Introduction:

Today we are going to be installing Watchtower using a watchtower docker compose stack in Portainer. This is episode 19 in our Raspberry Pi 4 Series.

Watchtower enables you to monitor all your docker containers for updates. We will be configuring it to notify you of any new updates via your SMTP server to an email address of your choice.

https://www.youtube.com/watch?v=_Ji4_L7I3Mw&t=242s

Alternatively, you can also set Watchtower to just auto-update your containers. Although this is not advised on a Live server. If anything goes wrong with any of the updates, it can make troubleshooting the problem harder if multiple containers have been automatically updated.

Prerequisites:

• A Raspberry Pi with Raspberry Pi OS installed. We recommend using an SSD.
• Secured Raspberry Pi.
• Openmediavault, Docker and Portainer Installed.
• You will need to have an account with an SMTP server provider and know your account and server details. If you would like to use Gmail's free SMTP server watch today's video episode above or on Youtube.

Step 1 - Create the Watchtower Container Using Portainer & A Docker Compose Stack

Navigate to your Portainer dashboard and log in.

From the left hand menu click on "Stacks".

Now in the Stacks dashboard click on "Add a stack".

In the "Name" field enter "watchtower"

Now Copy and paste the following docker-compose data into the "Web editor" field.

Watchtower Docker Compose Stack

version: '2.1'
services:
    watchtower:
        image: containrrr/watchtower
        container_name: watchtower
        volumes:
            - /var/run/docker.sock:/var/run/docker.sock
        environment:
            - TZ=Europe/London
            - WATCHTOWER_MONITOR_ONLY=true
            - WATCHTOWER_CLEANUP=true
            - WATCHTOWER_SCHEDULE= 0 0 04 ? * FRI #At 04:00 AM, only on Friday Change to suit
            - WATCHTOWER_NOTIFICATIONS=email
            - WATCHTOWER_NOTIFICATION_EMAIL_FROM=FromEmail
            - WATCHTOWER_NOTIFICATION_EMAIL_TO=ToEmail
            - WATCHTOWER_NOTIFICATION_EMAIL_SERVER=smtp.server.com
            - WATCHTOWER_NOTIFICATION_EMAIL_SERVER_PASSWORD=password
            - WATCHTOWER_NOTIFICATION_EMAIL_SUBJECTTAG=Watchtower Alert - Container Updates
            - WATCHTOWER_NOTIFICATION_EMAIL_SERVER_USER=FromEmail
            - WATCHTOWER_NOTIFICATION_EMAIL_SERVER_PORT=587
        restart: unless-stopped

Edit and replace the fields after the "="with your "SMTP server data".

NOTICE: The WATCHTOWER_NOTIFICATION_EMAIL_SERVER_PASSWORD will not work correctly if you use special characters in your SMTP account password.

Just run the stack leaving the default password which is "password". Then once the container is deployed stop it then go into the "watchtower" container's "ENV" section and change it manually then recreate the container. See below for instructions on how to do it.

If your password does not use special characters you can safely ignore step 3.

Once you have completed that you are ready to click "Deploy the stack".

If you navigate to "Containers" in the left menu

You should now see your "watchtower" container in the list.

Step 3 - Fixing The Password

(Only if you have a password with special characters and have used the default).

If you left the password as default and need to change it.

Click on the container's check box and stop the container.

Once it has been stopped.

Double click on the the watchtower container to enter the "Actions" menu.

Click on "Duplicate/Edit".

and then click the "ENV" tab.

Under WATCHTOWER_NOTIFICATION_EMAIL_SERVER_PASSWORD replace "password" with your correct password

Click on "Deploy the stack".

Then click on "Replace".

This will fix the password bug with special characters.

Alternative - Install Watchtower with a single command. (Not advised).

Step 1 - SSH Into Your Raspberry Pi.

Connect to your Raspberry Pi over SSH (Secure Shell) and log in. You can use PUTTY if you are on Windows or a Terminal if you are on Mac or Linux.

ssh USER@RASPBERRYPIIPADDRESS

Enter your "user name" and "password".

Step 2 - Run The Command

If you just want to install Watchtower and have it automatically update your containers you can run one single command in your terminal.

However, it would be better to install Watchtower using the above method (a stack) as this gives you more control and options over the container.

There are also limits on the number of container images that can be downloaded from repositories like Dockerhub. These limits if reached will prevent any new image pulls from your IP address. This is another good reason to control the schedule using a docker compose stack.

If you are happy and except the risks then here is the command to run in a SSH terminal session.

$ docker run -d \
    --name watchtower \
    -v /var/run/docker.sock:/var/run/docker.sock \
    containrrr/watchtower