generate systemd: custom stop signal

Commit 9ac5267598c3 changed the type of the generated systemd units from
forking to notify.  Parts of these changes was also removing the need to
pass any information via the file system (e.g., PIDFILE, container ID).
That in turn implies that systemd takes care of stopping the container.

By default, systemd first sends a SIGTERM and after a certain timeout,
it'll send a SIGKILL.  That's pretty much what Podman is doing, unless
the container was created with a custom stop signal which is the case
when the --stop-signal flag was used or systemd is mounted.

Account for that by using systemd's KillSignal option which allows for
changing SIGTERM to another signal.  Also make sure that we're using the
correct timeout for units generated with --new.

Fixes: #11304
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

pkg/systemd/generate/common.go

@@ -8,9 +8,9 @@ import (
 	"github.com/pkg/errors"
 )
 
-// minTimeoutStopSec is the minimal stop timeout for generated systemd units.
+// minTimeoutStopSec is the minimal stop timeout for generated systemd units
-// Once exceeded, processes of the services are killed and the cgroup(s) are
+// without --new.  Once exceeded, processes of the services are killed and the
-// cleaned up.
+// cgroup(s) are cleaned up.
 const minTimeoutStopSec = 60
 
 // validateRestartPolicy checks that the user-provided policy is valid.

pkg/systemd/generate/containers.go

@@ -16,6 +16,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/pflag"
+	"golang.org/x/sys/unix"
 )
 
 // containerInfo contains data required for generating a container's systemd
@@ -32,6 +33,8 @@ type containerInfo struct {
 	// StopTimeout sets the timeout Podman waits before killing the container
 	// during service stop.
 	StopTimeout uint
+	// KillSignal of the container.
+	KillSignal string
 	// RestartPolicy of the systemd unit (e.g., no, on-failure, always).
 	RestartPolicy string
 	// PIDFile of the service. Required for forking services. Must point to the
@@ -102,6 +105,9 @@ Environment={{{{- range $index, $value := .ExtraEnvs -}}}}{{{{if $index}}}} {{{{
 {{{{- end}}}}
 Restart={{{{.RestartPolicy}}}}
 TimeoutStopSec={{{{.TimeoutStopSec}}}}
+{{{{- if .KillSignal}}}}
+KillSignal={{{{.KillSignal}}}}
+{{{{- end}}}}
 {{{{- if .ExecStartPre}}}}
 ExecStartPre={{{{.ExecStartPre}}}}
 {{{{- end}}}}
@@ -184,6 +190,13 @@ func generateContainerInfo(ctr *libpod.Container, options entities.GenerateSyste
 		containerEnv:      envs,
 	}
 
+	// Set a custom kill signal for non SIGTERM (already default in
+	// systemd) signals.
+	stopSignal := ctr.StopSignal()
+	if stopSignal != uint(unix.SIGTERM) {
+		info.KillSignal = fmt.Sprintf("%d", stopSignal)
+	}
+
 	return &info, nil
 }
 
@@ -359,7 +372,15 @@ func executeContainerTemplate(info *containerInfo, options entities.GenerateSyst
 		info.ExecStart = strings.Join(startCommand, " ")
 	}
 
-	info.TimeoutStopSec = minTimeoutStopSec + info.StopTimeout
+	info.TimeoutStopSec = info.StopTimeout
+
+	// For units without --new add an additional 60 seconds to the stop
+	// timeout to make sure that Podman stop has enough time to properly
+	// shutdown and cleanup the container before systemd starts to nuke
+	// everything in the cgroup.
+	if !options.New {
+		info.TimeoutStopSec += minTimeoutStopSec
+	}
 
 	if info.PodmanVersion == "" {
 		info.PodmanVersion = version.Version.String()

