Clearing/Deleting Docker Logs
On our docker implementation on GCE, we are running out of space on the root file system.
Since images themselves are stored on a separate 1TB volume, the images themselves shouldn't be the problem.
One candidate are the centralized logfiles that Docker itself stores (a json file somewhere?), does anyone know where those files/file are/is located, and how we can logrotate/truncate them?
First, I'm using docker 1.1.2 for both client and server, this answer may be obsolete for newer versions of docker as docker evolve quickly.
Location of the file
Find your docker directory. On systems that use apt/debian style system, the package installed by the docker repository https://get.docker.com/ubuntu use /var/lib/docker. Chances are that directory is in the same place on other systems (can't confirm).
under containers/**CONTAINER_ID** you'll find infos about the container.
In the file **CONTAINER_ID**-json.log in that folder, you'll find a file with all the logs for that container. It may look like a json file, it's not. It's a flow a json structures, one per line, each containing one log line (each line ends by a } and the next one starts with a {, thus it's not a valid json as a whole).
Example location:
- /var/lib/docker/containers/05b6053c41a2130afd6fc3b158bda4e605b6053c41a2130afd6fc3b158bda4e6/05b6053c41a2130afd6fc3b158bda4e605b6053c41a2130afd6fc3b158bda4e6-json.log
Editing/Altering that file
I suggest you to use that path to see wether or not it's the reason why you're running out of space, but not to log rotate them.
I would rather make sure the container doesn't log too much lines (by using a CMD in the dockerfile that either redirect the output of you process to a file in a volume or to /dev/null - with logs enabled with configuration - and I would then logrotate the log files with another container)
Here a simple one-liner to clean container log file:
echo "" > $(docker inspect --format='{{.LogPath}}' <container_name_or_id>)
if you run sudo lsof | grep '(deleted)', you might find that there are a lot of deleted container log files left open by docker
docker 17511 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 2879 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 6191 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 8713 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 8726 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 9907 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 9918 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 11093 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 11096 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 11110 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 11885 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 11890 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 11973 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 11976 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 11983 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 13105 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 16737 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 17139 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 17516 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 17517 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 17518 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 17519 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 17520 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 17525 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 17574 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 17584 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 17586 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 17637 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 17643 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 17644 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 17659 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 17666 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 17669 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 17680 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 17884 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 17895 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 21126 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 21474 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 21475 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 21519 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 21721 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 23829 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 23830 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 23833 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 24196 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 24197 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 26821 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 28597 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 28608 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 30305 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 30308 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 30594 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
docker 17511 30595 root 25r REG 202,1 105 456624 /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
These are logs that belong to a deleted container. One way to have these closed is by restarting the docker daemon itself. This is not always feasible.
Another way to free this space is to find the relevant file descriptor and to truncate it:
ls -lh /proc/17511/fd/ | grep e49d81fc
lr-x------ 1 root root 64 Sep 8 08:06 25 -> /var/lib/docker/containers/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc/39ba30ffc0e218ee830576570222284a93ebb458eadf46933d2dd7afe49d81fc-json.log (deleted)
Where 17511 is the pid of docker and e49d81fc is part of the offending logfilename / container id. Here, the fd is /proc/17511/fd/25, so we truncate it:
cat /dev/null > /proc/17511/fd/25
I am using Docker version 1.13.0, build 49bf474
If you are using the default logging format json-file, then you can specify the option to rotate your logs.
You can set up the docker daemon to do that or set it up per container.
For instance, log file size of 2 MB and maximum of 5 logfiles:
Docker daemon: Create file /etc/docker/daemon.json:
{
"log-driver": "json-file",
"log-opts": {
"max-size": "2m",
"max-file": "5",
}
}
Docker run:
docker run -it --log-driver json-file --log-opt max-size=2m,max-file=5 alpine ash
For details see logging and dockerd configuration