optimize cgroups settings for node reserved (#9209)

* optimize cgroups settings for node reserved

* fix

* set cgroup slice for multi container engine

* set cgroup slice for crio

* add reserved cgroups variables to sample files

* Compatible with cgroup path for different container managers

* add cgroups doc

* fix markdown

roles/container-engine/containerd/templates/containerd.service.j2

@@ -36,6 +36,10 @@ LimitMEMLOCK={{ containerd_limit_mem_lock }}
 # Only systemd 226 and above support this version.
 TasksMax=infinity
 OOMScoreAdjust=-999
+# Set the cgroup slice of the service so that kube reserved takes effect
+{% if kube_reserved is defined and kube_reserved|bool %}
+Slice={{ kube_reserved_cgroups_for_service_slice }}
+{% endif %}
 
 [Install]
 WantedBy=multi-user.target

roles/container-engine/cri-dockerd/templates/cri-dockerd.service.j2

@@ -35,6 +35,10 @@ LimitCORE=infinity
 TasksMax=infinity
 Delegate=yes
 KillMode=process
+# Set the cgroup slice of the service so that kube reserved takes effect
+{% if kube_reserved is defined and kube_reserved|bool %}
+Slice={{ kube_reserved_cgroups_for_service_slice }}
+{% endif %}
 
 [Install]
 WantedBy=multi-user.target

roles/container-engine/cri-o/templates/crio.conf.j2

@@ -113,8 +113,12 @@ conmon = "{{ crio_conmon }}"
 {% if crio_cgroup_manager == "cgroupfs" %}
 conmon_cgroup = "pod"
 {% else %}
+{% if kube_reserved is defined and kube_reserved|bool %}
+conmon_cgroup = "{{ kube_reserved_cgroups_for_service_slice }}
+{% else %}
 conmon_cgroup = "system.slice"
 {% endif %}
+{% endif %}
 
 # Environment variable list for the conmon process, used for passing necessary
 # environment variables to conmon or the runtime.

roles/container-engine/docker/templates/docker.service.j2

@@ -42,6 +42,10 @@ TimeoutStartSec=1min
 Restart=on-failure
 StartLimitBurst=3
 StartLimitInterval=60s
+# Set the cgroup slice of the service so that kube reserved takes effect
+{% if kube_reserved is defined and kube_reserved|bool %}
+Slice={{ kube_reserved_cgroups_for_service_slice }}
+{% endif %}
 
 [Install]
 WantedBy=multi-user.target