homelab-opentofu/modules/20-services-apps/watchtower

Watchtower Module

This module deploys a Watchtower container which automatically updates your running Docker containers when new images become available.

Features

• Automatic updates for Docker containers
• Configurable update schedule
• Optional cleanup of old images
• Notification support via shoutrrr
• Container monitoring options

Usage

To use this module in your root module, add the following code:

module "watchtower" {
  source = "./modules/20-services-apps/watchtower"
  
  # Basic configuration
  container_name = "watchtower"
  image_tag      = "latest"
  timezone       = "Australia/Sydney"
  
  # Update settings
  poll_interval   = 86400  # Check once per day (in seconds)
  cleanup         = true   # Remove old images after updating
  rolling_restart = true   # Update containers one by one
  
  # Optional notification settings
  enable_notifications = false
  # notification_url   = "discord://webhook-id/webhook-token"
  
  # Additional settings as needed
  # additional_env_vars = {
  #   WATCHTOWER_MONITOR_ONLY = "true"
  # }
}

Required Resources

This module leverages the generic docker-service module, which handles the Docker container deployment.

Input Variables

Name	Description	Type	Default
container_name	Name for the Watchtower container	string	"watchtower"
image_tag	The tag for the Watchtower container image	string	"latest"
restart_policy	Restart policy for the container	string	"unless-stopped"
timezone	Timezone for the container	string	"Etc/UTC"
cleanup	Remove old images after updating	bool	true
poll_interval	Poll interval (in seconds) for checking updates	number	86400
include_stopped	Include stopped containers when checking for updates	bool	false
revive_stopped	Restart stopped containers after updating	bool	false
rolling_restart	Restart containers one by one instead of all at once	bool	true
notification_url	URL for sending update notifications via shoutrrr	string	""
enable_notifications	Enable shoutrrr notifications	bool	false
additional_env_vars	Additional environment variables for Watchtower	map(string)	{}
additional_volumes	Additional volumes to mount in the container	list(object)	[]
labels	Labels to set on the container	map(string)	{}
ports	Ports to expose (rarely needed for Watchtower)	list(object)	[]
monitoring	Enable monitoring for the container	bool	true

Outputs

Name	Description
container_name	Name of the created Watchtower container
container_id	ID of the created Watchtower container
image_id	ID of the Watchtower image used

Notes

• Watchtower needs access to the Docker socket to monitor and update containers
• For security-conscious environments, consider limiting which containers Watchtower can update
• See the Watchtower documentation for more advanced configuration options