Copy instruction
The Dockerfile COPY instruction copies files or directories from a build context or another build stage into an image’s filesystem.
Learn Docker in a Month of Lunches, Second Edition
A COPY instruction is a Dockerfile directive that copies files or directories into the image filesystem.
- How it is used
- Places application files into Docker images, including source files for builds and compiled artifacts for final stages.
- How deep it goes
- Defines source and target paths, then works through copy ordering, multi-stage copying, and image-size consequences.
- Examples
- Uses a Node.js application file, a Maven-built JAR, and a comparison between copying an entire directory and copying only its app folder.
- What you can do after
- Build it from scratch: write COPY instructions that place needed files in an image while avoiding unnecessary copied content.
Read how Learn Docker in a Month of Lunches, Second Edition explains copy instruction →
Podman in Action: Secure, rootless containers for Kubernetes, microservices, and more
The COPY directive adds files, directories, or archive contents from the build host to the image filesystem.
- How it is used
- Adds build-context content to an image filesystem while constructing a Podman image.
- How deep it goes
- Explains sources, destinations, rootfs population, and practical builds, but defers detailed path and archive semantics.
- Examples
- Uses index.html copied into an HTTP server document root and shows the resulting podman build output.
- What you can do after
- Build it into an image by placing files in a context directory and invoking podman build.
Related concepts
- file systemuses · A file system is a software-managed structure and interface for organizing, naming, storing, and accessing files and directories on storage.
- Dockerfileused by · A Dockerfile is a text file containing declarative instructions for building a container image and specifying its contents and runtime metadata.
- context directoryuses · A context directory is a directory containing the files and build instructions made available to a container image build.
- container imageuses · A container image is a packaged filesystem and configuration artifact from which a container can be created and run.
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