Managing multiple environments with Docker consists of a variety of tasks such as managing images, setting up containers, and configuring environment variables. Here’s how to manage different environments with Docker:
1. Separating Environments: You can setup dev, staging, and production environments in different Docker containers. Each Docker container will run independently of the others with its own settings and configurations.
1. Docker Compose: One of the most common ways to manage these environments is by using Docker Compose. Docker Compose allows you to define and run multi-container applications with Docker. You can take advantage of the ‘extends’ functionality in Docker Compose to have a base service defined which all environments extend, then override configurations as needed per environment.
1. Docker Images: You can create different images for different environments. For example, your development image might include debugging tools while your production image doesn’t.
1. Environment Variables: You can utilize environment variables to implement per-environment configuration. For security, it is recommended to use Docker secrets instead of environment variables for sensitive data.
1. Docker Networks: You can use Docker’s network feature to isolate containers by environment, this can help to prevent accidental cross-environment communication.
1. Dockerfiles: You can create multiple Dockerfiles for different environments and specify the Dockerfile to be used when building the image. Each Dockerfile can have different build, package, and environment configurations.
Remember, a key point of managing multiple environments is to ensure as much parity as possible i.e. all your environment should be as close as possible to each other’s configurations to prevent bugs that appear in one and not the other.
