systemd: set start burst limits

Note that StartLimit* options were moved from "Service" to "Unit" in systemd 229
(https://github.com/systemd/systemd/commit/6bf0f408e4833152197fb38fb10a9989c89f3a59)
both the old, and new location are accepted by systemd 229 and up, so using the old location
to make them work for either version of systemd.

StartLimitInterval was renamed to StartLimitIntervalSec in systemd 230
(https://github.com/systemd/systemd/commit/f0367da7d1a61ad698a55d17b5c28ddce0dc265a)
both the old, and new name are accepted by systemd 230 and up, so using the old name to make
this option work for either version of systemd.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

contrib/init/systemd/docker.service

@@ -18,6 +18,17 @@ ExecStopPost=/usr/bin/dockerd post-stop
 TimeoutSec=0
 RestartSec=2
 Restart=always
+
+# Note that StartLimit* options were moved from "Service" to "Unit" in systemd 229.
+# Both the old, and new location are accepted by systemd 229 and up, so using the old location
+# to make them work for either version of systemd.
+StartLimitBurst=3
+
+# Note that StartLimitInterval was renamed to StartLimitIntervalSec in systemd 230.
+# Both the old, and new name are accepted by systemd 230 and up, so using the old name to make
+# this option work for either version of systemd.
+StartLimitInterval=60s
+
 # On RPM Based distributions PATH isn't defined so we define it here
 # /opt/containerd/bin is in front so dockerd grabs the correct runc binary
 Environment="PATH=/opt/containerd/bin:/sbin:/usr/bin:/usr/local/bin:$PATH"