Added --follow-retry/-F for docker logs

api/client/commands.go

@@ -1760,10 +1760,11 @@ func (cli *DockerCli) CmdDiff(args ...string) error {
 
 func (cli *DockerCli) CmdLogs(args ...string) error {
 	var (
-		cmd    = cli.Subcmd("logs", "CONTAINER", "Fetch the logs of a container")
-		follow = cmd.Bool([]string{"f", "-follow"}, false, "Follow log output")
-		times  = cmd.Bool([]string{"t", "-timestamps"}, false, "Show timestamps")
-		tail   = cmd.String([]string{"-tail"}, "all", "Output the specified number of lines at the end of logs (defaults to all logs)")
+		cmd         = cli.Subcmd("logs", "CONTAINER", "Fetch the logs of a container")
+		follow      = cmd.Bool([]string{"f", "-follow"}, false, "Follow log output")
+		followRetry = cmd.Bool([]string{"F", "-follow-retry"}, false, "Follow log output and retry to follow on container stop")
+		times       = cmd.Bool([]string{"t", "-timestamps"}, false, "Show timestamps")
+		tail        = cmd.String([]string{"-tail"}, "all", "Output the specified number of lines at the end of logs (defaults to all logs)")
 	)
 
 	if err := cmd.Parse(args); err != nil {
@@ -1797,6 +1798,9 @@ func (cli *DockerCli) CmdLogs(args ...string) error {
 	if *follow {
 		v.Set("follow", "1")
 	}
+	if *followRetry {
+		v.Set("follow_retry", "1")
+	}
 	v.Set("tail", *tail)
 
 	return cli.streamHelper("GET", "/containers/"+name+"/logs?"+v.Encode(), env.GetSubEnv("Config").GetBool("Tty"), nil, cli.out, cli.err, nil)

api/server/server.go

@@ -380,6 +380,7 @@ func getContainersLogs(eng *engine.Engine, version version.Version, w http.Respo
 		return err
 	}
 	logsJob.Setenv("follow", r.Form.Get("follow"))
+	logsJob.Setenv("follow_retry", r.Form.Get("follow_retry"))
 	logsJob.Setenv("tail", r.Form.Get("tail"))
 	logsJob.Setenv("stdout", r.Form.Get("stdout"))
 	logsJob.Setenv("stderr", r.Form.Get("stderr"))

daemon/delete.go

@@ -62,6 +62,8 @@ func (daemon *Daemon) ContainerRm(job *engine.Job) engine.Status {
 		if err := daemon.Destroy(container); err != nil {
 			return job.Errorf("Cannot destroy container %s: %s", name, err)
 		}
+		container.stdout.Clean()
+		container.stderr.Clean()
 		container.LogEvent("destroy")
 
 		if removeVolume {

daemon/logs.go

@@ -22,14 +22,15 @@ func (daemon *Daemon) ContainerLogs(job *engine.Job) engine.Status {
 	}
 
 	var (
-		name   = job.Args[0]
-		stdout = job.GetenvBool("stdout")
-		stderr = job.GetenvBool("stderr")
-		tail   = job.Getenv("tail")
-		follow = job.GetenvBool("follow")
-		times  = job.GetenvBool("timestamps")
-		lines  = -1
-		format string
+		name         = job.Args[0]
+		stdout       = job.GetenvBool("stdout")
+		stderr       = job.GetenvBool("stderr")
+		tail         = job.Getenv("tail")
+		follow       = job.GetenvBool("follow")
+		follow_retry = job.GetenvBool("follow_retry")
+		times        = job.GetenvBool("timestamps")
+		lines        = -1
+		format       string
 	)
 	if !(stdout || stderr) {
 		return job.Errorf("You must choose at least one stream")
@@ -111,23 +112,33 @@ func (daemon *Daemon) ContainerLogs(job *engine.Job) engine.Status {
 			}
 		}
 	}
-	if follow && container.IsRunning() {
-		errors := make(chan error, 2)
-		if stdout {
-			stdoutPipe := container.StdoutLogPipe()
-			go func() {
-				errors <- jsonlog.WriteLog(stdoutPipe, job.Stdout, format)
-			}()
-		}
-		if stderr {
-			stderrPipe := container.StderrLogPipe()
-			go func() {
-				errors <- jsonlog.WriteLog(stderrPipe, job.Stderr, format)
-			}()
-		}
-		err := <-errors
-		if err != nil {
-			log.Errorf("%s", err)
+	if (follow && container.IsRunning()) || follow_retry {
+		var stdoutPipe, stderrPipe io.ReadCloser
+		for {
+			errors := make(chan error, 2)
+			if stdout {
+				stdoutPipe = container.StdoutLogPipe()
+				go func() {
+					errors <- jsonlog.WriteLog(stdoutPipe, job.Stdout, format)
+				}()
+			}
+			if stderr {
+				stderrPipe = container.StderrLogPipe()
+				go func() {
+					errors <- jsonlog.WriteLog(stderrPipe, job.Stderr, format)
+				}()
+			}
+			err := <-errors
+			if err != nil {
+				log.Errorf("%s", err)
+			}
+			if follow_retry && daemon.Get(name) != nil {
+				// container still exists, recreate pipes
+				stdoutPipe.Close()
+				stderrPipe.Close()
+				continue
+			}
+			break
 		}
 	}
 	return engine.StatusOK

docs/man/docker-logs.1.md

@@ -7,6 +7,7 @@ docker-logs - Fetch the logs of a container
 # SYNOPSIS
 **docker logs**
 [**-f**|**--follow**[=*false*]]
+[**-F**|**--follow-retry**[=*false*]]
 [**-t**|**--timestamps**[=*false*]]
 [**--tail**[=*"all"*]]
 CONTAINER
@@ -25,6 +26,9 @@ then continue streaming new output from the container’s stdout and stderr.
 **-f**, **--follow**=*true*|*false*
    Follow log output. The default is *false*.
 
