John CostaandClaude Opus 4.8
aa7fef3d1d
- Fixes #1801. - When `container image save` runs without `--output`, stdout carries the OCI tar archive. The command writes the archive bytes to stdout and then `print(reference)`s each saved image reference to stdout afterward, appending non-archive text after the tar EOF marker, which will cause strict tar/OCI consumers to fail. - This routes the saved-reference list to stderr in the no-`--output` branch, so stdout contains only archive bytes. When saving to a file via `--output`, stdout is free, so the references continue to print to stdout exactly as before. Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
container
container is a tool that you can use to create and run Linux containers as lightweight virtual machines on your Mac. It's written in Swift, and optimized for Apple silicon.
The tool consumes and produces OCI-compatible container images, so you can pull and run images from any standard container registry. You can push images that you build to those registries as well, and run the images in any other OCI-compatible application.
container uses the Containerization Swift package for low-level container, image, and process management.
Get started
Requirements
You need a Mac with Apple silicon to run container. To build it, see the BUILDING document.
container is supported on macOS 26, since it takes advantage of new features and enhancements to virtualization and networking in this release. We do not support older versions of macOS and the container maintainers typically will not address issues that cannot be reproduced on macOS 26.
Initial install
Download the latest signed installer package for container from the GitHub release page.
To install the tool, double-click the package file and follow the instructions. Enter your administrator password when prompted, to give the installer permission to place the installed files under /usr/local.
Start the system service with:
container system start
Upgrade or downgrade
For both upgrading and downgrading, you can manually download and install the signed installer package by following the steps from initial install or use the update-container.sh script (installed to /usr/local/bin).
If you're upgrading or downgrading, you must stop your existing container:
container system stop
To upgrade to the latest release, simply run the command below:
/usr/local/bin/update-container.sh
To downgrade, you must uninstall your existing container (the -k flag keeps your user data, while -d removes it):
/usr/local/bin/uninstall-container.sh -k
/usr/local/bin/update-container.sh -v 0.3.0
Start the system service with:
container system start
Uninstall
Use the uninstall-container.sh script (installed to /usr/local/bin) to remove container from your system. To remove your user data along with the tool, run:
/usr/local/bin/uninstall-container.sh -d
To retain your user data so that it is available should you reinstall later, run:
/usr/local/bin/uninstall-container.sh -k
Next steps
- Take a guided tour of
containerby building, running, and publishing a simple web server image. - Learn how to use various
containerfeatures. - Read a brief description and technical overview of
container. - Browse the full command reference.
- Build and run
containeron your own development system. - View the project API documentation.
Contributing
Contributions to container are welcome and encouraged. Please see our main contributing guide for more information.
Project Status
The container project is currently under active development. Its stability, both for consuming the project as a Swift package and the container tool, is only guaranteed within patch versions, such as between 0.1.1 and 0.1.2. Minor version releases may include breaking changes until we reach a 1.0.0 release.