ofborg: add example configuration

modules/examples/ofborg.nix

@@ -0,0 +1,30 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+{
+  # Logs are enabled by default.
+  # $ tail -f /var/log/ofborg.log
+  services.ofborg.enable = true;
+  services.ofborg.package = (import <ofborg> {}).ofborg.rs;
+  # services.ofborg.configFile = "/var/lib/ofborg/config.json";
+
+  services.nix-daemon.enable = true;
+
+  nix.package = pkgs.nixUnstable;
+
+  nix.gc.automatic = true;
+  nix.gc.options = "--max-freed $((25 * 1024**3 - 1024 * $(df -P -k /nix/store | tail -n 1 | awk '{ print $4 }')))";
+
+  users.knownGroups = [ "ofborg" ];
+  users.knownUsers = [ "ofborg" ];
+
+  # Used for backwards compatibility, please read the changelog before changing.
+  # $ darwin-rebuild changelog
+  system.stateVersion = 2;
+
+  # You should generally set this to the total number of logical cores in your system.
+  # $ sysctl -n hw.ncpu
+  nix.maxJobs = 1;
+  nix.buildCores = 1;
+}