Harmonic

Harmonic is pre-release and experimental. Don't run it on machines you care about.

Harmonic is an opinionated, experimental Nix installer.

Status

Harmonic is pre-release and experimental. It is not ready for you to use! Please don't use it on a machine you are not planning to obliterate!

Planned support:

• Multi-user x86_64 Linux with systemd init
• Multi-user aarch64 Linux with systemd init
• Multi-user x86_64 MacOS
  • Note: User deletion is currently unimplemented, you need to use a user with a secure token and dscl . -delete /Users/_nixbuild* where * is each user number.
• Multi-user aarch64 MacOS
  • Note: User deletion is currently unimplemented, you need to use a user with a secure token and dscl . -delete /Users/_nixbuild* where * is each user number.
• Single-user x86_64 Linux with systemd init
• Single-user aarch64 Linux with systemd init
• Others...

Installation Differences

Differing from the current official Nix installer scripts:

• Nix is installed with the nix-command and flakes features enabled in the nix.conf
• Harmonic stores an installation receipt (for uninstalling) at /nix/receipt.json

Motivations

The current Nix installer scripts do an excellent job, however they are difficult to maintain. Subtle differences in the shell implementations, and certain characteristics of bash scripts make it difficult to make meaningful changes to the installer.

Our team wishes to experiment with the idea of an installer in a more structured language and see if this is a worthwhile alternative. Along the way, we are also exploring a few other ideas, such as:

• offering users a chance to review an accurate, calculated install plan
• keeping an installation receipt for uninstallation
• offering users with a failing install the chance to revert
• doing whatever tasks we can in parallel

So far, our explorations have been quite fruitful, so we wanted to share and keep exploring.

Building

Harmonic is pre-release and we do not provide binaries at this time.

Since you'll be using Harmonic to install Nix on systems without Nix, the default build is a static binary.

Build it on a system with Nix:

nix build github:determinatesystems/harmonic

Then copy the result/bin/harmonic to the machine you wish to run it on.

Running

Harmonic must be run as root, as it needs to alter the system and cannot elevate privileges without significant complexity.

Install Nix with default options:

# Linux
./harmonic install linux-multi

# Mac
./harmonic install darwin-multi

To observe verbose logging, either use harmonic -v, this tool also respects the RUST_LOG environment. (Eg RUST_LOG=harmonic=trace harmonic).

Harmonic supports many of the options the current official Nix installer scripts. Review harmonic --help for details.

Uninstalling

You can remove a Harmonic-installed Nix by running

./harmonic uninstall

If you're on Mac and trying to run this over SSH, ensure you enable root by running dsenableroot, running the uninstall, then running dsenableroot -d to disable root again.