/etc/init/docker.conf It’s a script to start docker server daemon. Please the code below
description "Docker daemon"
start on (local-filesystems and net-device-up IFACE!=lo)
stop on runlevel [!2345]
limit nofile 524288 1048576
limit nproc 524288 1048576
respawn
kill timeout 20
pre-start script
#see also https://github.com/tianon/cgroupfs-mount/blob/master/cgroupfs-mount
if grep -v '^#' /etc/fstab | grep -q cgroup \
|| [ ! -e /proc/cgroups ] \
|| [ ! -d /sys/fs/cgroup ]; then
exit 0
fi
if ! mountpoint -q /sys/fs/cgroup; then
mount -t tmpfs -o uid=0,gid=0,mode=0755 cgroup /sys/fs/cgroup
fi
(
cd /sys/fs/cgroup
for sys in $(awk '!/^#/ { if ($4 == 1) print $1 }' /proc/cgroups); do
mkdir -p $sys
if ! mountpoint -q $sys; then
if ! mount -n -t cgroup -o $sys cgroup $sys; then
rmdir $sys || true
fi
fi
done
)
end script
script
#modify these in /etc/default/$UPSTART_JOB (/etc/default/docker)
DOCKER=/usr/bin/$UPSTART_JOB
DOCKER_OPTS=
if [ -f /etc/default/$UPSTART_JOB ]; then
. /etc/default/$UPSTART_JOB
fi
exec "$DOCKER" daemon $DOCKER_OPTS
end script
#Don't emit "started" event until docker.sock is ready.
#See https://github.com/docker/docker/issues/6647
post-start script
DOCKER_OPTS=
if [ -f /etc/default/$UPSTART_JOB ]; then
. /etc/default/$UPSTART_JOB
fi
if ! printf "%s" "$DOCKER_OPTS" | grep -qE -e '-H|--host'; then
while ! [ -e /var/run/docker.sock ]; do
initctl status $UPSTART_JOB | grep -qE "(stop|respawn)/" && exit 1
echo "Waiting for /var/run/docker.sock"
sleep 0.1
done
echo "/var/run/docker.sock is up"
fi
end script
</pre>
/etc/apt/sources.list.d/docker.list #It's defined docker package source
/etc/systemd/system/sockets.target.wants/docker.socket #docker conf for Systemd
/etc/systemd/system/multi-user.target.wants/docker.service #docker conf for Systemd
/etc/apparmor.d/cache/docker #component
/etc/apparmor.d/docker #component
/etc/default/docker #SysVinit configuration file
/etc/init.d/docker #It is included by /etc/init/docker.conf
/etc/bash_completion.d/docker #bash completion file for core docker commands
systemd详解