v0.5-rc2: added reload cooldown, fixed auto reload, updated API

src/proxy/provider/provider.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"path"
+	"time"
 
 	"github.com/sirupsen/logrus"
 	E "github.com/yusing/go-proxy/error"
@@ -30,6 +31,8 @@ type Provider struct {
 	watcherCancel context.CancelFunc
 
 	l *logrus.Entry
+
+	cooldownCh chan struct{}
 }
 
 type ProviderType string
@@ -45,9 +48,10 @@ func newProvider(name string, t ProviderType) *Provider {
 		t:           t,
 		routes:      R.NewRoutes(),
 		reloadReqCh: make(chan struct{}, 1),
+		cooldownCh:  make(chan struct{}, 1),
 	}
 	p.l = logrus.WithField("provider", p)
-
+	go p.processReloadRequests()
 	return p
 }
 func NewFileProvider(filename string) *Provider {
@@ -100,7 +104,8 @@ func (p *Provider) StartAllRoutes() E.NestedError {
 			nStarted++
 		}
 	})
-	p.l.Infof("%d routes started, %d failed", nStarted, nFailed)
+
+	p.l.Debugf("%d routes started, %d failed", nStarted, nFailed)
 	return errors.Build()
 }
 
@@ -120,16 +125,17 @@ func (p *Provider) StopAllRoutes() E.NestedError {
 			nStopped++
 		}
 	})
-	p.l.Infof("%d routes stopped, %d failed", nStopped, nFailed)
+	p.l.Debugf("%d routes stopped, %d failed", nStopped, nFailed)
 	return errors.Build()
 }
 
 func (p *Provider) ReloadRoutes() {
-	defer p.l.Info("routes reloaded")
-
-	p.StopAllRoutes()
-	p.loadRoutes()
-	p.StartAllRoutes()
+	select {
+	case p.reloadReqCh <- struct{}{}:
+		// Successfully sent reload request
+	default:
+		// Reload request already in progress, ignore this request
+	}
 }
 
 func (p *Provider) GetCurrentRoutes() *R.Routes {
@@ -142,15 +148,14 @@ func (p *Provider) watchEvents() {
 
 	for {
 		select {
-		case <-p.reloadReqCh: // block until last reload is done
-			p.ReloadRoutes()
-			continue // ignore events once after reload
+		case <-p.watcherCtx.Done():
+			return
 		case event, ok := <-events:
 			if !ok {
 				return
 			}
 			l.Info(event)
-			p.reloadReqCh <- struct{}{}
+			p.ReloadRoutes()
 		case err, ok := <-errs:
 			if !ok {
 				return
@@ -163,6 +168,29 @@ func (p *Provider) watchEvents() {
 	}
 }
 
+func (p *Provider) processReloadRequests() {
+	for range p.reloadReqCh {
+		// prevent busy loop caused by a container
+		// repeating crashing and restarting
+		select {
+		case p.cooldownCh <- struct{}{}:
+			p.l.Info("Starting to reload routes")
+
+			p.StopAllRoutes()
+			p.loadRoutes()
+			p.StartAllRoutes()
+
+			p.l.Info("Routes reloaded")
+
+			go func() {
+				time.Sleep(reloadCooldown)
+				<-p.cooldownCh
+			}()
+		default:
+		}
+	}
+}
+
 func (p *Provider) loadRoutes() E.NestedError {
 	entries, err := p.GetProxyEntries()
 
@@ -183,3 +211,5 @@ func (p *Provider) loadRoutes() E.NestedError {
 	})
 	return errors.Build()
 }
+
+const reloadCooldown = 300 * time.Millisecond

src/route/http_route.go

@@ -19,10 +19,9 @@ import (
 
 type (
 	HTTPRoute struct {
-		Alias PT.Alias `json:"alias"`
-
-		TargetURL    URL
-		PathPatterns PT.PathPatterns
+		Alias        PT.Alias        `json:"alias"`
+		TargetURL    *URL            `json:"target_url"`
+		PathPatterns PT.PathPatterns `json:"path_patterns"`
 
 		mux     *http.ServeMux
 		handler *P.ReverseProxy
@@ -53,7 +52,7 @@ func NewHTTPRoute(entry *P.Entry) (*HTTPRoute, E.NestedError) {
 	if !ok {
 		r = &HTTPRoute{
 			Alias:        entry.Alias,
-			TargetURL:    URL(*entry.URL),
+			TargetURL:    (*URL)(entry.URL),
 			PathPatterns: entry.PathPatterns,
 			handler:      rp,
 		}

src/watcher/file_watcher.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"path"
 
+	"github.com/yusing/go-proxy/common"
 	E "github.com/yusing/go-proxy/error"
 )
 
@@ -22,4 +23,4 @@ func (f *fileWatcher) Events(ctx context.Context) (<-chan Event, <-chan E.Nested
 	return fwHelper.Add(ctx, f)
 }
 
-var fwHelper = newFileWatcherHelper()
+var fwHelper = newFileWatcherHelper(common.ConfigBasePath)

src/watcher/file_watcher_helper.go

@@ -8,7 +8,6 @@ import (
 
 	"github.com/fsnotify/fsnotify"
 	"github.com/sirupsen/logrus"
-	"github.com/yusing/go-proxy/common"
 	E "github.com/yusing/go-proxy/error"
 )
 
@@ -26,14 +25,12 @@ type fileWatcherStream struct {
 	errCh   chan E.NestedError
 }
 
-func newFileWatcherHelper() *fileWatcherHelper {
+func newFileWatcherHelper(dirPath string) *fileWatcherHelper {
 	w, err := fsnotify.NewWatcher()
 	if err != nil {
 		logrus.Panicf("unable to create fs watcher: %s", err)
 	}
-	// watch config path for all changes
-	err = w.Add(common.ConfigBasePath)
-	if err != nil {
+	if err = w.Add(dirPath); err != nil {
 		logrus.Panicf("unable to create fs watcher: %s", err)
 	}
 	helper := &fileWatcherHelper{
@@ -60,26 +57,24 @@ func (h *fileWatcherHelper) Add(ctx context.Context, w *fileWatcher) (<-chan Eve
 		errCh:       make(chan E.NestedError),
 	}
 	go func() {
-		select {
-		case <-ctx.Done():
-			h.Remove(w)
-			return
-		case <-s.stopped:
-			return
+		for {
+			select {
+			case <-ctx.Done():
+				s.stopped <- struct{}{}
+			case <-s.stopped:
+				h.mu.Lock()
+				defer h.mu.Unlock()
+				close(s.eventCh)
+				close(s.errCh)
+				delete(h.m, w.filename)
+				return
+			}
 		}
 	}()
 	h.m[w.filename] = s
 	return s.eventCh, s.errCh
 }
 
-func (h *fileWatcherHelper) Remove(w *fileWatcher) {
-	h.mu.Lock()
-	defer h.mu.Unlock()
-
-	h.m[w.filename].stopped <- struct{}{}
-	delete(h.m, w.filename)
-}
-
 func (h *fileWatcherHelper) start() {
 	defer h.wg.Done()