A script checking updates for docker images without pulling
Then selectively auto-update containers.

With features like excluding specific containers, filter by name, auto-prune dangling images and more.

🔔 Changelog

• v0.3.3: Added Apprise template and the option -i inform - to send notifications.
• v0.3.2: Added a notify function to wrap a notify-script, currently DSM/Ssmtp + template script.
• v0.3.1: Addded option -m , monochrome mode - no printf color codes.
• v0.3.0: Added option -d N, age (days) new images have to be before being pulled and updated.
• v0.2.6: regctl check / download logic changed. Now using the scripts directory as primary location.
• v0.2.5: Added a new option -s to include stopped containers in the check for updates.

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Dependencies

• Running docker (duh) and compose, either standalone or plugin.
• regclient/regctl (Licensed under Apache-2.0 License)
  • User will be prompted to download regctl if not in PATH or PWD.
  • regctl requires amd64/arm64 - see workaround if other architecture is used.

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dockcheck.sh

$ ./dockcheck.sh -h
 Syntax:     dockcheck.sh [OPTION] [part of name to filter]
 Example:    dockcheck.sh -y -d 10 -e nextcloud,heimdall
 
 Options:
 -a|y   Automatic updates, without interaction.
 -d N   Only update to new images that are N+ days old. Lists too recent with +prefix and age. 2xSlower.
 -e X   Exclude containers, separated by comma.
 -h     Print this Help.
 -i     Inform - send a preconfigured notification.
 -m     Monochrome mode, no printf color codes.
 -n     No updates, only checking availability.
 -p     Auto-Prune dangling images after update.
 -r     Allow updating images for docker run, wont update the container.
 -s     Include stopped containers in the check. (Logic: docker ps -a)

Basic example:

$ ./dockcheck.sh
. . .
Containers on latest version:
glances
homer

Containers with updates available:
1) adguardhome
2) syncthing
3) whoogle-search

Choose what containers to update:
Enter number(s) separated by comma, [a] for all - [q] to quit:

Then it proceedes to run pull and up -d on every container with updates.
After the updates are complete, you'll get prompted if you'd like to prune dangling images.

📢 Notifications

Trigger with the -i flag.
Run it scheduled with -ni to only get notified when there's updates available!

Use a notify_X.sh template file, copy it to notify.sh, modify it to your needs!
Current templates:

• Synology DSM
• Email with sSMTP
• Apprise (with it's multitude of notifications)
  • both native caronc/apprise and the standalone linuxserver/docker-apprise-api

Further additions are welcome - suggestions or PR!
Initiated and first contributed by yoyoma2.

⚠️ -r flag disclaimer and warning

Wont auto-update the containers, only their images. (compose is recommended)
docker run dont support using new images just by restarting a container.
Containers need to be manually stopped, removed and created again to run on the new image.

🔨 Known issues

• No detailed error feedback (just skip + list what's skipped).
• Not respecting --profile options when re-creating the container.
• Not working well with containers created by Portainer.

🎢 Workaround for non amd64 / arm64

regctl provides binaries for amd64/arm64, to use on other architecture you could try this workaround. Run regctl in a container wrapped in a shell script. Copied from regclient/docs/install.md:

cat >regctl <<EOF
#!/bin/sh
opts=""
case "\$*" in
  "registry login"*) opts="-t";;
esac
docker container run \$opts -i --rm --net host \\
  -u "\$(id -u):\$(id -g)" -e HOME -v \$HOME:\$HOME \\
  -v /etc/docker/certs.d:/etc/docker/certs.d:ro \\
  ghcr.io/regclient/regctl:latest "\$@"
EOF
chmod 755 regctl

Test it with ./regctl --help and then either add the file to the same path as dockcheck.sh or in your path (eg. ~/.local/bin/regctl).

dc_brief.sh

Just a brief, slimmed down version of the script to only print what containers got updates, no updates or errors.

License

dockcheck is created and released under the GNU GPL v3.0 license.

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Check out a spinoff project: Palleri/DCW for a WebUI-front with exporters and notifications.

Special Thanks

• 🦬 t0rnis
• 🐆 Palleri