An application image runs in multiple environments, and each environment uses different certificates and ports, what is the best practice to deploy the containers?

Creating a Dockerfile for each environment leads to multiple similar images, violating the 'build once, run anywhere' principle and increasing maintenance overhead.

While Docker secrets are suitable for sensitive data, creating separate Dockerfiles for each environment to embed these is inefficient and contradicts the goal of a single, reusable image.

Creating distinct images for every environment results in image proliferation, making the build and deployment process less efficient and harder to manage due to redundant image builds.

By externalizing environment-specific configurations into separate config files, the core application image remains immutable and generic. This approach allows the same image to be deployed across multiple environments with different settings applied at runtime, promoting consistency and easier management.