pkg/systemd/generate/containers_test.go

@@ -129,7 +129,7 @@ RequiresMountsFor=/var/run/containers/storage
 [Service]
 Environment=PODMAN_SYSTEMD_UNIT=%n
 Restart=always
-TimeoutStopSec=70
+TimeoutStopSec=10
 ExecStart=/usr/bin/podman container run --cgroups=no-conmon --rm --sdnotify=conmon -d --replace --name jadda-jadda --hostname hello-world awesome-image:latest command arg1 ... argN "foo=arg \"with \" space"
 Type=notify
 NotifyAccess=all
@@ -151,7 +151,7 @@ RequiresMountsFor=/var/run/containers/storage
 [Service]
 Environment=PODMAN_SYSTEMD_UNIT=%n
 Restart=always
-TimeoutStopSec=70
+TimeoutStopSec=10
 ExecStart=/usr/bin/podman container run --cgroups=no-conmon --rm -d --replace --sdnotify=container --name jadda-jadda --hostname hello-world awesome-image:latest command arg1 ... argN "foo=arg \"with \" space"
 Type=notify
 NotifyAccess=all
@@ -173,7 +173,7 @@ RequiresMountsFor=/var/run/containers/storage
 [Service]
 Environment=PODMAN_SYSTEMD_UNIT=%n
 Restart=always
-TimeoutStopSec=70
+TimeoutStopSec=10
 ExecStart=/usr/bin/podman run --cgroups=no-conmon --rm --sdnotify=conmon --replace -d --name jadda-jadda --hostname hello-world awesome-image:latest command arg1 ... argN
 Type=notify
 NotifyAccess=all
@@ -195,7 +195,7 @@ RequiresMountsFor=/var/run/containers/storage
 [Service]
 Environment=PODMAN_SYSTEMD_UNIT=%n
 Restart=always
-TimeoutStopSec=70
+TimeoutStopSec=10
 ExecStart=/usr/bin/podman run --cgroups=no-conmon --rm --pod-id-file %t/pod-foobar.pod-id-file --sdnotify=conmon --replace -d --name jadda-jadda --hostname hello-world awesome-image:latest command arg1 ... argN
 Type=notify
 NotifyAccess=all
@@ -217,7 +217,7 @@ RequiresMountsFor=/var/run/containers/storage
 [Service]
 Environment=PODMAN_SYSTEMD_UNIT=%n
 Restart=always
-TimeoutStopSec=70
+TimeoutStopSec=10
 ExecStart=/usr/bin/podman run --cgroups=no-conmon --rm --sdnotify=conmon --replace --detach --name jadda-jadda --hostname hello-world awesome-image:latest command arg1 ... argN
 Type=notify
 NotifyAccess=all
@@ -239,7 +239,7 @@ RequiresMountsFor=/var/run/containers/storage
 [Service]
 Environment=PODMAN_SYSTEMD_UNIT=%n
 Restart=always
-TimeoutStopSec=70
+TimeoutStopSec=10
 ExecStart=/usr/bin/podman run --cgroups=no-conmon --rm --sdnotify=conmon -d awesome-image:latest
 Type=notify
 NotifyAccess=all
@@ -262,7 +262,7 @@ RequiresMountsFor=/var/run/containers/storage
 [Service]
 Environment=PODMAN_SYSTEMD_UNIT=%n
 Restart=always
-TimeoutStopSec=102
+TimeoutStopSec=42
 ExecStart=/usr/bin/podman run --cgroups=no-conmon --rm --sdnotify=conmon ` +
 			detachparam +
 			` awesome-image:latest
@@ -288,7 +288,7 @@ RequiresMountsFor=/var/run/containers/storage
 [Service]
 Environment=PODMAN_SYSTEMD_UNIT=%n
 Restart=always
-TimeoutStopSec=102
+TimeoutStopSec=42
