r, context.Cause(ctx), http.StatusServiceUnavailable)
+			return false
+		}
+
+		w, ready, err = checkUpdateState(w.Key())
+		if err != nil {
+			gphttp.ServerError(rw, r, err)
+			return false
+		}
+		if ready {
+			if isCheckRedirect {
+				w.l.Debug().Stringer("url", w.hc.URL()).Msg("container is ready, redirecting")
+				rw.WriteHeader(http.StatusOK)
+				return false
+			}
+			w.l.Debug().Stringer("url", w.hc.URL()).Msg("container is ready, passing through")
+			return true
+		}
+
+		// retry until the container is ready or timeout
+		time.Sleep(idleWakerCheckInterval)
+	}
+}