Dockerfile Generator
Generate a working Dockerfile for Node.js, Python, Go, or a static site, runs entirely in your browser.
About this tool
Pick a runtime, a port, and a start command, and get back a complete, working Dockerfile using that runtime’s official base image and the layer ordering that makes Docker’s build cache actually useful: dependency manifests copied and installed before the rest of the source, so an unrelated code change doesn’t force a full dependency reinstall on every build.
Go uses a multi-stage build, compiling in a full golang image and copying only the resulting static binary into a minimal distroless runtime image, the standard way to keep a Go container small without hand-editing a Dockerfile from scratch. Node.js and Python use their official slim/alpine base images with a straightforward single-stage build. The static site option copies files directly into Nginx’s default document root.
This is meant to produce a solid, working starting point, not a fully hardened production image: it does not add a non-root USER, a HEALTHCHECK, or pinned dependency lockfile versions beyond what your own package manifest already specifies. Review the output before shipping it.
Frequently asked questions
- Why does the Go option use two FROM lines?
- That is a multi-stage build: the first stage compiles the Go binary using the full golang image (which includes the Go toolchain), and the second stage copies only the compiled binary into a minimal runtime image that never sees the toolchain. This keeps the final image dramatically smaller than shipping the full Go compiler in production.
- Why is the start command entered as plain text instead of a code editor?
- It is converted into Docker’s CMD "exec form" (a JSON array of arguments) automatically by splitting on spaces, e.g. "npm start" becomes ["npm", "start"]. Exec form runs the process directly as PID 1 rather than through a shell, which is the recommended form for most containers since it forwards signals like SIGTERM correctly.
- Does this Dockerfile follow every production best practice?
- It follows the core ones (correct base image, cache-friendly layer order, multi-stage build for Go), but deliberately does not add things like a non-root user or a HEALTHCHECK, since those depend on details specific to your application. Treat this as a solid, correct starting point to adapt, not a finished production image.
- Is anything I enter sent anywhere?
- No. The Dockerfile is assembled entirely in your browser from string templates, no network request is made.
Continue learning
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