+**-F**, **--follow-retry**=*true*|*false*
+    Follow log output and retry to follow on container stop. The default is *false*.
+
 **-t**, **--timestamps**=*true*|*false*
    Show timestamps. The default is *false*.
 

docs/sources/reference/api/docker_remote_api.md

@@ -34,6 +34,11 @@ You can still call an old version of the API using
 
 ### What's new
 
+`GET /containers/(id)/logs`
+
+**New!**
+New parameter `follow_retry` allows to follow logs until container is deleted.
+
 ## v1.14
 
 ### Full Documentation

docs/sources/reference/api/docker_remote_api_v1.15.md

@@ -308,7 +308,7 @@ Get stdout and stderr logs from the container ``id``
 
     **Example request**:
 
-       GET /containers/4fa6e0f0c678/logs?stderr=1&stdout=1&timestamps=1&follow=1&tail=10 HTTP/1.1
+       GET /containers/4fa6e0f0c678/logs?stderr=1&stdout=1&timestamps=1&follow=1&tail=10&follow_retry=1 HTTP/1.1
 
     **Example response**:
 
@@ -322,6 +322,8 @@ Get stdout and stderr logs from the container ``id``
 
 
     -   **follow** – 1/True/true or 0/False/false, return stream. Default false
+    -   **follow_retry** – 1/True/true or 0/False/false, return stream, which follows
+        until container destruction. Default false
     -   **stdout** – 1/True/true or 0/False/false, show stdout log. Default false
     -   **stderr** – 1/True/true or 0/False/false, show stderr log. Default false
     -   **timestamps** – 1/True/true or 0/False/false, print timestamps for

docs/sources/reference/commandline/cli.md

@@ -746,6 +746,7 @@ For example:
 
     Fetch the logs of a container
 
+      -F, --follow-retry=false  Follow log output and retry to follow on container stop
       -f, --follow=false        Follow log output
       -t, --timestamps=false    Show timestamps
       --tail="all"              Output the specified number of lines at the end of logs (defaults to all logs)
@@ -762,6 +763,8 @@ The `docker logs --timestamp` commands will add an RFC3339Nano
 timestamp, for example `2014-05-10T17:42:14.999999999Z07:00`, to each
 log entry.
 
+With `-F` logs will be followed until container will be destroyed.
+
 ## port
 
     Usage: docker port CONTAINER [PRIVATE_PORT[/PROTO]]

integration-cli/docker_cli_logs_test.go

@@ -1,7 +1,9 @@
 package main
 
 import (
+	"bufio"
 	"fmt"
+	"io/ioutil"
 	"os/exec"
 	"regexp"
 	"strings"
@@ -245,3 +247,73 @@ func TestLogsFollowStopped(t *testing.T) {
 	deleteContainer(cleanedContainerID)
 	logDone("logs - logs follow stopped container")
 }
+
+func TestLogsFollowRetry(t *testing.T) {
+	msg := "follow_retry"
+	runCmd := exec.Command(dockerBinary, "run", "-d", "busybox", "sh", "-c", fmt.Sprintf("echo %s", msg))
+	out, _, _, err := runCommandWithStdoutStderr(runCmd)
+	errorOut(err, t, fmt.Sprintf("run failed with errors: %v", err))
+
+	cleanedContainerID := stripTrailingCharacters(out)
+	exec.Command(dockerBinary, "wait", cleanedContainerID).Run()
+
+	// TODO: this should be replaced with waitForContainer
+	time.Sleep(500 * time.Millisecond)
+
+	logsCmd := exec.Command(dockerBinary, "logs", "-F", cleanedContainerID)
+	stdout, err := logsCmd.StdoutPipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+	stderr, err := logsCmd.StderrPipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := logsCmd.Start(); err != nil {
+		t.Fatal(err)
+	}
+
+	w := make(chan struct{})
+	go func() {
+		s := bufio.NewScanner(stdout)
+		count := 0
+		for s.Scan() {
+			count++
+			if s.Text() != msg {
+				t.Fatalf("Log line should be %q, got %q", msg, s.Text())
+			}
+		}
+		if err := s.Err(); err != nil {
+			t.Fatal(err)
+		}
+		if count != 3 {
+			res, _ := ioutil.ReadAll(stderr)
+			t.Logf("%s", res)
+			t.Fatalf("Should be 3 lines in log, got %d", count)
+		}
+		if err := logsCmd.Wait(); err != nil {
+			t.Fatal(err)
+		}
+		close(w)
+	}()
+
+	if err := exec.Command(dockerBinary, "start", cleanedContainerID).Run(); err != nil {
+		t.Fatal(err)
+	}
+	exec.Command(dockerBinary, "wait", cleanedContainerID).Run()
+	if err := exec.Command(dockerBinary, "start", cleanedContainerID).Run(); err != nil {
+		t.Fatal(err)
+	}
+	exec.Command(dockerBinary, "wait", cleanedContainerID).Run()
+	if err := exec.Command(dockerBinary, "rm", cleanedContainerID).Run(); err != nil {
+		t.Fatal(err)
+	}
+
+	select {
+	case <-w:
+	case <-time.After(5 * time.Second):
+		t.Fatal("logs -F didn't exit after container remove")
+	}
+
+	logDone("logs - follow-retry")
+}