From 0f4e2be0733ac9806b281627b6c8466e61611435 Mon Sep 17 00:00:00 2001 From: Valentin Rothberg Date: Thu, 13 Aug 2020 12:53:28 +0200 Subject: podman.service: use sdnotiy Commit 2b6dd3fb4384 set the killmode of the podman.service to the systemd default which ultimately lead to the problem that systemd will kill *all* processes inside the unit's cgroup and hence kill all containers whenever the service is stopped. Fix it by setting the type to sdnotify and the killmode to process. `podman system service` will send the necessary notify messages when the NOTIFY_SOCKET is set and unset it right after to prevent the backend and container runtimes from jumping in between and send messages as well. Fixes: #7294 Signed-off-by: Valentin Rothberg --- contrib/systemd/system/podman.service | 3 ++- pkg/api/server/server.go | 27 ++++++++++++++++++++++++++- 2 files changed, 28 insertions(+), 2 deletions(-) diff --git a/contrib/systemd/system/podman.service b/contrib/systemd/system/podman.service index c8751168d..e14bbe078 100644 --- a/contrib/systemd/system/podman.service +++ b/contrib/systemd/system/podman.service @@ -6,5 +6,6 @@ Documentation=man:podman-system-service(1) StartLimitIntervalSec=0 [Service] -Type=simple +Type=notify +KillMode=process ExecStart=/usr/bin/podman system service diff --git a/pkg/api/server/server.go b/pkg/api/server/server.go index 18b48a3f6..e7c031234 100644 --- a/pkg/api/server/server.go +++ b/pkg/api/server/server.go @@ -2,6 +2,7 @@ package server import ( "context" + "fmt" "log" "net" "net/http" @@ -17,6 +18,7 @@ import ( "github.com/containers/podman/v2/pkg/api/handlers" "github.com/containers/podman/v2/pkg/api/server/idletracker" "github.com/coreos/go-systemd/v22/activation" + "github.com/coreos/go-systemd/v22/daemon" "github.com/gorilla/mux" "github.com/gorilla/schema" "github.com/pkg/errors" @@ -147,8 +149,31 @@ func newServer(runtime *libpod.Runtime, duration time.Duration, listener *net.Li return &server, nil } -// Serve starts responding to HTTP requests +// If the NOTIFY_SOCKET is set, communicate the PID and readiness, and +// further unset NOTIFY_SOCKET to prevent containers from sending +// messages and unset INVOCATION_ID so conmon and containers are in +// the correct cgroup. +func setupSystemd() { + if len(os.Getenv("NOTIFY_SOCKET")) == 0 { + return + } + payload := fmt.Sprintf("MAINPID=%d", os.Getpid()) + payload += "\n" + payload += daemon.SdNotifyReady + if sent, err := daemon.SdNotify(true, payload); err != nil { + logrus.Errorf("Error notifying systemd of Conmon PID: %s", err.Error()) + } else if sent { + logrus.Debugf("Notify sent successfully") + } + + if err := os.Unsetenv("INVOCATION_ID"); err != nil { + logrus.Errorf("Error unsetting INVOCATION_ID: %s", err.Error()) + } +} + +// Serve starts responding to HTTP requests. func (s *APIServer) Serve() error { + setupSystemd() sigChan := make(chan os.Signal, 1) signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM) errChan := make(chan error, 1) -- cgit v1.2.3-54-g00ecf