podman-varlink: log timeouts

The default timeout of one second when using podman-varlink can confuse
users as podman exits in silence after this timeout in case no
connection to the endpoint is alive.  Print a log (info level) that the
varlink service has expired to guide the user.

This change requires to vendor in the latest master of varlink/go.

Signed-off-by: Valentin Rothberg <vrothberg@suse.com>

Closes: #899
Approved by: rhatdan

cmd/podman/varlink.go

@@ -7,6 +7,7 @@ import (
 	ioprojectatomicpodman "github.com/projectatomic/libpod/cmd/podman/varlink"
 	"github.com/projectatomic/libpod/pkg/varlinkapi"
 	"github.com/projectatomic/libpod/version"
+	"github.com/sirupsen/logrus"
 	"github.com/urfave/cli"
 	"github.com/varlink/go/varlink"
 )
@@ -62,8 +63,14 @@ func varlinkCmd(c *cli.Context) error {
 
 	// Run the varlink server at the given address
 	if err = service.Listen(args[0], timeout); err != nil {
+		switch err.(type) {
+		case varlink.ServiceTimeoutError:
+			logrus.Infof("varlink service expired (use --timeout to increase session time beyond %d ms)", c.Int64("timeout"))
+			return nil
+		default:
 			return errors.Errorf("unable to start varlink service")
 		}
+	}
 
 	return nil
 }

vendor/github.com/containers/storage/pkg/archive/example_changes.go

@@ -1,97 +0,0 @@
-// +build ignore
-
-// Simple tool to create an archive stream from an old and new directory
-//
-// By default it will stream the comparison of two temporary directories with junk files
-package main
-
-import (
-	"flag"
-	"fmt"
-	"io"
-	"io/ioutil"
-	"os"
-	"path"
-
-	"github.com/containers/storage/pkg/archive"
-	"github.com/sirupsen/logrus"
-)
-
-var (
-	flDebug  = flag.Bool("D", false, "debugging output")
-	flNewDir = flag.String("newdir", "", "")
-	flOldDir = flag.String("olddir", "", "")
-	log      = logrus.New()
-)
-
-func main() {
-	flag.Usage = func() {
-		fmt.Println("Produce a tar from comparing two directory paths. By default a demo tar is created of around 200 files (including hardlinks)")
-		fmt.Printf("%s [OPTIONS]\n", os.Args[0])
-		flag.PrintDefaults()
-	}
-	flag.Parse()
-	log.Out = os.Stderr
-	if (len(os.Getenv("DEBUG")) > 0) || *flDebug {
-		logrus.SetLevel(logrus.DebugLevel)
-	}
-	var newDir, oldDir string
-
-	if len(*flNewDir) == 0 {
-		var err error
-		newDir, err = ioutil.TempDir("", "storage-test-newDir")
-		if err != nil {
-			log.Fatal(err)
-		}
-		defer os.RemoveAll(newDir)
-		if _, err := prepareUntarSourceDirectory(100, newDir, true); err != nil {
-			log.Fatal(err)
-		}
-	} else {
-		newDir = *flNewDir
-	}
-
-	if len(*flOldDir) == 0 {
-		oldDir, err := ioutil.TempDir("", "storage-test-oldDir")
-		if err != nil {
-			log.Fatal(err)
-		}
-		defer os.RemoveAll(oldDir)
-	} else {
-		oldDir = *flOldDir
-	}
-
-	changes, err := archive.ChangesDirs(newDir, oldDir)
-	if err != nil {
-		log.Fatal(err)
-	}
-
-	a, err := archive.ExportChanges(newDir, changes)
-	if err != nil {
-		log.Fatal(err)
-	}
-	defer a.Close()
-
-	i, err := io.Copy(os.Stdout, a)
-	if err != nil && err != io.EOF {
-		log.Fatal(err)
-	}
-	fmt.Fprintf(os.Stderr, "wrote archive of %d bytes", i)
-}
-
-func prepareUntarSourceDirectory(numberOfFiles int, targetPath string, makeLinks bool) (int, error) {
-	fileData := []byte("fooo")
-	for n := 0; n < numberOfFiles; n++ {
-		fileName := fmt.Sprintf("file-%d", n)
-		if err := ioutil.WriteFile(path.Join(targetPath, fileName), fileData, 0700); err != nil {
-			return 0, err
-		}
-		if makeLinks {
-			if err := os.Link(path.Join(targetPath, fileName), path.Join(targetPath, fileName+"-link")); err != nil {
-				return 0, err
-			}
-		}
-	}
-	totalSize := numberOfFiles * len(fileData)
-	return totalSize, nil
-}

vendor/github.com/varlink/go/varlink/service.go

@@ -51,6 +51,13 @@ type Service struct {
 	address      string
 }
 
+// ServiceTimoutError helps API users to special-case timeouts.
+type ServiceTimeoutError struct {}
+
+func (ServiceTimeoutError) Error() string {
+	return "service timeout"
+}
+
 func (s *Service) getInfo(c Call) error {
 	return c.replyGetInfo(s.vendor, s.product, s.version, s.url, s.names)
 }
@@ -297,7 +304,7 @@ func (s *Service) Listen(address string, timeout time.Duration) error {
 				s.mutex.Lock()
 				if s.conncounter == 0 {
 					s.mutex.Unlock()
-					return nil
+					return ServiceTimeoutError{}
 				}
 				s.mutex.Unlock()
 				continue