Updater only automatically deletes orphaned images, such as the ones that lost their tag because a newer image was downloaded for that tag. It doesn't auto delete non orphaned images even if they are not attached to a container.
https://github.com/linuxserver/li…ver.updater#L22
The prune button in the addon settings however does remove all images not attached to a container, but that is a manual operation, not automated.
https://github.com/linuxserver/li…settings.xml#L6
In other words, updater's cron operation uses "docker image prune -f" whereas the manual button uses "docker image prune -af" with the "a" being the critical flag.
It's interesting to know what the scripts actually do. Thanks. I thought the update did something else, like download the images, but I see it's empty.
In case it helps anyone, to avoid using watchtower with more containers and take advantage of existing scripts I have used this script which simply downloads the new images for the containers in use. So when updating, whether from Portainer or elsewhere, you can clearly see the containers with outdated images and it deploys much faster.
This is compatible with the prune script, as it doesn't delete tagged images. Only the orphaned ones that will be generated when actually deploying containers with the new image.
#!/bin/sh
# To add to cron copy this file in /storage/.kodi/userdata/addon_data/docker.linuxserver.updater/update.sh
# chmod +x /storage/.kodi/userdata/addon_data/docker.linuxserver.updater/update.sh
# Get the list of active containers
containers=$(docker ps --format "{{.Names}}")
for container in $containers; do
# Get the image used by the container
image=$(docker inspect --format '{{.Config.Image}}' "$container")
echo "Pulling latest image for container: $container (Image: $image)"
docker pull "$image"
done