LinuxKit Nix - Linux on Mac Nix builder

hydra jobset

LinuxKit Nix makes it easy to build Linux binaries from a macOS machine using Nix. It's installing a VM using the native virtualization (Hypervisor.Framework) so it's quite liteweight compared to installing VirtualBox. The project also comes with an installation script that configures Nix to use the VM as a remote builder automatically.

Requirements

This project depends on Nix and a nixpkgs channel >= 18.03.

Installation

Fetch it from the NixOS binary cache:

nix-env -i /nix/store/jgq3savsyyrpsxvjlrz41nx09z7r0lch-linuxkit-builder
nix-linuxkit-configure

It'll write to:

• ~/.cache/nix-linuxkit-builder/, in particular ~/.cache/nix-linuxkit-builder/nix-state/console-ring is interesting
• ~root/.ssh/ for the SSH config
• /etc/nix/machines
• ~/Library/LaunchAgents/org.nix-community.linuxkit-builder.plist

Once installed the daemon should automatically start and stay running.

Debugging

To see if the daemon is running execute the following command and look at the first column. If it has a number (PID) it's running, if it's - then it's stopped:

launchctl list | grep linuxkit

You can force start it with:

launchctl start org.nix-community.linuxkit-builder

You can force stop it with:

launchctl stop org.nix-community.linuxkit-builder

If after you stop it you may want to check for processes, like:

pgrep vpnkit
pgrep linuxkit
pgrep hyperkit

If something goes wrong and it didn't stop properly, you can try:

pkill -F ~/.cache/nix-linuxkit-builder/nix-state/hyperkit.pid hyperkit

Troubleshooting

cannot build on 'ssh://nix-linuxkit': cannot connect to 'nix-linuxkit' ...

When runninng nix-linuxkit-configure, an SSH config is created at /var/root/.ssh/nix-linuxkit-ssh-config. Copy the contents of that SSH config into your regular SSH config located at ~/.ssh/config.

error: 'x86_64-linux' is require to build ...

Check the /etc/nix/nix.conf file for a builders option. It should either be set to @/etc/nix/machines or not set at all for LinuxKit Nix to work properly.

Another solution is to set export NIX_REMOTE_SYSTEMS=/etc/nix/machines before running the nix or nixops command.

cannot build on 'ssh://nix-linuxkit': cannot connect ...: Operation timed out

Something is wrong with LinuxKit. See the debugging section to try things out.

Leave an issue at https://github.com/nix-community/linuxkit-nix/issues

Uninstalling

# Remove configuration
rm -rf ~/.cache/nix-linuxkit-builder/

# Remove build machine
# (edit manually if you have other configuration here)
sudo rm -f /etc/nix/machines

# Remove LaunchAgent
launchctl stop org.nix-community.linuxkit-builder
rm -f ~/Library/LaunchAgents/org.nix-community.linuxkit-builder.plist

# Remove SSH config
# (edit manually if you have other configuration here)
sudo rm -rf /var/root/.ssh

# Uninstall Nix package
nix-env -e linuxkit-builder