Merge pull request #4269 from giuseppe/do-not-set-lingering-mode-by-default

rootless: do not enable lingering mode

4 files changed, 22 insertions, 117 deletions

diff --git a/libpod/runtime.go b/libpod/runtime.go
index a0cf0ad7c..107e8e3d0 100644
--- a/libpod/runtime.go
+++ b/libpod/runtime.go
@@ -14,7 +14,6 @@ import (
 	"strings"
 	"sync"
 	"syscall"
-	"time"
 
 	"github.com/BurntSushi/toml"
 	is "github.com/containers/image/v4/storage"
@@ -353,10 +352,6 @@ func defaultRuntimeConfig() (RuntimeConfig, error) {
 // SetXdgDirs ensures the XDG_RUNTIME_DIR env and XDG_CONFIG_HOME variables are set.
 // containers/image uses XDG_RUNTIME_DIR to locate the auth file, XDG_CONFIG_HOME is
 // use for the libpod.conf configuration file.
-// SetXdgDirs internally calls EnableLinger() so that the user's processes are not
-// killed once the session is terminated.  EnableLinger() also attempts to
-// get the runtime directory when XDG_RUNTIME_DIR is not specified.
-// This function should only be called when running rootless.
 func SetXdgDirs() error {
 	if !rootless.IsRootless() {
 		return nil
@@ -365,21 +360,6 @@ func SetXdgDirs() error {
 	// Setup XDG_RUNTIME_DIR
 	runtimeDir := os.Getenv("XDG_RUNTIME_DIR")
 
-	runtimeDirLinger, err := rootless.EnableLinger()
-	if err != nil {
-		return errors.Wrapf(err, "error enabling user session")
-	}
-	if runtimeDir == "" && runtimeDirLinger != "" {
-		if _, err := os.Stat(runtimeDirLinger); err != nil && os.IsNotExist(err) {
-			chWait := make(chan error)
-			defer close(chWait)
-			if _, err := WaitForFile(runtimeDirLinger, chWait, time.Second*10); err != nil {
-				return errors.Wrapf(err, "waiting for directory '%s'", runtimeDirLinger)
-			}
-		}
-		runtimeDir = runtimeDirLinger
-	}
-
 	if runtimeDir == "" {
 		var err error
 		runtimeDir, err = util.GetRuntimeDir()
@@ -400,10 +380,11 @@ func SetXdgDirs() error {
 
 	// Setup XDG_CONFIG_HOME
 	if cfgHomeDir := os.Getenv("XDG_CONFIG_HOME"); cfgHomeDir == "" {
-		if cfgHomeDir, err = util.GetRootlessConfigHomeDir(); err != nil {
+		cfgHomeDir, err := util.GetRootlessConfigHomeDir()
+		if err != nil {
 			return err
 		}
-		if err = os.Setenv("XDG_CONFIG_HOME", cfgHomeDir); err != nil {
+		if err := os.Setenv("XDG_CONFIG_HOME", cfgHomeDir); err != nil {
 			return errors.Wrapf(err, "cannot set XDG_CONFIG_HOME")
 		}
 	}
diff --git a/pkg/rootless/rootless_linux.go b/pkg/rootless/rootless_linux.go
index 59f2880c3..94c42f7d0 100644
--- a/pkg/rootless/rootless_linux.go
+++ b/pkg/rootless/rootless_linux.go
@@ -11,16 +11,13 @@ import (
 	"os/exec"
 	gosignal "os/signal"
 	"os/user"
-	"path/filepath"
 	"runtime"
 	"strconv"
-	"strings"
 	"sync"
 	"unsafe"
 
 	"github.com/containers/libpod/pkg/errorhandling"
 	"github.com/containers/storage/pkg/idtools"
-	"github.com/godbus/dbus"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 	"golang.org/x/sys/unix"
@@ -212,92 +209,6 @@ func getUserNSFirstChild(fd uintptr) (*os.File, error) {
 	}
 }
 
