improved idlewatcher support for API-like services, fixed idlewaker proxying to zero port

internal/docker/idlewatcher/waker.go

@@ -3,6 +3,7 @@ package idlewatcher
 import (
 	"context"
 	"crypto/tls"
+	"fmt"
 	"net/http"
 	"strconv"
 	"time"
@@ -22,6 +23,20 @@ func NewWaker(w *watcher, rp *gphttp.ReverseProxy) *Waker {
 	if w.NoTLSVerify {
 		tr.TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
 	}
+	orig := rp.ServeHTTP
+	// workaround for stopped containers port become zero
+	rp.ServeHTTP = func(rw http.ResponseWriter, r *http.Request) {
+		if rp.TargetURL.Port() == "0" {
+			port, ok := portHistoryMap.Load(w.Alias)
+			if !ok {
+				w.l.Errorf("port history not found for %s", w.Alias)
+				http.Error(rw, "internal server error", http.StatusInternalServerError)
+				return
+			}
+			rp.TargetURL.Host = fmt.Sprintf("%s:%v", rp.TargetURL.Hostname(), port)
+		}
+		orig(rw, r)
+	}
 	return &Waker{
 		watcher: w,
 		client: &http.Client{
@@ -37,9 +52,10 @@ func (w *Waker) ServeHTTP(rw http.ResponseWriter, r *http.Request) {
 }
 
 func (w *Waker) wake(next http.HandlerFunc, rw http.ResponseWriter, r *http.Request) {
+	w.resetIdleTimer()
+
 	// pass through if container is ready
 	if w.ready.Load() {
-		w.resetIdleTimer()
 		next(rw, r)
 		return
 	}
@@ -48,14 +64,10 @@ func (w *Waker) wake(next http.HandlerFunc, rw http.ResponseWriter, r *http.Requ
 	defer cancel()
 
 	accept := gphttp.GetAccept(r.Header)
-	acceptHTML := accept.AcceptHTML() || accept.IsEmpty()
+	acceptHTML := r.Method == http.MethodGet && accept.AcceptHTML()
 
-	if !acceptHTML {
-		w.l.Debugf("Accept %v", accept)
-	}
-
-	isCheckRedirect := r.Header.Get(headerCheckRedirect) != "" && acceptHTML
-	if !isCheckRedirect {
+	isCheckRedirect := r.Header.Get(headerCheckRedirect) != ""
+	if !isCheckRedirect && acceptHTML {
 		// Send a loading response to the client
 		body := w.makeRespBody("%s waking up...", w.ContainerName)
 		rw.Header().Set("Content-Type", "text/html; charset=utf-8")
@@ -106,10 +118,10 @@ func (w *Waker) wake(next http.HandlerFunc, rw http.ResponseWriter, r *http.Requ
 			return
 		}
 
-		// we don't care about the response
-		_, err = w.client.Do(wakeReq)
-		if err == nil {
+		wakeResp, err := w.client.Do(wakeReq)
+		if err == nil && wakeResp.StatusCode != http.StatusServiceUnavailable {
 			w.ready.Store(true)
+			w.l.Debug("awaken")
 			if isCheckRedirect {
 				rw.WriteHeader(http.StatusOK)
 			} else {

internal/docker/idlewatcher/watcher.go

@@ -12,6 +12,7 @@ import (
 	E "github.com/yusing/go-proxy/internal/error"
 	P "github.com/yusing/go-proxy/internal/proxy"
 	PT "github.com/yusing/go-proxy/internal/proxy/fields"
+	F "github.com/yusing/go-proxy/internal/utils/functional"
 	W "github.com/yusing/go-proxy/internal/watcher"
 )
 
@@ -45,9 +46,11 @@ var (
 	mainLoopCancel context.CancelFunc
 	mainLoopWg     sync.WaitGroup
 
-	watcherMap   = make(map[string]*watcher)
+	watcherMap   = F.NewMapOf[string, *watcher]()
 	watcherMapMu sync.Mutex
 
