Problem
While upgrading a docker app a new container is downloaded. You might end up in a situation where the docker pull displays a message that there is no space left on device
failed to register layer: ApplyLayer exit status 1 stdout: stderr: open /tmp/APP/PATH/TO/SOME/FILE: no space left on device
or
7722 docker 19-04-09 14:11:42 [ INFO]: failed to register layer: mkdir /var/lib/docker/overlay/\<GUID\>/tmproot\<ID\>/usr/lib/node_modules/npm/node_modules/flush-write-stream: no space left on device
7722 docker 19-04-09 14:11:42 [ ERROR]: Command docker pull docker.software-univention.de/APP:x.y.z-ucs.n failed with: x.y.z-ucs.n: Pulling from \<APP\>
Investigation
Because the failed docker pull has saved several files and probably Megabytes or even Gigabytes it’s a good idea to clean up first. In order to do so investigate the docker environment. The following commands display the used disk space, the used space that was freed by that command and a list of all image which are present
root@ucs:~# docker system df
root@ucs:~# docker system prune
root@ucs:~# docker image ls -a
When you investigate the free space you might realize there is plenty or at least enough free space left.
root@ucs:~# df -h
Dateisystem Größe Benutzt Verf. Verw% Eingehängt auf
udev 10M 0 10M 0% /dev
tmpfs 401M 18M 384M 5% /run
tmpfs 1003M 0 1003M 0% /dev/shm
tmpfs 5,0M 0 5,0M 0% /run/lock
tmpfs 1003M 0 1003M 0% /sys/fs/cgroup
/dev/sda1 227M 108M 104M 51% /boot
/dev/mapper/vg_ucs-var 39G 17G 20G 46% /
overlay 39G 17G 20G 46% /var/lib/docker/overlay/\<GUID\>/merged
shm 64M 0 64M 0% /var/lib/docker/containers/\<GUID\>/shm
tmpfs 201M 0 201M 0% /run/user/0
Solution
If there is not enough free space you have to enlarge your partition; see this article on how to do so.
Bluespice
There was a special case with that app, see here