podman logs honor stderr correctly

Make the ContainerLogsOptions support two io.Writers,
one for stdout and the other for stderr. The logline already
includes the information to which Writer it has to be written.

Signed-off-by: Paul Holzinger <paul.holzinger@web.de>

cmd/podman/containers/logs.go

@@ -122,6 +122,7 @@ func logs(_ *cobra.Command, args []string) error {
 		}
 		logsOptions.Since = since
 	}
-	logsOptions.Writer = os.Stdout
+	logsOptions.StdoutWriter = os.Stdout
+	logsOptions.StderrWriter = os.Stderr
 	return registry.ContainerEngine().ContainerLogs(registry.GetContext(), args, logsOptions.ContainerLogsOptions)
 }

libpod/logs/log.go

@@ -210,3 +210,19 @@ func NewLogLine(line string) (*LogLine, error) {
 func (l *LogLine) Partial() bool {
 	return l.ParseLogType == PartialLogType
 }
+
+func (l *LogLine) Write(stdout io.Writer, stderr io.Writer, logOpts *LogOptions) {
+	switch l.Device {
+	case "stdout":
+		if stdout != nil {
+			fmt.Fprintln(stdout, l.String(logOpts))
+		}
+	case "stderr":
+		if stderr != nil {
+			fmt.Fprintln(stderr, l.String(logOpts))
+		}
+	default:
+		// Warn the user if the device type does not match. Most likely the file is corrupted.
+		logrus.Warnf("unknown Device type '%s' in log file from Container %s", l.Device, l.CID)
+	}
+}

pkg/domain/entities/containers.go

@@ -227,8 +227,10 @@ type ContainerLogsOptions struct {
 	Tail int64
 	// Show timestamps in the logs.
 	Timestamps bool
-	// Write the logs to Writer.
-	Writer io.Writer
+	// Write the stdout to this Writer.
+	StdoutWriter io.Writer
+	// Write the stderr to this Writer.
+	StderrWriter io.Writer
 }
 
 // ExecOptions describes the cli values to exec into

pkg/domain/infra/abi/containers.go

@@ -925,7 +925,7 @@ func (ic *ContainerEngine) ContainerRun(ctx context.Context, opts entities.Conta
 }
 
 func (ic *ContainerEngine) ContainerLogs(ctx context.Context, containers []string, options entities.ContainerLogsOptions) error {
-	if options.Writer == nil {
+	if options.StdoutWriter == nil && options.StderrWriter == nil {
 		return errors.New("no io.Writer set for container logs")
 	}
 
@@ -963,7 +963,7 @@ func (ic *ContainerEngine) ContainerLogs(ctx context.Context, containers []strin
 	}()
 
 	for line := range logChannel {
-		fmt.Fprintln(options.Writer, line.String(logOpts))
+		line.Write(options.StdoutWriter, options.StderrWriter, logOpts)
 	}
 
 	return nil

pkg/domain/infra/tunnel/containers.go

@@ -360,11 +360,12 @@ func (ic *ContainerEngine) ContainerCreate(ctx context.Context, s *specgen.SpecG
 func (ic *ContainerEngine) ContainerLogs(_ context.Context, nameOrIDs []string, options entities.ContainerLogsOptions) error {
 	since := options.Since.Format(time.RFC3339)
 	tail := strconv.FormatInt(options.Tail, 10)
-	stdout := options.Writer != nil
+	stdout := options.StdoutWriter != nil
+	stderr := options.StderrWriter != nil
 	opts := containers.LogOptions{
 		Follow:     &options.Follow,
 		Since:      &since,
-		Stderr:     &stdout,
+		Stderr:     &stderr,
 		Stdout:     &stdout,
 		Tail:       &tail,
 		Timestamps: &options.Timestamps,
@@ -372,10 +373,11 @@ func (ic *ContainerEngine) ContainerLogs(_ context.Context, nameOrIDs []string,
 	}
 
 	var err error
-	outCh := make(chan string)
+	stdoutCh := make(chan string)
+	stderrCh := make(chan string)
 	ctx, cancel := context.WithCancel(context.Background())
 	go func() {
-		err = containers.Logs(ic.ClientCxt, nameOrIDs[0], opts, outCh, outCh)
+		err = containers.Logs(ic.ClientCxt, nameOrIDs[0], opts, stdoutCh, stderrCh)
 		cancel()
 	}()
 
@@ -383,8 +385,14 @@ func (ic *ContainerEngine) ContainerLogs(_ context.Context, nameOrIDs []string,
 		select {
 		case <-ctx.Done():
 			return err
-		case line := <-outCh:
-			_, _ = io.WriteString(options.Writer, line+"\n")
+		case line := <-stdoutCh:
+			if options.StdoutWriter != nil {
+				_, _ = io.WriteString(options.StdoutWriter, line+"\n")
+			}
+		case line := <-stderrCh:
+			if options.StderrWriter != nil {
+				_, _ = io.WriteString(options.StderrWriter, line+"\n")
+			}
 		}
 	}
 }

test/e2e/logs_test.go

@@ -355,4 +355,21 @@ var _ = Describe("Podman logs", func() {
 		Expect(outlines[0]).To(Equal("1\r"))
 		Expect(outlines[1]).To(Equal("2\r"))
 	})
+
+	It("podman logs test stdout and stderr", func() {
+		cname := "log-test"
+		logc := podmanTest.Podman([]string{"run", "--name", cname, ALPINE, "sh", "-c", "echo stdout; echo stderr >&2"})
+		logc.WaitWithDefaultTimeout()
+		Expect(logc).To(Exit(0))
+
+		wait := podmanTest.Podman([]string{"wait", cname})
+		wait.WaitWithDefaultTimeout()
+		Expect(wait).To(Exit(0))
+
+		results := podmanTest.Podman([]string{"logs", cname})
+		results.WaitWithDefaultTimeout()
+		Expect(results).To(Exit(0))
+		Expect(results.OutputToString()).To(Equal("stdout"))
+		Expect(results.ErrorToString()).To(Equal("stderr"))
+	})
 })

test/e2e/play_kube_test.go

@@ -1072,7 +1072,7 @@ var _ = Describe("Podman play kube", func() {
 		logs := podmanTest.Podman([]string{"logs", getCtrNameInPod(pod)})
 		logs.WaitWithDefaultTimeout()
 		Expect(logs.ExitCode()).To(Equal(0))
-		Expect(logs.OutputToString()).To(ContainSubstring("Operation not permitted"))
+		Expect(logs.ErrorToString()).To(ContainSubstring("Operation not permitted"))
 	})
 
 	It("podman play kube seccomp pod level", func() {
@@ -1099,7 +1099,7 @@ var _ = Describe("Podman play kube", func() {
 		logs := podmanTest.Podman([]string{"logs", getCtrNameInPod(pod)})
 		logs.WaitWithDefaultTimeout()
 		Expect(logs.ExitCode()).To(Equal(0))
-		Expect(logs.OutputToString()).To(ContainSubstring("Operation not permitted"))
+		Expect(logs.ErrorToString()).To(ContainSubstring("Operation not permitted"))
 	})
 
 	It("podman play kube with pull policy of never should be 125", func() {

test/e2e/toolbox_test.go

@@ -239,7 +239,7 @@ var _ = Describe("Toolbox-specific testing", func() {
 		session = podmanTest.Podman([]string{"logs", "test"})
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
-		Expect(session.OutputToString()).To(ContainSubstring(expectedOutput))
+		Expect(session.ErrorToString()).To(ContainSubstring(expectedOutput))
 	})
 
 	It("podman create --userns=keep-id + podman exec - adding group with groupadd", func() {