A .dockerignore file lives next to your Dockerfile and controls which files are excluded from the Docker build context.
- Why use
.dockerignore?- ✅ Faster builds: smaller context → quicker transfer to the Docker daemon.
- ✅ Smaller images: avoid accidentally copying huge or irrelevant files.
- ✅ Better security: prevents secrets, credentials, .git/, etc. from leaking into images.
Example Project Layout
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├── .dockerignore
├── Dockerfile
├── app/
│ └── ...
├── node_modules/
└── secrets.env
.dockerignore:
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# don't send deps or creds into the image
node_modules
secrets.env
# logs, caches, etc.
*.log
When you run docker build ., Docker will send only:
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Dockerfile
app/ (and its contents)
…not node_modules/, secrets.env, or any .log files.
