ceph/systemd/ceph-mgr@.service

[Unit]
Description=Ceph cluster manager daemon
After=network-online.target local-fs.target time-sync.target ceph-mon@%i.service
Wants=network-online.target local-fs.target time-sync.target
PartOf=ceph-mgr.target ceph-mon@%i.service

[Service]
LimitNOFILE=1048576
LimitNPROC=1048576
EnvironmentFile=-/etc/sysconfig/ceph
Environment=CLUSTER=ceph

# This ExecStartPre business is a hack to inject a key for the mgr daemon,
# using whatever key already exists on the mon on this node to gain sufficient
# permissions to create the mgr key.  Failure is ignored at every step (the
# '-' prefix) in case someone has already used some other trick to set
# everything up manually.
# `sh -c "exec ..."` is required, since different Linux ditributives have different rules on absolute paths of that executables.
# systemd requires to use absoulte paths.
ExecStartPre=-/bin/sh -c "exec mkdir -p /var/lib/ceph/mgr/${CLUSTER}-%i"
ExecStartPre=-/bin/sh -c "[ -f /var/lib/ceph/mgr/${CLUSTER}-%i/keyring ] || /usr/bin/ceph-authtool --create-keyring --gen-key --name=mgr.%i /var/lib/ceph/mgr/${CLUSTER}-%i/keyring"
ExecStartPre=-/bin/sh -c "exec chown -R ceph.ceph /var/lib/ceph/mgr/${CLUSTER}-%i"
ExecStartPre=-/usr/bin/ceph -i /var/lib/ceph/mgr/${CLUSTER}-%i/keyring auth add mgr.%i mon 'allow profile mgr' --keyring=/var/lib/ceph/mon/${CLUSTER}-%i/keyring --name=mon.

ExecStart=/usr/bin/ceph-mgr -f --cluster ${CLUSTER} --id %i --setuser ceph --setgroup ceph
ExecReload=/bin/kill -HUP $MAINPID
Restart=on-failure
StartLimitInterval=30min
StartLimitBurst=3

[Install]
WantedBy=ceph-mgr.target