 ExecStart=/usr/bin/podman run --cgroups=no-conmon --rm --sdnotify=conmon -d --replace --name test -p 80:80 awesome-image:latest somecmd --detach=false
 Type=notify
 NotifyAccess=all
@@ -310,7 +310,7 @@ RequiresMountsFor=/var/run/containers/storage
 [Service]
 Environment=PODMAN_SYSTEMD_UNIT=%n
 Restart=always
-TimeoutStopSec=102
+TimeoutStopSec=42
 ExecStart=/usr/bin/podman --events-backend none --runroot /root run --cgroups=no-conmon --rm --sdnotify=conmon -d awesome-image:latest
 Type=notify
 NotifyAccess=all
@@ -332,7 +332,7 @@ RequiresMountsFor=/var/run/containers/storage
 [Service]
 Environment=PODMAN_SYSTEMD_UNIT=%n
 Restart=always
-TimeoutStopSec=70
+TimeoutStopSec=10
 ExecStart=/usr/bin/podman container run --cgroups=no-conmon --rm --sdnotify=conmon -d awesome-image:latest
 Type=notify
 NotifyAccess=all
@@ -354,7 +354,7 @@ RequiresMountsFor=/var/run/containers/storage
 [Service]
 Environment=PODMAN_SYSTEMD_UNIT=%n
 Restart=always
-TimeoutStopSec=70
+TimeoutStopSec=10
 ExecStart=/usr/bin/podman run --cgroups=no-conmon --rm --sdnotify=conmon -d --replace --name test --log-driver=journald --log-opt=tag={{.Name}} awesome-image:latest
 Type=notify
 NotifyAccess=all
@@ -376,7 +376,7 @@ RequiresMountsFor=/var/run/containers/storage
 [Service]
 Environment=PODMAN_SYSTEMD_UNIT=%n
 Restart=always
-TimeoutStopSec=70
+TimeoutStopSec=10
 ExecStart=/usr/bin/podman run --cgroups=no-conmon --rm --sdnotify=conmon -d --replace --name test awesome-image:latest sh -c "kill $$$$ && echo %%\\"
 Type=notify
 NotifyAccess=all
@@ -398,7 +398,7 @@ RequiresMountsFor=/var/run/containers/storage
 [Service]
 Environment=PODMAN_SYSTEMD_UNIT=%n
 Restart=always
-TimeoutStopSec=70
+TimeoutStopSec=10
 ExecStart=/usr/bin/podman run --cgroups=no-conmon --rm --sdnotify=conmon -d --conmon-pidfile=foo --cidfile=foo awesome-image:latest podman run --cgroups=foo --conmon-pidfile=foo --cidfile=foo alpine
 Type=notify
 NotifyAccess=all
@@ -420,7 +420,7 @@ RequiresMountsFor=/var/run/containers/storage
 [Service]
 Environment=PODMAN_SYSTEMD_UNIT=%n
 Restart=always
-TimeoutStopSec=70
+TimeoutStopSec=10
 ExecStart=/usr/bin/podman run --cgroups=no-conmon --rm --pod-id-file %t/pod-foobar.pod-id-file --sdnotify=conmon -d --conmon-pidfile=foo --cidfile=foo awesome-image:latest podman run --cgroups=foo --conmon-pidfile=foo --cidfile=foo --pod-id-file /tmp/pod-foobar.pod-id-file alpine
 Type=notify
 NotifyAccess=all
@@ -443,7 +443,7 @@ RequiresMountsFor=/var/run/containers/storage
 Environment=PODMAN_SYSTEMD_UNIT=%n
 Environment=FOO=abc "BAR=my test" USER=%%a
 Restart=always
-TimeoutStopSec=70
+TimeoutStopSec=10
 ExecStart=/usr/bin/podman run --cgroups=no-conmon --rm --sdnotify=conmon -d --env FOO --env=BAR --env=MYENV=2 -e USER awesome-image:latest
 Type=notify
 NotifyAccess=all

