Implementing Microservices on AWS with the Twelve-factor App – Part 1

The text outlines best practices for implementing containerized microservices using the Twelve-factor methodology, focusing on areas such as codebase management, dependency handling, configuration, backing services, and the separation of build, release, and run stages. It emphasizes the importance of maintaining a single codebase per application or microservice and recommends using container images for deployment, with Amazon ECR as an example for hosting these images. Dependency management should involve explicit declaration and isolation, ensuring dependencies are included in the deployment package. While configurations should vary between environments and be kept separate from code, they are accessed at runtime, which can be managed using tools like AWS Systems Manager. Backing services should be treated as attached resources, using URLs or credentials for access to allow seamless updates without code changes. The text further stresses building applications as stateless processes, with any state stored in external services to enhance scalability and stability, recommending one application process per container to facilitate this approach.