Keep Docker development, staging, and production environments consistent

Link copied

Attach video time

Docker makes it easier to keep development, staging, and production consistent. Define the application services in docker-compose.yml, then use the same images and versions in every environment. When staging and production run the exact versions you use locally, differences between environments are much less likely to occur.

Third-party backing services usually vary between environments, so configure them with environment variables rather than hard-coding their settings in the application. The same code can then run everywhere while environment variables direct requests to the appropriate service.

For example, you may want to test Google Analytics locally without sending development traffic to your production account. Create a separate Google Analytics account for testing and store its measurement ID in your local .env file. Then update the Analytics snippet so it reads the ID from an environment variable instead of containing a fixed value.

When Docker starts the container, it loads the environment variables from .env, and your local Analytics code uses the test account. Your staging and production environments can use their own .env files with the corresponding Analytics IDs, while the application code remains unchanged.

Do not commit .env files to version control. They often contain credentials and environment-specific configuration. Instead, make setting and updating environment variables part of your deployment process. This ensures that each deployment receives the correct values for its environment and keeps those values out of the codebase.