Validators
Dockerfile Validator
Validate your Dockerfile syntax to ensure clean and efficient container builds. Get detailed error messages with line-specific diagnostics to catch mistakes before they hit your CI/CD pipeline.
Validate your Dockerfile syntax to ensure clean and efficient container builds. Get detailed error messages with line-specific diagnostics to catch mistakes before they hit your CI/CD pipeline.
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Tip
Combine multiple RUN commands using '&&' to significantly reduce the number of layers in your image.
Best Practice
Always use a .dockerignore file to exclude node_modules, .git, and other heavy folders from the build context.
FROM instructionlatest tags which makes builds non-reproducible over timeDid You Know?
The order of instructions matters: changing a line early in the Dockerfile invalidates the cache for all subsequent lines.
Q: Does this validator support multi-stage builds? A: Yes, it recognizes multi-stage syntax including stage naming and 'COPY --from' instructions.
Q: What is the benefit of pinning an image version? A: Pinning prevents your build from breaking if the upstream base image is updated with incompatible changes.
Q: Why are my errors not clearing? A: Ensure you have fixed the specific line mentioned; the validator re-evaluates the entire file on every change.
Tip
Use the JSON array syntax for CMD and ENTRYPOINT (["cmd", "arg"]) to ensure signals like SIGTERM are handled correctly.