libpod: improve check to create conmon cgroup

commit 1951ff168a introduced a check so
that conmon is not moved to a new cgroup when podman is running inside
of a systemd service.  This is helpful to integrate podman in systemd
so that the spawned conmon lives in the same cgroup as the service
that created it.

Unfortunately this breaks when podman daemon is running in a systemd
service since the same check is in place thus all the conmon processes
end up in the same cgroup as the podman daemon.  When the podman
daemon systemd service stops the conmon processes are also terminated
as well as the containers they monitor.

Improve the check to exclude podman running as a daemon.

Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2052697

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

libpod/oci_conmon_linux.go

@@ -1435,7 +1435,7 @@ func (r *ConmonOCIRuntime) moveConmonToCgroupAndSignal(ctr *Container, cmd *exec
 	}
 
 	// $INVOCATION_ID is set by systemd when running as a service.
-	if os.Getenv("INVOCATION_ID") != "" {
+	if ctr.runtime.RemoteURI() == "" && os.Getenv("INVOCATION_ID") != "" {
 		mustCreateCgroup = false
 	}
 

test/system/250-systemd.bats

@@ -362,4 +362,29 @@ EOF
     run_podman 1 pod exists test_pod
 }
 
+@test "podman-system-service containers survive service stop" {
+    skip_if_remote "N/A under podman-remote"
+
+    SERVICE_NAME=podman-service-$(random_string)
+    port=$(random_free_port)
+    URL=tcp://127.0.0.1:$port
+
+    systemd-run --unit=$SERVICE_NAME $PODMAN system service $URL --time=0
+    wait_for_port 127.0.0.1 $port
+
+    # Start a long-running container.
+    cname=keeps-running
+    run_podman --url $URL run -d --name $cname $IMAGE top -d 2
+
+    run_podman container inspect -l --format "{{.State.Running}}"
+    is "$output" "true" "This should never fail"
+
+    systemctl stop $SERVICE_NAME
+
+    run_podman container inspect $cname --format "{{.State.Running}}"
+    is "$output" "true" "Container is still running after podman server stops"
+
+    run_podman rm -f -t 0 $cname
+}
+
 # vim: filetype=sh

test/system/helpers.systemd.bash

@@ -28,3 +28,7 @@ systemctl() {
 journalctl() {
     command journalctl $_DASHUSER "$@"
 }
+
+systemd-run() {
+    command systemd-run $_DASHUSER "$@";
+}