Why Watchtower?

To automatically detect and update a Docker container when a new version of an image is available, you would typically use a combination of Docker Hub (or another Docker registry), a continuous integration/continuous deployment (CI/CD) pipeline, and a container orchestration tool like Kubernetes or Docker Swarm. Watchtower is a popular open-source tool that automates this process.

How Watchtower Works

Watchtower monitors running Docker containers and watches for updates to the images they are running. When a new image is available, Watchtower pulls the new image, stops the running container, and restarts it with the new image, maintaining the original container’s settings (such as port mappings and mounted volumes).

Use Case for Watchtower

1. Continuous Deployment: Automatically deploy new versions of your application without manual intervention, ensuring you always run the latest version.
2. Security Updates: Automatically update containers with the latest security patches by pulling updated base images.
3. Operational Simplicity: Reduce the operational overhead of managing container updates manually.

Watchtower provides an efficient and straightforward way to automate the deployment of updated Docker images, ensuring that your containers are always running the latest version. By integrating Watchtower into your deployment workflow, you can achieve continuous deployment and improve the security and stability of your applications with minimal manual effort.