ContainerCleaner

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📖 About

ContainerCleaner is a port of my CERN project, PodmanCleaner. It runs automatically via cron or systemd, and can:

• Optionally pull a git repository
• Pull the latest container images
• Recreate Docker Compose or Docker Swarm containers
• Remove unused images

This helps:

• Keep storage use to a minimum on the host
• Ensure all services are up-to-date
• Prevent hung processes or stale containers

Currently supports Docker Compose and Docker Swarm only. Future support for Podman, Kubernetes, or standalone Docker may be added based on demand.

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⚙️ How to Install

🐧 These instructions assume a Debian-based distro (e.g., Ubuntu, Mint, Pop!_OS).

1. Install required system packages:

sudo apt update && sudo apt install -y git curl python3 python3-pip

2. Install required Python modules:

Via APT:

sudo apt install -y python3-colorama python3-git python3-docker python3-requests python3-yaml

Or via pip:

pip install colorama gitpython docker requests pyyaml

3. Clone and enter the repository:

cd /usr/share/ && sudo git clone https://github.com/jamess60/containercleaner.git && cd containercleaner

4. Configure containercleaner (Refer to section below for more help):

sudo nano /usr/share/containercleaner/conf/config.ini

sudo nano /usr/share/containercleaner/src/functions/ntfy.py

5. Manually test the script:

python3 /usr/share/containercleaner/src/ContainerCleaner.py

6. Enable the systemd timer:

sudo cp /usr/share/containercleaner/conf/systemd/* /etc/systemd/system/ && sudo systemctl daemon-reload && sudo systemctl enable containercleaner.timer

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📝 Additional Install Notes:

• If you prefer cron, an example is provided in conf/ContainerCleaner.cron.
• To change the timer frequency, edit conf/systemd/containercleaner.timer before copying it.
• Running both docker_compose and docker_swarm modes in the same instance is not supported. Use separate instances if needed.
• If you are running containercleaner in a none defualt location (anywhere other than /usr/share/containercleaner), you will need to modify line 10 in src/functions/ntfy.py and line 29 in ContainerCleaner.py to reflect the new location of the config file.

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🧾 Configuration Keys Explained

conf/config.ini

Section	Key	Description	Value(s) / Example	Notes
MAIN	CONTAINER_ENGINE	Choose which container engine you are running	docker_compose OR docker_swarm
DOCKER_COMPOSE	COMPOSE_FILES	Specify the path(s) to the compose file(s) you wish to automatically update	/root/containers/compose_files/webserver.yml	Can be left blank if not using docker_compose for CONTAINER_ENGINE
DOCKER_SWARM	SWARM_FILES	Specify the path(s) to the swarm file(s) you wish to automatically update	/root/containers/swarm_files/webserver.yml	Can be left blank if not using docker_swarm for CONTAINER_ENGINE
GIT	GIT_ENABLED	Disable or Enable pulling git repos before compose/swarm files are updated.	True OR False
GIT	GIT_REPO_PATHS	Paths to Dirs which are git managed	/root/containers	Can be left blank if Git is disabled
NTFY	NTFY_ENABLED	Disable or Enable sending notifications to an Ntfy server	True OR False
NTFY	NTFY_HOST	Ntfy server URL	https://ntfy.yourdomain.co.uk	Can be left blank if Ntfy is disabled
NTFY	NTFY_TOPIC	Ntfy server topic	ContainerCleaner	Can be left blank if Ntfy is disabled

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❓ FAQ

1. The script says "This script may KILL and DELETE containers without confirmation" – is that true?
👉 It only kills/recreates containers the same way docker compose up -d or docker stack deploy would. No containers are stopped unless they need to be updated. This is the only way to rebase a container on to a new image, and alternative tools (such as Watchtower) would do the same.

2. Why not just use a one-liner bash script?
👉 That would limit future features like ntfy integration, config parsing, and Swarm support.

3. Isn't this basically Watchtower with extra steps?
👉 Sort of — but Watchtower can be slow to recreate containers and doesn’t always clean up old images.
ContainerCleaner is a faster, more secure alternative that avoids using docker.sock directly.

4. I use Docker Swarm — where should I run this?
👉 Run it on one manager node only. Worker nodes can’t deploy stacks.
If you want redundancy, install it on two manager nodes, spacing their timers at least an hour apart.

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🌟 Feature Wishlist

• Dry run/simulation mode
• Full logging support
• Multi-repo & multi-file support
• Packaging as .deb, .rpm
• Explore ContainerCleaner as a container (although this would negate the no touching docker.sock benefit)
• Improved validation and sanity checks
• Alternative notification services (such as Discord/Telegram)

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