This container runs OpenNTPD on Alpine Linux. More about NTP can be found at:
Download the docker-compose.yml from this repository and place it in a clean directory.
Running Docker-ntp as a service in the background:
$> docker-compose up -d
Manually pull the image from Docker hub (for example, to update to a newer version):
$> docker-compose pull
Build the image locally (useful to test changes to the Dockerfile):
$> docker-compose build
Check and edit the content of docker-compose.yml to load your own ntpd.conf config file.
Pull and run -- it's this simple.
# Pull from docker hub
$> docker pull nicoinn/docker-ntp
# Run docker-ntp
$> docker run --name=ntp \
--restart=always \
--detach=true \
--publish=123:123/udp \
--cap-add=SYS_RESOURCE \
--cap-add=SYS_TIME \
nicoinn/docker-ntp
Add
-v /path/to/folder/containing/my_config_file:/data
to the command above.
Note that this way, one can also save the NTP drift file accross container restarts by adding
driftfile /data/drift
into your ntpd.conf file.
From any machine that has ntpdate you can query your new NTP container with the follow
command:
$> ntpdate -q <DOCKER_HOST_IP>
Here is a sample output from my environment:
$> ntpdate -q 10.13.13.9
server 10.13.13.9, stratum 3, offset 0.010089, delay 0.02585
17 Sep 15:20:52 ntpdate[14186]: adjust time server 10.13.13.9 offset 0.010089 sec
If you see a message, like the following, it's likely the clock is not yet synchronized.
$> ntpdate -q 10.13.13.9
server 10.13.13.9, stratum 16, offset 0.005689, delay 0.02837
11 Dec 09:47:53 ntpdate[26030]: no server suitable for synchronization found
To see details on the ntpd status, you can check with the below command on your docker host:
$> docker exec docker-ntp ntpctl -s status
4/4 peers valid, clock synced, stratum 2