![Watchtower {shmolf}]()
Watchtower {shmolf}
Container
A container-based solution for automating Docker container base image updates
Image details
Pulls: 8.2B
Architecture: amd64, arm64, arm/v6, 386, arm, arm64/v8
Image size: 5 MB
Latest: 1.7.1
User: containrrr
Created: Apr 03, 2019
Updated: 2 years ago
Status: active
Source details
Repo: containrrr/watchtower
Stars: 24.7k
Forks: 1k
Language: Go
License: Apache-2.0
Latest: v1.7.1 · 2 years ago
Updated: 8 months ago
Website: containrrr.dev/watchtower/
Status: archived
Configuration
TypeContainerlinuxcontainrrr/watchtower9001/tcp/var/run/docker.sock : /var/run/docker.sockalwaysTemplate by shmolf
Notes
Standalone Install
Select an install method, to see config/commands for deploying Watchtower {shmolf}
Install on Portainer
Import all app templates into your Portainer instance, for easy 1-click deploys
- Ensure both Docker and Portainer are installed, and up-to-date
- Log into your Portainer web UI
- Under Settings → App Templates, paste the below URL
- Head to Home → App Templates, and the list of apps will show up
- Select Watchtower {shmolf}, fill in any config options, and hit Deploy
Template Import URL
https://raw.githubusercontent.com/Lissy93/portainer-templates/main/templates.json
Show Me
More install options in our documentation, or see containrrr/watchtower for app-specific guidance.
Watchtower
A process for automating Docker container base image updates.
<img alt="Circle CI" src="https://circleci.com/gh/containrrr/watchtower.svg?style=shield" /><img alt="GoDoc" src="https://godoc.org/github.com/containrrr/watchtower?status.svg" /><img alt="Microbadger" src="https://images.microbadger.com/badges/image/containrrr/watchtower.svg" /><img alt="Go Report Card" src="https://goreportcard.com/badge/github.com/containrrr/watchtower" /><img alt="latest version" src="https://img.shields.io/github/tag/containrrr/watchtower.svg" /><img alt="Apache-2.0 License" src="https://img.shields.io/github/license/containrrr/watchtower.svg" /><img alt="Codacy Badge" src="https://api.codacy.com/project/badge/Grade/3a4d0fcfd26d45b09b1d7ea3c8c13744"/><img alt="Codacy Badge" src="https://api.codacy.com/project/badge/Coverage/3a4d0fcfd26d45b09b1d7ea3c8c13744" /><img alt="Join the chat at https://gitter.im/containrrr/watchtower" src="https://badges.gitter.im/containrrr/watchtower.svg" /><img alt="All Contributors" src="https://img.shields.io/badge/all_contributors-30-orange.svg?style=flat-square" /><img alt="Pulls from DockerHub" src="https://img.shields.io/docker/pulls/containrrr/watchtower.svg?style=flat-square" />
⚠️ Help needed
As I @simskij currently am the sole maintainer of watchtower, i'm finding it a bit hard to keep up with all issues and pull requests. Interested in helping out with triage, troubleshooting and issue handling? Let me know on gitter!
Quick Start
With watchtower you can update the running version of your containerized app simply by pushing a new image to the Docker Hub or your own image registry. Watchtower will pull down your new image, gracefully shut down your existing container and restart it with the same options that were used when it was deployed initially. Run the watchtower container with the following command:$ docker run -d \
--name watchtower \
-v /var/run/docker.sock:/var/run/docker.sock \
containrrr/watchtowerDocumentation
The full documentation is available at https://containrrr.github.io/watchtower.Contributors
Thanks goes to these wonderful people (emoji key):This project follows the all-contributors specification. Contributions of any kind welcome!
Serve Watchtower {shmolf} on your own domain behind Caddy, Nginx or Traefik. Fill in your domain and copy the result. It's a starting point, some apps need their own base URL or extra headers set too.
Proxying watchtower-shmolf.example.com to http://watchtower:9001
Add this to your Caddyfile
watchtower-shmolf.example.com {
reverse_proxy http://watchtower:9001
}Check the logs first
Nine times out of ten the logs tell you exactly what went wrong.
- In Portainer, go to Containers, click the container, then Logs. Or run
docker logs watchtower - Exit codes help too:
137means killed, usually out of memory.126or127means the command inside the image is broken.
