Dockerfile Helper
Browse ready-to-use Dockerfile snippets for common stacks. Click any snippet to view and copy it.
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About Dockerfile Helper
The Dockerfile Helper is a reference library of ready-to-use Dockerfile and container snippets for the stacks people containerise most often — Node, Python, Go, and Nginx — alongside the patterns that make an image production-worthy: multi-stage builds, health checks, build arguments, and a matching .dockerignore. Rather than remembering exact syntax or copying an old project’s Dockerfile and hoping it still reflects current practice, you pick the pattern you need, read it, and copy it. Every snippet is written to be a sound starting point rather than the shortest thing that builds, and the whole library ships with the page, so it works offline.
Key features
- Node.js images in both a simple Alpine form and a multi-stage production build
- Python with a virtual environment, and Go as a multi-stage build producing a minimal final image
- Nginx for serving a static site, plus an Nginx config for single-page apps that need history-mode routing
- A HEALTHCHECK instruction pattern for containers behind an orchestrator
- An ARG and ENV pattern showing the difference between build-time and runtime configuration
- A .dockerignore for Node projects, which is what keeps node_modules out of the build context
- Tag filtering to narrow the library to the stack you are working in
- One-click copy on every snippet
- Entirely static and local — the snippets are part of the page, so nothing is fetched or generated remotely
How to use it
- Filter by tag, or scan the list for the stack you are containerising.
- Click a snippet to read it in full.
- Copy it into a Dockerfile at your project root.
- Adjust the base image tag, the exposed port, and the start command to match your application.
- Add the .dockerignore snippet as well — it is the single easiest build-speed win.
Tips & common mistakes
- Use a multi-stage build for anything with a compile or bundle step. Build tools, dev dependencies, and source files stay in the first stage, and the final image ships only what actually runs.
- Copy your manifest first and install dependencies before copying the rest of the source. Docker caches layers, so this one ordering change turns most rebuilds from minutes into seconds.
- A .dockerignore is not optional. Without one, node_modules and .git are uploaded into the build context on every build, which is slow and can leak history into an image.
- Pin base images to a specific tag rather than latest. A build that succeeded last week and fails today with no code change is very often an unpinned base image that moved underneath you.
- ARG is build-time and ENV is runtime, and neither is a secret. Both are visible in the image history, so credentials belong in a runtime secret mechanism, not in a build argument.
- Run as a non-root user in the final stage. Most base images default to root, and switching users is a one-line change that removes a whole class of container escapes.
- A HEALTHCHECK is what lets an orchestrator tell "running" from "working". Without one, a container whose process is alive but wedged is treated as perfectly healthy.
- Need to validate or reformat the `.env` file this container reads? Use the Environment Var Formatter.
- Scheduling a recurring job inside it? Build the schedule expression with the Cron Expression Generator.