Nixinate 🕶️

Nixinate is a proof of concept that generates a deployment script for each nixosConfiguration you already have in your flake, which can be ran via nix run, thanks to the apps attribute of the flake schema.

Usage

To add and configure nixinate in your own flake, you need to:

1. Add the result of nixinate self to the apps attribute of your flake.
2. Add and configure _module.args.nixinate to the nixosConfigurations you want to deploy

Below is a minimal example:

{
  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixos-23.05";
    nixinate.url = "github:matthewcroughan/nixinate";
  };

  outputs = { self, nixpkgs, nixinate }: {
    apps = nixinate.nixinate.x86_64-linux self;
    nixosConfigurations = {
      myMachine = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          (import ./my-configuration.nix)
          {
            _module.args.nixinate = {
              host = "itchy.scratchy.com";
              sshUser = "matthew";

              # Or optionally pass a 'short' hostname that is defined in ssh config
              sshConfigHost = "itchy-scratchy";

              buildOn = "remote"; # valid args are "local" or "remote"
              substituteOnTarget = true; # if buildOn is "local" then it will substitute on the target, "-s"
              hermetic = false;
            };
          }
          # ... other configuration ...
        ];
      };
    };
  };
}

Each nixosConfiguration you have configured should have a deployment script in apps.nixinate, visible in nix flake show like this:

$ nix flake show
git+file:///etc/nixos
├───apps
│   └───nixinate
│       └───myMachine: app
└───nixosConfigurations
    └───myMachine: NixOS configuration

To finally execute the deployment script, use nix run .#apps.nixinate.myMachine

Example Run

[root@myMachine:/etc/nixos]# nix run .#apps.nixinate.myMachine
🚀 Deploying nixosConfigurations.myMachine from /nix/store/279p8aaclmng8kc3mdmrmi6q3n76r1i7-source
👤 SSH User: matthew
🌐 SSH Host: itchy.scratchy.com
🚀 Sending flake to myMachine via nix copy:
([email protected]) Password:
🤞 Activating configuration on myMachine via ssh:
([email protected]) Password:
[sudo] password for matthew:
building the system configuration...
activating the configuration...
setting up /etc...
reloading user units for matthew...
setting up tmpfiles
Connection to itchy.scratchy.com closed.

Available arguments via _module.args.nixinate

• host string

  A string representing the hostname or IP address of a machine to connect to via ssh.

• sshUser string

  A string representing the username a machine to connect to via ssh.

• sshConfigHost string

  A string representing an entry in ssh config. If provided, it takes precedence over host and sshUser.

• buildOn "remote" or "local"

  • "remote"

    Push the flake to the remote, build and activate entirely remotely, returning logs via SSH.

  • "local"

    Build the system closure locally, copy to the remote and activate.

• hermetic bool

  Whether to copy Nix to the remote for usage when building and activating, instead of using the Nix which is already installed on the remote.

• substituteOnTarget bool

  Whether to fetch closures and paths from the remote, even when building locally. This makes sense in most cases, because the remote will have already built a lot of the paths from the previous deployment. However, if the remote has a slow upload bandwidth, this would not be a good idea to enable.

• nixOptions listOf strings

  Extra options passed to all invocations of nix.

• sshOptions listOfStrings

  Extra options passed to all invocations of ssh.

Project Principles

• No Premature Optimization: Make it work, then optimize it later if the optimization is taking a lot of time to figure out now.
• KISS: Keep it simple, stupid. Unnecesary complexity should be avoided.