Published on a random port
This template exposes 9001/tcp without setting a host port,
so Docker picks a random free one on every deploy.
- Find it in the Ports column of Portainer's container list, or with
docker port watchtower
Can't reach the Docker socket
watchtower talks to Docker through /var/run/docker.sock. If the logs show
"permission denied while trying to connect to the Docker daemon socket", the app's user can't access it.
- Check the socket exists on the host:
ls -l /var/run/docker.sock - Run the container as root, or add the docker group's id to the container with
group_add.
Image won't pull
Test the pull directly on the host: docker pull containrrr/watchtower
- "manifest unknown" means the tag no longer exists. This template uses
latest, so try pinning a specific version instead. - "toomanyrequests" is the Docker Hub rate limit. Log in with
docker loginto raise it. - "no space left on device" means a full disk. Reclaim space with
docker system prune
"exec format error"
This means the image was built for a different CPU architecture than your server.
- This image supports:
amd64, arm64, arm/v6, 386, arm, arm64/v8 - Check yours with
uname -m: x86_64 is amd64, aarch64 is arm64. Raspberry Pi and other ARM boards are the usual culprits.
Container keeps restarting
The always restart policy relaunches the app after every crash, so the real error can scroll past.
- Check the logs right after a restart, the last few lines before it died are the useful ones.
- Get the exit code with
docker inspect watchtower --format '{{.State.ExitCode}}' - Still stuck? Redeploy once with the restart policy set to
noso the failure stays visible.
Upstream project is archived
The developers have archived containrrr/watchtower, so bugs and security issues won't be fixed.
- It'll keep working for now, but consider the similar apps below for a maintained alternative.
Raise an issue
Found something which isn't working as it should? Here's how to report it.
- Bug within the app: Open an issue on containrrr/watchtower
- Template not working: Open an issue on shmolf/portainer-templates
- This website not working: Open an issue on lissy93/portainer-templates
A single container
Watchtower {shmolf} runs as one container, the simplest kind of app here. Just the one image to pull and nothing else wired up alongside it.
The app image
An image is the app packed up ready to go, everything Watchtower {shmolf} needs bundled into one download. This template pulls containrrr/watchtower, which Docker fetches once (about 5 MB) and then starts your own copy from.
Where the image comes from
Docker pulls its images from registries, public libraries of ready-built apps. Watchtower {shmolf}'s comes from Docker Hub, published by containrrr.
Version tags
The bit after the colon in the image name is the version tag. Here it's latest, which always points at the newest build, so a redeploy can bump you to a newer release without you asking. Newest right now is 1.7.1. Pin a specific tag if you would rather stay on one version.
Which machines it runs on
Every image is built for particular CPU types. This one ships for amd64, arm64, arm/v6, 386, arm, arm64/v8, so it runs on both regular x86 servers and ARM boards like a Raspberry Pi.
Ports
A port is the door the app answers on. Here the app exposes a port but leaves the host side blank, so Docker picks a free one for you. It opens:
9001, published on a random host port
Volumes
A volume is where Watchtower {shmolf} keeps its files so they survive an update or a restart. Without one, anything it saves would sit inside the container and vanish the moment it's recreated. This template mounts:
/var/run/docker.sockfrom/var/run/docker.sockon the host (a socket it talks to, not storage)
Restart policy
The restart policy here is always, so Docker brings Watchtower {shmolf} back up after a crash and again when the server reboots. Good for anything you want running around the clock. You can change this on the deploy screen. The choices are no (never restart), on-failure (only after a crash), unless-stopped (restart unless you stop it), and always (bring it back no matter what).
Networking
Nothing custom is set, so Watchtower {shmolf} sits on Docker's default bridge network: its own private space that reaches the outside world only through the ports it publishes.
Container name
Once it's deployed, Portainer names the container watchtower. That's what you'll spot in the containers list and use in commands like docker logs watchtower.
Platform
The platform is linux, the kind of system the container is built to run on. Docker and Portainer handle this on a normal Linux server.
Open source license
Watchtower {shmolf} is open source, released under the Apache-2.0 license. In plain terms the code is out in the open, so you're free to run it and change it to fit what you need.
Portainer app templates
Zooming out, this whole page comes from a Portainer app template: a short recipe telling Portainer how to set Watchtower {shmolf} up. Add the template list to Portainer once, then deploying Watchtower {shmolf} is a click rather than a wall of config.