pkg/systemd/generate/pods.go

@@ -323,7 +323,7 @@ func executePodTemplate(info *podInfo, options entities.GenerateSystemdOptions)
 		info.ExecStop = "{{{{.Executable}}}} {{{{if .RootFlags}}}}{{{{ .RootFlags}}}} {{{{end}}}}pod stop --ignore --pod-id-file {{{{.PodIDFile}}}} {{{{if (ge .StopTimeout 0)}}}}-t {{{{.StopTimeout}}}}{{{{end}}}}"
 		info.ExecStopPost = "{{{{.Executable}}}} {{{{if .RootFlags}}}}{{{{ .RootFlags}}}} {{{{end}}}}pod rm --ignore -f --pod-id-file {{{{.PodIDFile}}}}"
 	}
-	info.TimeoutStopSec = minTimeoutStopSec + info.StopTimeout
+	info.TimeoutStopSec = info.StopTimeout
 
 	if info.PodmanVersion == "" {
 		info.PodmanVersion = version.Version.String()

pkg/systemd/generate/pods_test.go

@@ -54,7 +54,7 @@ Before=container-1.service container-2.service
 [Service]
 Environment=PODMAN_SYSTEMD_UNIT=%n
 Restart=always
-TimeoutStopSec=102
+TimeoutStopSec=42
 ExecStart=/usr/bin/podman start jadda-jadda-infra
 ExecStop=/usr/bin/podman stop -t 42 jadda-jadda-infra
 ExecStopPost=/usr/bin/podman stop -t 42 jadda-jadda-infra
@@ -82,7 +82,7 @@ Before=container-1.service container-2.service
 [Service]
 Environment=PODMAN_SYSTEMD_UNIT=%n
 Restart=on-failure
-TimeoutStopSec=70
+TimeoutStopSec=10
 ExecStartPre=/bin/rm -f %t/pod-123abc.pid %t/pod-123abc.pod-id
 ExecStartPre=/usr/bin/podman pod create --infra-conmon-pidfile %t/pod-123abc.pid --pod-id-file %t/pod-123abc.pod-id --name foo "bar=arg with space" --replace
 ExecStart=/usr/bin/podman pod start --pod-id-file %t/pod-123abc.pod-id
@@ -110,7 +110,7 @@ Before=container-1.service container-2.service
 [Service]
 Environment=PODMAN_SYSTEMD_UNIT=%n
 Restart=on-failure
-TimeoutStopSec=70
+TimeoutStopSec=10
 ExecStartPre=/bin/rm -f %t/pod-123abc.pid %t/pod-123abc.pod-id
 ExecStartPre=/usr/bin/podman --events-backend none --runroot /root pod create --infra-conmon-pidfile %t/pod-123abc.pid --pod-id-file %t/pod-123abc.pod-id --name foo "bar=arg with space" --replace
 ExecStart=/usr/bin/podman --events-backend none --runroot /root pod start --pod-id-file %t/pod-123abc.pod-id
@@ -138,7 +138,7 @@ Before=container-1.service container-2.service
 [Service]
 Environment=PODMAN_SYSTEMD_UNIT=%n
 Restart=on-failure
-TimeoutStopSec=70
+TimeoutStopSec=10
 ExecStartPre=/bin/rm -f %t/pod-123abc.pid %t/pod-123abc.pod-id
 ExecStartPre=/usr/bin/podman pod create --infra-conmon-pidfile %t/pod-123abc.pid --pod-id-file %t/pod-123abc.pod-id --name foo --replace
 ExecStart=/usr/bin/podman pod start --pod-id-file %t/pod-123abc.pod-id
@@ -166,7 +166,7 @@ Before=container-1.service container-2.service
 [Service]
 Environment=PODMAN_SYSTEMD_UNIT=%n
 Restart=on-failure
-TimeoutStopSec=70
+TimeoutStopSec=10
 ExecStartPre=/bin/rm -f %t/pod-123abc.pid %t/pod-123abc.pod-id
 ExecStartPre=/usr/bin/podman pod create --infra-conmon-pidfile %t/pod-123abc.pid --pod-id-file %t/pod-123abc.pod-id --name foo --label key={{someval}} --replace
 ExecStart=/usr/bin/podman pod start --pod-id-file %t/pod-123abc.pod-id

test/system/250-systemd.bats

@@ -125,4 +125,17 @@ function service_cleanup() {
     service_cleanup
 }
 
+@test "podman generate systemd - stop-signal" {
+    cname=$(random_string)
+    run_podman create --name $cname --stop-signal=42 $IMAGE
+    run_podman generate systemd --new $cname
+    is "$output" ".*KillSignal=42.*" "KillSignal is set"
+
+    # Regression test for #11304: systemd wants a custom stop-signal.
+    run_podman rm -f $cname
+    run_podman create --name $cname --systemd=true $IMAGE systemd
+    run_podman generate systemd --new $cname
+    is "$output" ".*KillSignal=37.*" "KillSignal is set"
+}
+
 # vim: filetype=sh