Google Cloud Container Builder vs Watchtower: What are the differences?

### Key differences between Google Cloud Container Builder and Watchtower

<Google Cloud Container Builder and Watchtower are two popular tools used for container orchestration, but they have key differences that differentiate them.>

1. **Build Triggering Mechanism**: Google Cloud Container Builder relies on webhooks to trigger builds based on events within a source code repository, such as commits or merges. On the other hand, Watchtower continuously monitors running containers for changes to their base images and automatically updates them without the need for explicit triggering.

2. **Integration with CI/CD Pipelines**: Google Cloud Container Builder seamlessly integrates with popular CI/CD tools like Jenkins and GitHub Actions, allowing for automated build and deployment processes. Watchtower, on the other hand, is primarily focused on image updating functionality and lacks direct integration with CI/CD pipelines.

3. **Supported Container Registries**: Google Cloud Container Builder natively supports Google Container Registry for storing Docker images, providing a tightly integrated solution within the Google Cloud Platform ecosystem. Watchtower, on the other hand, is agnostic to the container registry used and can work with any standard Docker-compatible registry.

4. **Scope of Functionality**: Google Cloud Container Builder is designed specifically for building container images from source code, providing a complete end-to-end solution for CI/CD workflows. Watchtower, on the other hand, specializes in automatic updates of container images during runtime, focusing on maintaining the security and efficiency of running containers.

5. **License and Cost**: Google Cloud Container Builder is a managed service provided by Google Cloud Platform with pricing based on build and storage usage, making it a convenient solution for users already within the GCP ecosystem. Watchtower, on the other hand, is an open-source project released under the Apache License, making it a cost-effective option for users looking to manage container image updates independently.

6. **Community Support and Development**: Google Cloud Container Builder benefits from the extensive support and development resources of Google Cloud Platform, ensuring regular updates and feature enhancements. Watchtower, as an open-source project, relies on community contributions and may have a more diverse range of features and customizations driven by user demand.

In Summary, Google Cloud Container Builder excels in CI/CD workflows and tight integration with GCP, while Watchtower focuses on automated image updating and flexibility across container registries.