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Watchtower – Automated Updates in Container Manager on a Synology NAS

Last updated on 14 November 2024

Important or Recent Updates
Historic UpdatesDate
New guide update for DSM7.2 and Container Manager30/04/2023
Added labels to GlueTUN container guide so updated information in this one to coincide06/05/2023
Added a 3rd option to just exclude specific containers via a label.23/11/2023
Historic Updates


What is Watchtower?

Watchtower monitors and automatically updates your containers to the latest versions for you, it is useful as it is not limited to which Docker repositories it can pull from. The Container Manager UI can only notify you of updates for container images from Docker Hub, not the popular GitHub.

Let’s Begin

We will be setting up Watchtower using the Project functionality in Container Manager. This uses a compose file to tell Docker how to set up the container and also define some preferences.

Folder Setup

Let’s start by getting a folder set up for the container to use. Open up File Station create the following.

Folders
/docker/projects/watchtower-compose


Container Manager

Next we are going to set up a ‘Project’ in Container Manager. Open up Container Manager and click on Project then on the right-hand side click ‘Create’.

In the next screen we will set up our General Settings, enter the following:

SectionSetting
Project Name:watchtower
Path:/docker/projects/watchtower-compose
Source:Create docker-compose.yml

We have a couple of different composes available below, the first one is configured to update all running containers at 2am daily.

YAML
services:
  watchtower:
    image: containrrr/watchtower:latest
    container_name: watchtower
    environment:
      - TZ=YOURTIMEZONE
      - WATCHTOWER_CLEANUP=true
      - WATCHTOWER_INCLUDE_STOPPED=true
      - WATCHTOWER_REVIVE_STOPPED=false
      - WATCHTOWER_SCHEDULE=0 0 2 * * *
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    restart: unless-stopped

As an addition to the method above you can exclude specific containers from updates by adding this line to their yaml (compose) details. This is likely faster than using method 2

YAML
    labels:
      - com.centurylinklabs.watchtower.enable=false

The second has an added section where you can specify the names of the containers you would like to update (use the exact name of the container as per the Synology UI)

YAML
services:
  watchtower:
    image: containrrr/watchtower:latest
    container_name: watchtower
    environment:
      - TZ=YOURTIMEZONE
      - WATCHTOWER_CLEANUP=true
      - WATCHTOWER_INCLUDE_STOPPED=true
      - WATCHTOWER_REVIVE_STOPPED=false
      - WATCHTOWER_SCHEDULE=0 0 2 * * *
    command: # add or remove the below as required
      - overseerr
      - plex
      - prowlarr
      - radarr
      - sonarr
      - tautulli
      - watchtower
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    restart: unless-stopped

You can copy and paste the one you wish to use into the blank section in Container Manager.

Environment Variables

We need to make some changes in order for watchtower to know what time it is where you are and what we want it to do. You can amend these in the compose based on your preferences.

VariableValueWhat it does
TZEurope/LondonChange this to your own timezone
WATCHTOWER_CLEANUPtrue or falseWe want to clean up the old docker images, if you don’t turn this on over the course of a few months you will find that the images start to eat a lot of space, and they are not even being used. (true or false)
WATCHTOWER_INCLUDE_STOPPEDtrue or falseDo you want to update any stopped containers, the container will stay stopped after being updated (true or false)
WATCHTOWER_REVIVE_STOPPEDtrue or falseIf a stopped container is updated do you want Watchtower to start it up? (true or false)
WATCHTOWER_SCHEDULE0 0 2 * * *Rather than setting the number of seconds to wait between checks you can set a schedule. The default I use for the guide is 2am every day, you can work out your own schedule using a cron schedule generator.

Click ‘Next’

You do not need to enable anything on the ‘Web portal settings’ screen click ‘Next’ again

On the final screen click Done which will begin the download of the container images and once downloaded they will be launched!

The image will now be downloaded and extracted. You should see ‘Code 0’ when it has finished.

You will now see your watchtower project running it should have a green status on the left-hand side.

You can now just leave Watchtower running you will never need to manually update your containers again.

FAQ

I keep getting X container has stopped unexpectedly errors!
DSM does not know or understand that Watchtower is issuing commands in the background. So it makes the assumption that a container was stopped unexpectedly, but we know it was Watchtower doing an update.

Do I need to update Watchtower itself?
Nope it updates itself – quite clever really 🙂



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Published inDockerSynologyUpdating Containers 7.2

39 Comments

  1. Benji Benji

    Hi doctor, I noticed this docker-compose doesn’t have the “network_mode: synobridge” like usual, is that intended? I guess it doesn’t really matter for watchtower?

    • Dr_Frankenstein Dr_Frankenstein

      Hey Benji – Yeah no need for this to be on a specific bridge, we only put items that need to talk to one another on the same bridge.

  2. Ryan Ryan

    if we were following option 1 in this post, did we have to add the extra line to prevent watchtower from being updated, or was that option?

    • Dr_Frankenstein Dr_Frankenstein

      That second line is for you to add to specific containers you don’t want watchtower to update, for example I layer it into GlueTUN guides to avoid issues with it being updated automatically.

  3. Logix Logix

    Hi,

    Hoping to get some assistance with watchtower and getting GlueTun to update.

    I followed the guide above a few days ago to set up Watchtower (I only used the first set of docket compose code in the guide) and noticed that only my deluge image has been updated, the gluetun image is still running an older version (which I followed your guide one as well; though it was quite a while back).

    Not sure if I’ve missed a step somewhere.

    Any help would be greatly appreciated.

    • Dr_Frankenstein Dr_Frankenstein

      Hey – So you will notice there is a label on the GlueTUN container which excludes it from auto updates – this is due to the overall project will become unhealthy as the attached containers won’t be able to re-attach until the whole project is stopped and started. So you need to do a manual update.

      • Logix Logix

        Thanks for the explanation.

        For a moment there, i thought i missed something in the code.

  4. Joseki Joseki

    Hello, just to confirm, will this also update containers that are part of a project?

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