Using Docker Without Overcomplicating Deployment

Use containers for a concrete reason

Good reasons include system dependencies, multiple cooperating services, consistent CI builds, or a hosting platform that expects a container. A static site or a single conventional runtime may already deploy cleanly without one.

Write down the problem Docker solves before adding it. If the answer is only “modern deployment,” the team may be purchasing complexity without a benefit.

• Pin the runtime and dependency versions
• Use a small trusted base image
• Keep build tools out of the final image
• Run the application as a non-root user

Build one clear image

Use a multi-stage build, copy dependency manifests before source code for useful caching, and include a .dockerignore. Configuration belongs in environment variables or mounted files, not baked credentials.

The container should write important state to a database or managed volume. Treat its local filesystem as disposable, and send logs to standard output so the platform can collect them.

• Add a health check that reflects real readiness
• Handle termination signals and finish active requests
• Set sensible memory and CPU limits
• Scan dependencies and the final image

Keep operations boring

Tag images with an immutable commit or release identifier. Deploy the exact image that passed tests and keep the previous tag available. A rollback should be selecting a known image, not rebuilding old source with new dependencies.

Document one local command, one build command, one deployment path, and one place to inspect logs. If only the original author can operate it, consistency has not been achieved.