docker2lxc is a shell function that converts a Docker image into a tarball (template.tar.gz) that can be used as an LXC template. A more descriptive name for this tool could be docker2rootfs, as its primary function is to export the root filesystem of a Docker image.
- Exports the root filesystem of a Docker image as a tarball.
- Creates a base template for use in LXC containers.
Note: This tool only handles the filesystem export. It does not configure the container. Users must manually handle the following tasks:
- Configuring the entry point for the LXC container.
- Adding necessary configuration files to the root filesystem.
- Mounting additional volumes.
- Setting up CPU, memory, and other resource limits.
- Configuring networking.
To install docker2lxc, append the contents of entry.sh to your shell's run-command file (e.g., .bashrc, .zshrc, etc.):
cat entry.sh >> ~/.bashrc # for bashcat entry.sh >> ~/.zshrc # for zsh... or source the file to import the function when needed:
source entry.shNote: Ensure that you are in the same directory as the cloned repository when executing the commands above.
To use the function locally, provide the name of the Docker image (as you would with docker pull or docker run) and optionally specify the tarball's filename. By default, the output tarball is named template.tar.gz:
docker2lxc <image> [<output-filename.tar.gz>]Example:
docker2lxc ubuntu:20.04 my-template.tar.gzYou can also run docker2lxc on a remote machine via SSH. This is useful when:
- Docker is not installed on your local machine.
- Your local machine lacks the necessary processing power or storage.
- You need the template for a different platform or architecture than your local system.
To run the function over SSH:
ssh <remote-host> "$(declare -f docker2lxc); docker2lxc <image>" > <output-filename.tar.gz>Example:
ssh user@remote-server "$(declare -f docker2lxc); docker2lxc ubuntu:20.04" > ubuntu-template.tar.gz