From cede676eb05e25b39fd3720dba83593c30b1d858 Mon Sep 17 00:00:00 2001
From: Sridhar Ratnakumar <srid@srid.ca>
Date: Tue, 26 Mar 2024 16:48:20 -0400
Subject: [PATCH] Setup distributed

---
 systems/darwin.nix        | 19 +++++++++++++++++++
 systems/github-runner.nix | 16 +++++++++++++++-
 2 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/systems/darwin.nix b/systems/darwin.nix
index 5935557..74ee6ca 100644
--- a/systems/darwin.nix
+++ b/systems/darwin.nix
@@ -8,6 +8,25 @@
     ../nix-darwin/zsh-completion-fix.nix
   ];
 
+  # Github runner CI
+  users = {
+    knownUsers = [ "github-runner" ];
+    forceRecreate = true;
+    users.github-runner = {
+      uid = 1009;
+      description = "GitHub Runner";
+      home = "/Users/github-runner";
+      createHome = true;
+      shell = pkgs.bashInteractive;
+      # NOTE: Go to macOS Remote-Login settings and allow all users to ssh.
+      openssh.authorizedKeys.keys = [
+        # github-runner VM's /etc/ssh/ssh_host_ed25519_key.pub
+        "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIJUJvyuUnIs2q2TkJq29wqJ6HyOAeMmIK8PcH7xAlpVY root@github-runner"
+      ];
+    };
+  };
+  nix.settings.trusted-users = [ "github-runner" ];
+
   nixpkgs.hostPlatform = "aarch64-darwin";
 
   environment.systemPackages = with pkgs; [
diff --git a/systems/github-runner.nix b/systems/github-runner.nix
index e3b6ae2..8cd3a7c 100644
--- a/systems/github-runner.nix
+++ b/systems/github-runner.nix
@@ -2,8 +2,9 @@
 # - [x] Intial config
 # - [x] Colmena deploy, with keys from 1Password.
 # - [x] Github Runners
-# - [ ] Distributed builder to host (macOS)
+# - [x] Distributed builder to host (macOS)
 # - [x] Refactor, to allow multiple repos (then remove easy-github-runners.nix)
+# - [ ] Refactor into own dir
 { flake, pkgs, lib, ... }:
 
 let
@@ -29,6 +30,7 @@ let
           ];
           url = "https://github.com/${user}/${repoName}";
         })));
+  hostIP = "10.37.129.2"; # Find out using `ifconfig` on host, looking for bridge101
 in
 {
   imports = [
@@ -62,4 +64,16 @@ in
   services.github-runners = mkPersonalRunners "srid" {
     perpetuum.num = 2;
   };
+
+  # macOS remote builder
+  nix.distributedBuilds = true;
+  nix.buildMachines = [{
+    hostName = hostIP;
+    systems = [ "aarch64-darwin" "x86_64-darwin" ];
+    # supportedFeatures = [ "kvm" "benchmark" "big-parallel" ];
+    maxJobs = 6; # 6 cores
+    protocol = "ssh-ng";
+    sshUser = user;
+    sshKey = "/etc/ssh/ssh_host_ed25519_key";
+  }];
 }