rename /cerulean -> /nix

nix/nixos/remote-deploy/default.nix

@@ -0,0 +1,82 @@
+{
+  config,
+  node,
+  lib,
+  pkgs,
+  hostname,
+  ...
+}: let
+  user = node.deploy.ssh.user;
+  cfg = config.users.users.${user};
+
+  DEFAULT_USER = "cerubld";
+
+  isStandardDeployUser = user == DEFAULT_USER;
+in {
+  assertions = [
+    {
+      assertion = builtins.length node.deploy.ssh.publicKeys != 0;
+      message = ''
+        The Cerulean deployment user `${user}` for node `${hostname}` must have at least
+        one publicKey authorized for ssh deployment! Try setting `nodes.nodes.<name>.deploy.ssh.publicKeys = [ ... ]` <3
+      '';
+    }
+    # {
+    #   assertion = cfg.isSystemUser && !cfg.isNormalUser;
+    #   message = ''
+    #     The Cerulean deployment user `${user}` for node `${hostname}` has been configured incorrectly.
+    #     Ensure `users.users.${user}.isSystemUser == true` and `users.users.${user}.isNormalUser == false`.
+    #   '';
+    # }
+  ];
+
+  warnings = lib.optional (node.deploy.warnNonstandardDeployUser && !isStandardDeployUser) ''
+    The Cerulean deplyment user `${user}` for node `${hostname}` has been overriden.
+    It is recommended to leave this user as `${DEFAULT_USER}` unless you TRULY understand what you are doing!
+    This message can be disabled by setting `<node>.deploy.warnNonstandardBuildUser = false`.
+  '';
+
+  # prefer sudo-rs over sudo
+  security.sudo-rs = {
+    enable = true;
+    wheelNeedsPassword = true;
+
+    # allow the build user to run nix commands
+    extraRules = [
+      {
+        users = [user];
+        runAs = "${node.deploy.user}:ALL";
+        commands = [
+          # "${pkgs.nix}/bin/nix"
+          "ALL" # XXX: WARNING: FIX: TODO: DO NOT FUCKING USE `ALL`
+        ];
+      }
+    ];
+  };
+
+  # XXX: WARNING: FIX: TODO: use `trusted-public-keys` instead
+  nix.settings.trusted-users = [user];
+
+  # ensure deployment user has SSH permissions
+  services.openssh.settings.AllowUsers = [user];
+
+  users = lib.mkIf isStandardDeployUser {
+    groups.${user} = {};
+
+    users.${user} = {
+      enable = true;
+      description = "Cerulean's user for building and remote deployment.";
+
+      isSystemUser = true;
+      group = user;
+
+      createHome = true;
+      home = "/var/lib/cerulean/cerubld";
+
+      useDefaultShell = false;
+      shell = pkgs.bash;
+
+      openssh.authorizedKeys.keys = node.deploy.ssh.publicKeys;
+    };
+  };
+}