generate systemd: do not set `KillMode`

`KillMode=none` has been deprecated in systemd and is now throwing big
warnings when being used.  Users have reported the issues upstream
(see #8615) and on the mailing list.

This deprecation was mainly motivated by an abusive use of third-party
vendors causing all kinds of undesired side-effects.  For instance, busy
mounts that delay reboot.

After talking to the systemd team, we came up with the following plan:

 **Short term**: we can use TimeoutStopSec and remove KillMode=none which
 will default to cgroup.

 **Long term**: we want to change the type to sdnotify. The plumbing for
 Podman is done but we need it for conmon. Once sdnotify is working, we
 can get rid of the pidfile handling etc. and let Podman handle it.
 Michal Seklatar came up with a nice idea that Podman increase the time
 out on demand. That's a much cleaner way than hard-coding the time out
 in the unit as suggest in the short-term solution.

This change is executing the short-term plan and sets a minimum timeout
of 60 seconds.  User-specified timeouts are added to that.

Fixes: #8615
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/pkg/systemd/generate/common.go b/pkg/systemd/generate/common.go
index 52a214883..fb921cd72 100644
--- a/pkg/systemd/generate/common.go
+++ b/pkg/systemd/generate/common.go
@@ -11,6 +11,11 @@ import (
 // is set to the unit's (unique) name.
 const EnvVariable = "PODMAN_SYSTEMD_UNIT"
 
+// minTimeoutStopSec is the minimal stop timeout for generated systemd units.
+// Once exceeded, processes of the services are killed and the cgroup(s) are
+// cleaned up.
+const minTimeoutStopSec = 60
+
 // RestartPolicies includes all valid restart policies to be used in a unit
 // file.
 var RestartPolicies = []string{"no", "on-success", "on-failure", "on-abnormal", "on-watchdog", "on-abort", "always"}