+	portHistoryMap = F.NewMapOf[PT.Alias, string]()
+
 	newWatcherCh = make(chan *watcher)
 
 	logger = logrus.WithField("module", "idle_watcher")
@@ -65,7 +68,11 @@ func Register(entry *P.ReverseProxyEntry) (*watcher, E.NestedError) {
 
 	key := entry.ContainerID
 
-	if w, ok := watcherMap[key]; ok {
+	if entry.URL.Port() != "0" {
+		portHistoryMap.Store(entry.Alias, entry.URL.Port())
+	}
+
+	if w, ok := watcherMap.Load(key); ok {
 		w.refCount.Add(1)
 		w.ReverseProxyEntry = entry
 		return w, nil
@@ -88,7 +95,7 @@ func Register(entry *P.ReverseProxyEntry) (*watcher, E.NestedError) {
 	w.refCount.Add(1)
 	w.stopByMethod = w.getStopCallback()
 
-	watcherMap[key] = w
+	watcherMap.Store(key, w)
 
 	go func() {
 		newWatcherCh <- w
@@ -118,7 +125,7 @@ func Start() {
 				w.watchUntilCancel()
 				w.refCount.Wait() // wait for 0 ref count
 
-				delete(watcherMap, w.ContainerID)
+				watcherMap.Delete(w.ContainerID)
 				w.l.Debug("unregistered")
 				mainLoopWg.Done()
 			}()

internal/net/http/reverse_proxy_mod.go

@@ -69,36 +69,6 @@ type ProxyRequest struct {
 // 1xx responses are forwarded to the client if the underlying
 // transport supports ClientTrace.Got1xxResponse.
 type ReverseProxy struct {
-	// Director is a function which modifies
-	// the request into a new request to be sent
-	// using Transport. Its response is then copied
-	// back to the original client unmodified.
-	// Director must not access the provided Request
-	// after returning.
-	//
-	// By default, the X-Forwarded-For header is set to the
-	// value of the client IP address. If an X-Forwarded-For
-	// header already exists, the client IP is appended to the
-	// existing values. As a special case, if the header
-	// exists in the Request.Header map but has a nil value
-	// (such as when set by the Director func), the X-Forwarded-For
-	// header is not modified.
-	//
-	// To prevent IP spoofing, be sure to delete any pre-existing
-	// X-Forwarded-For header coming from the client or
-	// an untrusted proxy.
-	//
-	// Hop-by-hop headers are removed from the request after
-	// Director returns, which can remove headers added by
-	// Director. Use a Rewrite function instead to ensure
-	// modifications to the request are preserved.
-	//
-	// Unparsable query parameters are removed from the outbound
-	// request if Request.Form is set after Director returns.
-	//
-	// At most one of Rewrite or Director may be set.
-	Director func(*http.Request)
-
 	// The transport used to perform proxy requests.
 	// If nil, http.DefaultTransport is used.
 	Transport http.RoundTripper
@@ -115,6 +85,8 @@ type ReverseProxy struct {
 	ModifyResponse func(*http.Response) error
 
 	ServeHTTP http.HandlerFunc
+
+	TargetURL *url.URL
 }
 
 func singleJoiningSlash(a, b string) string {
@@ -176,12 +148,7 @@ func NewReverseProxy(target *url.URL, transport http.RoundTripper) *ReverseProxy
 	if transport == nil {
 		panic("nil transport")
 	}
-	rp := &ReverseProxy{
-		Director: func(req *http.Request) {
-			rewriteRequestURL(req, target)
-		},
-		Transport: transport,
-	}
+	rp := &ReverseProxy{Transport: transport, TargetURL: target}
 	rp.ServeHTTP = rp.serveHTTP
 	return rp
 }
@@ -296,7 +263,7 @@ func (p *ReverseProxy) serveHTTP(rw http.ResponseWriter, req *http.Request) {
 		outreq.Header = make(http.Header) // Issue 33142: historical behavior was to always allocate
 	}
 
-	p.Director(outreq)
+	rewriteRequestURL(outreq, p.TargetURL)
 	outreq.Close = false
 
 	reqUpType := UpgradeType(outreq.Header)