nixinate/README.md
matthewcroughan 4a356409ca Add support for hermetic remote builds
A hermetic remote rebuild is when Nixinate sends a specific Nix binary
to the remote first, then uses it when activating a system closure,
rather than using the Nix that is already on the remote. This is
defaulted to false for the time being, as the bandwidth usage can be
high. This allows users to avoid the need to bootstrap the remote first
by enabling flakes on the remote Nix binary.
2022-05-29 19:02:50 +01:00

2.9 KiB

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-21.11";
    nixinate.url = "github:matthewcroughan/nixinate";
  };

  outputs = { self, nixpkgs, nixinate }: {
    apps = nixinate.nixinate.x86_64-linux self;
    nixosConfigurations = {
      myMachine = nixpkgs.lib.nixosSystem {
        modules = [
          (import ./my-configuration.nix)
          {
            _module.args.nixinate = {
              host = "itchy.scratchy.com";
              sshUser = "matthew";
              buildOn = "remote"; # valid args are "local" or "remote"
	            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:
(matthew@itchy.scratchy.com) Password: 
🤞 Activating configuration on myMachine via ssh:
(matthew@itchy.scratchy.com) 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.

  • 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.