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.dockerignore Generator

Create a Docker ignore file for Node.js, Python, Java, Go, Rust, PHP, and .NET projects.

Last updated: March 2026 | By Workshelve Team

Choose a stack to add language-specific exclusions.

Supports comments, wildcards, directory patterns, character classes like *.py[cod], and negation with !.

Configure options to generate .dockerignore...

The tester approximates Docker .dockerignore behavior including directory matches, Go-style wildcards such as [cod], **, and order-sensitive ! negation.

What is a .dockerignore File?

A .dockerignore file tells Docker which files and folders to leave out of the build context. It works like .gitignore, but for Docker builds instead of Git.

When you run docker build, Docker sends files from your project into the build context. Excluding dependency folders, logs, local secrets, editor files, and generated output can make builds faster and reduce accidental leaks.

A good Docker ignore file is especially useful for Node.js, Python, Java, Go, Rust, PHP, and .NET projects where local dependency folders or cache directories can be large.

Docker Ignore Generator for Common Project Types

Choose a project type, review the common exclusions, then copy or download the generated file as .dockerignore.

Step 1: Select your project type.
Step 2: Enable or disable common exclusion groups.
Step 3: Add any project-specific patterns.
Step 4: Save the output as .dockerignore beside your Dockerfile.
Step 5: Run docker build.

Node.js .dockerignore Example

A typical Node.js Docker ignore file:

# Secrets and credentials
.env
.env.*
!.env.example
*.key
*.pem

# Node.js
node_modules/
.npm/
.yarn/
dist/
build/
.next/
.turbo/
coverage/

# Version control
.git/
.gitignore

# Logs
*.log
logs/
npm-debug.log*
yarn-debug.log*

# OS files
.DS_Store
Thumbs.db
• Excludes local dependencies that should be installed during the image build.
• Keeps secrets and local credentials out of the build context.
• Removes editor, log, cache, and OS files from the Docker build input.
• Keeps optional files like README, LICENSE, docs, and tests under your control.

How to Test .dockerignore Patterns

Use the pattern tester to check whether a path would be excluded. Directory patterns like node_modules/ should match nested files such as node_modules/react/index.js.

Pattern order matters. A later negation pattern starting with ! can re-include a file that was previously excluded, such as !.env.example.

Frequently Asked Questions

Where should I put .dockerignore?

Put .dockerignore in the build context root, usually the same folder where you run docker build. It is commonly placed beside the Dockerfile.

Does .dockerignore reduce Docker image size?

It can, but its main job is reducing the build context. Image size only changes if excluded files would otherwise be copied into the image.

Should I exclude node_modules?

Usually yes for Node.js images. The Dockerfile should install dependencies inside the image so the result matches the container environment.

Should README, docs, and tests be excluded?

Only if your build does not need them. Some projects use tests, docs, or metadata during build, so this generator keeps those optional.

Can .dockerignore include negation rules?

Yes. Use ! to re-include a file after a broader exclusion. A common example is excluding .env.* but keeping !.env.example.

Does Docker Compose use .dockerignore?

Yes. Compose uses .dockerignore when it builds an image from a local build context.