-// EnableLinger configures the system to not kill the user processes once the session
-// terminates
-func EnableLinger() (string, error) {
-	uid := fmt.Sprintf("%d", GetRootlessUID())
-
-	conn, err := dbus.SystemBus()
-	if err == nil {
-		defer func() {
-			if err := conn.Close(); err != nil {
-				logrus.Errorf("unable to close dbus connection: %q", err)
-			}
-		}()
-	}
-
-	lingerEnabled := false
-
-	// If we have a D-BUS connection, attempt to read the LINGER property from it.
-	if conn != nil {
-		path := dbus.ObjectPath(fmt.Sprintf("/org/freedesktop/login1/user/_%s", uid))
-		ret, err := conn.Object("org.freedesktop.login1", path).GetProperty("org.freedesktop.login1.User.Linger")
-		if err == nil && ret.Value().(bool) {
-			lingerEnabled = true
-		}
-	}
-
-	xdgRuntimeDir := os.Getenv("XDG_RUNTIME_DIR")
-	lingerFile := ""
-	if xdgRuntimeDir != "" && !lingerEnabled {
-		lingerFile = filepath.Join(xdgRuntimeDir, "libpod/linger")
-		_, err := os.Stat(lingerFile)
-		if err == nil {
-			lingerEnabled = true
-		}
-	}
-
-	if !lingerEnabled {
-		// First attempt with D-BUS, if it fails, then attempt with "loginctl enable-linger"
-		if conn != nil {
-			o := conn.Object("org.freedesktop.login1", "/org/freedesktop/login1")
-			ret := o.Call("org.freedesktop.login1.Manager.SetUserLinger", 0, uint32(GetRootlessUID()), true, true)
-			if ret.Err == nil {
-				lingerEnabled = true
-			}
-		}
-		if !lingerEnabled {
-			err := exec.Command("loginctl", "enable-linger", uid).Run()
-			if err == nil {
-				lingerEnabled = true
-			} else {
-				logrus.Debugf("cannot run `loginctl enable-linger` for the current user: %v", err)
-			}
-		}
-		if lingerEnabled && lingerFile != "" {
-			f, err := os.Create(lingerFile)
-			if err == nil {
-				if err := f.Close(); err != nil {
-					logrus.Errorf("failed to close %s", f.Name())
-				}
-			} else {
-				logrus.Debugf("could not create linger file: %v", err)
-			}
-		}
-	}
-
-	if !lingerEnabled {
-		return "", nil
-	}
-
-	// If we have a D-BUS connection, attempt to read the RUNTIME PATH from it.
-	if conn != nil {
-		path := dbus.ObjectPath(fmt.Sprintf("/org/freedesktop/login1/user/_%s", uid))
-		ret, err := conn.Object("org.freedesktop.login1", path).GetProperty("org.freedesktop.login1.User.RuntimePath")
-		if err == nil {
-			return strings.Trim(ret.String(), "\"\n"), nil
-		}
-	}
-
-	// If XDG_RUNTIME_DIR is not set and the D-BUS call didn't work, try to get the runtime path with "loginctl"
-	output, err := exec.Command("loginctl", "-pRuntimePath", "show-user", uid).Output()
-	if err != nil {
-		logrus.Debugf("could not get RuntimePath using loginctl: %v", err)
-		return "", nil
-	}
-	return strings.Trim(strings.Replace(string(output), "RuntimePath=", "", -1), "\"\n"), nil
-}
-
 // joinUserAndMountNS re-exec podman in a new userNS and join the user and mount
 // namespace of the specified PID without looking up its parent.  Useful to join directly
 // the conmon process.
diff --git a/pkg/rootless/rootless_unsupported.go b/pkg/rootless/rootless_unsupported.go
index ce488f364..1499b737f 100644
--- a/pkg/rootless/rootless_unsupported.go
+++ b/pkg/rootless/rootless_unsupported.go
@@ -37,12 +37,6 @@ func GetRootlessGID() int {
 	return -1
 }
 
-// EnableLinger configures the system to not kill the user processes once the session
-// terminates
-func EnableLinger() (string, error) {
-	return "", nil
-}
-
 // TryJoinFromFilePaths attempts to join the namespaces of the pid files in paths.
 // This is useful when there are already running containers and we
 // don't have a pause process yet.  We can use the paths to the conmon
diff --git a/troubleshooting.md b/troubleshooting.md
index 6fed719f7..c4e577645 100644
--- a/troubleshooting.md
+++ b/troubleshooting.md
@@ -410,3 +410,22 @@ You'll need to either:
 
 * configure the host to use cgroups v1
 * update the image to use an updated version of systemd.
+
+### 17) rootless containers exit once the user session exits
+
+
+You need to set lingering mode through loginctl to prevent user processes to be killed once
+the user session completed.
+
+#### Symptom
+
+Once the user logs out all the containers exit.
+
+#### Solution
+You'll need to either:
+
+* loginctl enable-linger $UID
+
+or as root if your user has not enough privileges.
+
+* sudo loginctl enable-linger $UID