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

Now with a simple Apprise integration!

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

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🔔 Changelog

• v0.4.0: Reworked selfupdate (auto git/curl/wget), general syntax cleanup, added -v for version.
• v0.3.8: Fixed --env-file logic to work with multiple env-files.
• v0.3.7: Added support for labels, added the -f option (force restart stack).
• v0.3.6: Added pushbullet template.
• v0.3.5: Added a simple progress bar for the registry checkup.
• v0.3.4: Added ntfy.sh template and error message on registry fail.
• 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.

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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.
-f     Force stack restart after update. Caution: restarts once for every updated container within stack.
-h     Print this Help.
-i     Inform - send a preconfigured notification.
-l     Only update if label is set. See readme.
-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).
-v     Prints current version.

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
  • Read the QuickStart
• ntfy.sh - HTTP-based pub-sub notifications.
• Pushbullet - connecting different devices with cross-platform features.

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

🔖 Labels

Optionally add labels to compose-files. Currently these are the usable labels:

    labels:
      mag37.dockcheck.restart-stack: true
      mag37.dockcheck.update: true

• mag37.dockcheck.restart-stack: true works instead of the -f option, forcing stop+restart on the whole compose-stack (Caution: Will restart on every updated container within stack).
• mag37.dockcheck.update: true will when used with the -l option only update containers with this label and skip the rest. Will still list updates as usual.

🎢 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).

👐 Function to auth with docker hub before running

Example - Change names, paths, and remove cat+password flag if you rather get prompted:

function dchk {
  cat ~/pwd.txt | docker login --username YourUser --password-stdin
  ~/dockcheck.sh "$@"
}

🔨 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.

⚠️ -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.

📜 License

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

💾 The story behind it. 1 year in retrospect.

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Special Thanks

• 🦬 t0rnis
• 🐆 Palleri