Improve server startup/shutdown

Closes #9671

commands/server.go

@@ -15,6 +15,7 @@ package commands
 
 import (
 	"bytes"
+	"context"
 	"fmt"
 	"io"
 	"net"
@@ -32,6 +33,7 @@ import (
 	"time"
 
 	"github.com/gohugoio/hugo/common/paths"
+	"golang.org/x/sync/errgroup"
 
 	"github.com/pkg/errors"
 
@@ -139,7 +141,7 @@ func (sc *serverCmd) server(cmd *cobra.Command, args []string) error {
 
 	var serverCfgInit sync.Once
 
-	cfgInit := func(c *commandeer) error {
+	cfgInit := func(c *commandeer) (rerr error) {
 		c.Set("renderToMemory", !sc.renderToDisk)
 		if cmd.Flags().Changed("navigateToChanged") {
 			c.Set("navigateToChanged", sc.navigateToChanged)
@@ -162,15 +164,13 @@ func (sc *serverCmd) server(cmd *cobra.Command, args []string) error {
 			return nil
 		}
 
-		var err error
-
 		// We can only do this once.
 		serverCfgInit.Do(func() {
 			serverPorts = make([]int, 1)
 
 			if c.languages.IsMultihost() {
 				if !sc.serverAppend {
-					err = newSystemError("--appendPort=false not supported when in multihost mode")
+					rerr = newSystemError("--appendPort=false not supported when in multihost mode")
 				}
 				serverPorts = make([]int, len(c.languages))
 			}
@@ -185,12 +185,14 @@ func (sc *serverCmd) server(cmd *cobra.Command, args []string) error {
 				} else {
 					if i == 0 && sc.cmd.Flags().Changed("port") {
 						// port set explicitly by user -- he/she probably meant it!
-						err = newSystemErrorF("Server startup failed: %s", err)
+						rerr = newSystemErrorF("Server startup failed: %s", err)
+						return
 					}
 					c.logger.Println("port", sc.serverPort, "already in use, attempting to use an available port")
 					sp, err := helpers.FindAvailablePort()
 					if err != nil {
-						err = newSystemError("Unable to find alternative port to use:", err)
+						rerr = newSystemError("Unable to find alternative port to use:", err)
+						return
 					}
 					serverPorts[i] = sp.Port
 				}
@@ -199,6 +201,10 @@ func (sc *serverCmd) server(cmd *cobra.Command, args []string) error {
 			}
 		})
 
+		if rerr != nil {
+			return
+		}
+
 		c.serverPorts = serverPorts
 
 		c.Set("port", sc.serverPort)
@@ -229,7 +235,7 @@ func (sc *serverCmd) server(cmd *cobra.Command, args []string) error {
 			}
 		}
 
-		return err
+		return
 	}
 
 	if err := memStats(); err != nil {
@@ -506,9 +512,15 @@ func (c *commandeer) serve(s *serverCmd) error {
 
 	sigs := make(chan os.Signal, 1)
 	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
+	var servers []*http.Server
 
 	for i := range baseURLs {
 		mu, serverURL, endpoint, err := srv.createEndpoint(i)
+		srv := &http.Server{
+			Addr:    endpoint,
+			Handler: mu,
+		}
+		servers = append(servers, srv)
 
 		if doLiveReload {
 			u, err := url.Parse(helpers.SanitizeURL(baseURLs[i]))
@@ -521,8 +533,8 @@ func (c *commandeer) serve(s *serverCmd) error {
 		}
 		jww.FEEDBACK.Printf("Web Server is available at %s (bind address %s)\n", serverURL, s.serverInterface)
 		go func() {
-			err = http.ListenAndServe(endpoint, mu)
-			if err != nil {
+			err = srv.ListenAndServe()
+			if err != nil && err != http.ErrServerClosed {
 				c.logger.Errorf("Error: %s\n", err.Error())
 				os.Exit(1)
 			}
@@ -542,7 +554,17 @@ func (c *commandeer) serve(s *serverCmd) error {
 
 	c.hugo().Close()
 
-	return nil
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+	wg, ctx := errgroup.WithContext(ctx)
+	for _, srv := range servers {
+		srv := srv
+		wg.Go(func() error {
+			return srv.Shutdown(ctx)
+		})
+	}
+
+	return wg.Wait()
 }
 
 // fixURL massages the baseURL into a form needed for serving

commands/server_test.go

@@ -25,6 +25,8 @@ import (
 
 	"github.com/gohugoio/hugo/config"
 	"github.com/gohugoio/hugo/helpers"
+	"golang.org/x/net/context"
+	"golang.org/x/sync/errgroup"
 
 	qt "github.com/frankban/quicktest"
 )
@@ -107,14 +109,14 @@ func runServerTest(c *qt.C, config string, args ...string) (result serverTestRes
 	defer clean()
 	c.Assert(err, qt.IsNil)
 
-	// Let us hope that this port is available on all systems ...
-	port := 1331
+	sp, err := helpers.FindAvailablePort()
+	c.Assert(err, qt.IsNil)
+	port := sp.Port
 
 	defer func() {
 		os.RemoveAll(dir)
 	}()
 
-	errors := make(chan error)
 	stop := make(chan bool)
 
 	b := newCommandsBuilder()
@@ -124,24 +126,26 @@ func runServerTest(c *qt.C, config string, args ...string) (result serverTestRes
 	args = append([]string{"-s=" + dir, fmt.Sprintf("-p=%d", port)}, args...)
 	cmd.SetArgs(args)
 
-	go func() {
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	wg, ctx := errgroup.WithContext(ctx)
+
+	wg.Go(func() error {
 		_, err := cmd.ExecuteC()
-		if err != nil {
-			errors <- err
-		}
-	}()
+		return err
+	})
 
 	select {
 	// There is no way to know exactly when the server is ready for connections.
 	// We could improve by something like https://golang.org/pkg/net/http/httptest/#Server
 	// But for now, let us sleep and pray!
 	case <-time.After(2 * time.Second):
-	case err := <-errors:
-		result.err = err
+	case <-ctx.Done():
+		result.err = wg.Wait()
 		return
 	}
 
-	resp, err := http.Get("http://localhost:1331/")
+	resp, err := http.Get(fmt.Sprintf("http://localhost:%d/", port))
 	c.Assert(err, qt.IsNil)
 	defer resp.Body.Close()
 	homeContent := helpers.ReaderToString(resp.Body)
@@ -158,6 +162,7 @@ func runServerTest(c *qt.C, config string, args ...string) (result serverTestRes
 		result.publicDirnames[f.Name()] = true
 	}
 
+	result.err = wg.Wait()
 	return
 
 }