TUN-1893: Proxy requests to the origin based on tunnel hostname

tunnelhostnamemapper/tunnelhostnamemapper.go

@@ -0,0 +1,49 @@
+package tunnelhostnamemapper
+
+import (
+	"sync"
+
+	"github.com/cloudflare/cloudflared/h2mux"
+	"github.com/cloudflare/cloudflared/originservice"
+)
+
+// TunnelHostnameMapper maps TunnelHostname to an OriginService
+type TunnelHostnameMapper struct {
+	sync.RWMutex
+	tunnelHostnameToOrigin map[h2mux.TunnelHostname]originservice.OriginService
+}
+
+func NewTunnelHostnameMapper() *TunnelHostnameMapper {
+	return &TunnelHostnameMapper{
+		tunnelHostnameToOrigin: make(map[h2mux.TunnelHostname]originservice.OriginService),
+	}
+}
+
+// Get an OriginService given a TunnelHostname
+func (om *TunnelHostnameMapper) Get(key h2mux.TunnelHostname) (originservice.OriginService, bool) {
+	om.RLock()
+	defer om.RUnlock()
+	originService, ok := om.tunnelHostnameToOrigin[key]
+	return originService, ok
+}
+
+// Add a mapping. If there is already an OriginService with this key, shutdown the old origin service and replace it
+// with the new one
+func (om *TunnelHostnameMapper) Add(key h2mux.TunnelHostname, os originservice.OriginService) {
+	om.Lock()
+	defer om.Unlock()
+	if oldOS, ok := om.tunnelHostnameToOrigin[key]; ok {
+		oldOS.Shutdown()
+	}
+	om.tunnelHostnameToOrigin[key] = os
+}
+
+// DeleteAll mappings, and shutdown all OriginService
+func (om *TunnelHostnameMapper) DeleteAll() {
+	om.Lock()
+	defer om.Unlock()
+	for key, os := range om.tunnelHostnameToOrigin {
+		os.Shutdown()
+		delete(om.tunnelHostnameToOrigin, key)
+	}
+}

tunnelhostnamemapper/tunnelhostnamemapper_test.go

@@ -0,0 +1,69 @@
+package tunnelhostnamemapper
+
+import (
+	"fmt"
+	"net/http"
+	"sync"
+	"testing"
+
+	"github.com/cloudflare/cloudflared/h2mux"
+	"github.com/cloudflare/cloudflared/originservice"
+	"github.com/stretchr/testify/assert"
+)
+
+const (
+	routines = 1000
+)
+
+func TestTunnelHostnameMapperConcurrentAccess(t *testing.T) {
+	thm := NewTunnelHostnameMapper()
+
+	concurrentOps(t, func(i int) {
+		// om is empty
+		os, ok := thm.Get(tunnelHostname(i))
+		assert.False(t, ok)
+		assert.Nil(t, os)
+	})
+
+	httpOS := originservice.NewHTTPService(http.DefaultTransport, "127.0.0.1:8080", false)
+	concurrentOps(t, func(i int) {
+		thm.Add(tunnelHostname(i), httpOS)
+	})
+
+	concurrentOps(t, func(i int) {
+		os, ok := thm.Get(tunnelHostname(i))
+		assert.True(t, ok)
+		assert.Equal(t, httpOS, os)
+	})
+
+	secondHTTPOS := originservice.NewHTTPService(http.DefaultTransport, "127.0.0.1:8090", true)
+	concurrentOps(t, func(i int) {
+		// Add should httpOS with secondHTTPOS
+		thm.Add(tunnelHostname(i), secondHTTPOS)
+	})
+
+	concurrentOps(t, func(i int) {
+		os, ok := thm.Get(tunnelHostname(i))
+		assert.True(t, ok)
+		assert.Equal(t, secondHTTPOS, os)
+	})
+
+	thm.DeleteAll()
+	assert.Empty(t, thm.tunnelHostnameToOrigin)
+}
+
+func concurrentOps(t *testing.T, f func(i int)) {
+	var wg sync.WaitGroup
+	wg.Add(routines)
+	for i := 0; i < routines; i++ {
+		go func(i int) {
+			f(i)
+			wg.Done()
+		}(i)
+	}
+	wg.Wait()
+}
+
+func tunnelHostname(i int) h2mux.TunnelHostname {
+	return h2mux.TunnelHostname(fmt.Sprintf("%d.cftunnel.com", i))
+}