Merge pull request #20633 from crosbymichael/unit-file

Add "Delegate=yes" to docker's service file

contrib/init/systemd/docker.service

@@ -6,12 +6,17 @@ Requires=docker.socket
 
 [Service]
 Type=notify
+# the default is not to use systemd for cgroups because the delegate issues still
+# exists and systemd currently does not support the cgroup feature set required
+# for containers run by docker
 ExecStart=/usr/bin/docker daemon -H fd://
 MountFlags=slave
 LimitNOFILE=1048576
 LimitNPROC=1048576
 LimitCORE=infinity
 TimeoutStartSec=0
+# set delegate yes so that systemd does not reset the cgroups of docker containers
+Delegate=yes
 
 [Install]
 WantedBy=multi-user.target