quadlet: add key CgroupsMode

Signed-off-by: Misaki Kasumi <misakikasumi@outlook.com>

docs/source/markdown/podman-systemd.unit.5.md

@@ -259,6 +259,7 @@ Valid options for `[Container]` are listed below:
 | AddDevice=/dev/foo                   | --device /dev/foo                                    |
 | Annotation="XYZ"                     | --annotation "XYZ"                                   |
 | AutoUpdate=registry                  | --label "io.containers.autoupdate=registry"          |
+| CgroupsMode=no-conmon                | --cgroups=no-conmon                                  |
 | ContainerName=name                   | --name name                                          |
 | ContainersConfModule=/etc/nvd\.conf  | --module=/etc/nvd\.conf                              |
 | DNS=192.168.55.1                     | --dns=192.168.55.1                                   |
@@ -370,6 +371,16 @@ Indicates whether the container will be auto-updated ([podman-auto-update(1)](po
 
 * `local`: Tells Podman to compare the image a container is using to the image with its raw name in local storage. If an image is updated locally, Podman simply restarts the systemd unit executing the container.
 
+### `CgroupsMode=`
+
+The cgroups mode of the Podman container. Equivalent to the Podman `--cgroups` option.
+
+By default, the cgroups mode of the container created by Quadlet is `split`,
+which differs from the default (`enabled`) used by the Podman CLI.
+
+If the container joins a pod (i.e. `Pod=` is specified), you may want to change this to
+`no-conmon` or `enabled` so that pod level cgroup resource limits can take effect.
+
 ### `ContainerName=`
 
 The (optional) name of the Podman container. If this is not specified, the default value

pkg/systemd/quadlet/quadlet.go

@@ -62,6 +62,7 @@ const (
 	KeyAuthFile              = "AuthFile"
 	KeyAutoUpdate            = "AutoUpdate"
 	KeyCertDir               = "CertDir"
+	KeyCgroupsMode           = "CgroupsMode"
 	KeyConfigMap             = "ConfigMap"
 	KeyContainerName         = "ContainerName"
 	KeyContainersConfModule  = "ContainersConfModule"
@@ -191,6 +192,7 @@ var (
 		KeyAddDevice:             true,
 		KeyAnnotation:            true,
 		KeyAutoUpdate:            true,
+		KeyCgroupsMode:           true,
 		KeyContainerName:         true,
 		KeyContainersConfModule:  true,
 		KeyDNS:                   true,
@@ -581,7 +583,12 @@ func ConvertContainer(container *parser.UnitFile, isUser bool, unitsInfoMap map[
 
 	// We delegate groups to the runtime
 	service.Add(ServiceGroup, "Delegate", "yes")
-	podman.add("--cgroups=split")
+
+	if cgroupsMode, ok := container.Lookup(ContainerGroup, KeyCgroupsMode); ok && len(cgroupsMode) > 0 {
+		podman.addf("--cgroups=%s", cgroupsMode)
+	} else {
+		podman.add("--cgroups=split")
+	}
 
 	timezone, ok := container.Lookup(ContainerGroup, KeyTimezone)
 	if ok && len(timezone) > 0 {

test/e2e/quadlet/cgroups-mode.container

@@ -0,0 +1,5 @@
+## assert-podman-args --cgroups=no-conmon
+
+[Container]
+Image=localhost/imagename
+CgroupsMode=no-conmon

test/e2e/quadlet_test.go

@@ -897,6 +897,7 @@ BOGUS=foo
 		Entry("template@instance.container", "template@instance.container"),
 		Entry("Unit After Override", "unit-after-override.container"),
 		Entry("NetworkAlias", "network-alias.container"),
+		Entry("CgroupMode", "cgroups-mode.container"),
 
 		Entry("basic.volume", "basic.volume"),
 		Entry("device-copy.volume", "device-copy.volume"),