From c22f3e8b4e2593ca81d08924889f7e7251c83089 Mon Sep 17 00:00:00 2001 From: Daniel J Walsh Date: Wed, 24 Mar 2021 07:49:29 -0400 Subject: Implement SD-NOTIFY proxy in conmon This leverages conmon's ability to proxy the SD-NOTIFY socket. This prevents locking caused by OCI runtime blocking, waiting for SD-NOTIFY messages, and instead passes the messages directly up to the host. NOTE: Also re-enable the auto-update tests which has been disabled due to flakiness. With this change, Podman properly integrates into systemd. Fixes: #7316 Signed-off-by: Joseph Gooch Signed-off-by: Daniel J Walsh Signed-off-by: Valentin Rothberg --- libpod/oci_conmon_linux.go | 49 ++++++++++++++++++++++++++++------------------ 1 file changed, 30 insertions(+), 19 deletions(-) (limited to 'libpod/oci_conmon_linux.go') diff --git a/libpod/oci_conmon_linux.go b/libpod/oci_conmon_linux.go index 846d3815a..ff25be234 100644 --- a/libpod/oci_conmon_linux.go +++ b/libpod/oci_conmon_linux.go @@ -364,11 +364,6 @@ func (r *ConmonOCIRuntime) StartContainer(ctr *Container) error { return err } env := []string{fmt.Sprintf("XDG_RUNTIME_DIR=%s", runtimeDir)} - if ctr.config.SdNotifyMode == define.SdNotifyModeContainer { - if notify, ok := os.LookupEnv("NOTIFY_SOCKET"); ok { - env = append(env, fmt.Sprintf("NOTIFY_SOCKET=%s", notify)) - } - } if path, ok := os.LookupEnv("PATH"); ok { env = append(env, fmt.Sprintf("PATH=%s", path)) } @@ -1014,12 +1009,6 @@ func (r *ConmonOCIRuntime) createOCIContainer(ctr *Container, restoreOptions *Co } } - if ctr.config.SdNotifyMode == define.SdNotifyModeIgnore { - if err := os.Unsetenv("NOTIFY_SOCKET"); err != nil { - logrus.Warnf("Error unsetting NOTIFY_SOCKET %v", err) - } - } - pidfile := ctr.config.PidFile if pidfile == "" { pidfile = filepath.Join(ctr.state.RunDir, "pidfile") @@ -1027,6 +1016,10 @@ func (r *ConmonOCIRuntime) createOCIContainer(ctr *Container, restoreOptions *Co args := r.sharedConmonArgs(ctr, ctr.ID(), ctr.bundlePath(), pidfile, ctr.LogPath(), r.exitsDir, ociLog, ctr.LogDriver(), logTag) + if ctr.config.SdNotifyMode == define.SdNotifyModeContainer && ctr.notifySocket != "" { + args = append(args, fmt.Sprintf("--sdnotify-socket=%s", ctr.notifySocket)) + } + if ctr.config.Spec.Process.Terminal { args = append(args, "-t") } else if ctr.config.Stdin { @@ -1171,7 +1164,8 @@ func (r *ConmonOCIRuntime) createOCIContainer(ctr *Container, restoreOptions *Co } } - err = startCommandGivenSelinux(cmd) + err = startCommandGivenSelinux(cmd, ctr) + // regardless of whether we errored or not, we no longer need the children pipes childSyncPipe.Close() childStartPipe.Close() @@ -1203,7 +1197,13 @@ func (r *ConmonOCIRuntime) createOCIContainer(ctr *Container, restoreOptions *Co // conmon not having a pid file is a valid state, so don't set it if we don't have it logrus.Infof("Got Conmon PID as %d", conmonPID) ctr.state.ConmonPID = conmonPID - if ctr.config.SdNotifyMode != define.SdNotifyModeIgnore { + + // Send the MAINPID via sdnotify if needed. + switch ctr.config.SdNotifyMode { + case define.SdNotifyModeContainer, define.SdNotifyModeIgnore: + // Nothing to do or conmon takes care of it already. + + default: if sent, err := daemon.SdNotify(false, fmt.Sprintf("MAINPID=%d", conmonPID)); err != nil { logrus.Errorf("Error notifying systemd of Conmon PID: %v", err) } else if sent { @@ -1239,11 +1239,6 @@ func (r *ConmonOCIRuntime) configureConmonEnv(ctr *Container, runtimeDir string) } extraFiles := make([]*os.File, 0) - if ctr.config.SdNotifyMode == define.SdNotifyModeContainer { - if notify, ok := os.LookupEnv("NOTIFY_SOCKET"); ok { - env = append(env, fmt.Sprintf("NOTIFY_SOCKET=%s", notify)) - } - } if !r.sdNotify { if listenfds, ok := os.LookupEnv("LISTEN_FDS"); ok { env = append(env, fmt.Sprintf("LISTEN_FDS=%s", listenfds), "LISTEN_PID=1") @@ -1335,7 +1330,23 @@ func (r *ConmonOCIRuntime) sharedConmonArgs(ctr *Container, cuuid, bundlePath, p // startCommandGivenSelinux starts a container ensuring to set the labels of // the process to make sure SELinux doesn't block conmon communication, if SELinux is enabled -func startCommandGivenSelinux(cmd *exec.Cmd) error { +func startCommandGivenSelinux(cmd *exec.Cmd, ctr *Container) error { + // Make sure to unset the NOTIFY_SOCKET and reset if afterwards if needed. + switch ctr.config.SdNotifyMode { + case define.SdNotifyModeContainer, define.SdNotifyModeIgnore: + if ctr.notifySocket != "" { + if err := os.Unsetenv("NOTIFY_SOCKET"); err != nil { + logrus.Warnf("Error unsetting NOTIFY_SOCKET %v", err) + } + + defer func() { + if err := os.Setenv("NOTIFY_SOCKET", ctr.notifySocket); err != nil { + logrus.Errorf("Error resetting NOTIFY_SOCKET=%s", ctr.notifySocket) + } + }() + } + } + if !selinux.GetEnabled() { return cmd.Start() } -- cgit v1.2.3-54-g00ecf