hosts/bastille: automatically set hostname based on mac address

Author: mehbark

hosts/bastille/auto-hostname.nix

@@ -0,0 +1,39 @@
+{ pkgs, lib, ... }:
+let
+  # TODO: make this like a python script with a list of interfaces in order of preference
+  auto-hostname = pkgs.writeShellApplication {
+    name = "auto-hostname";
+
+    runtimeInputs = [
+      pkgs.hostname
+    ];
+
+    text = ''
+      if [[ -e "/sys/class/net/eno2/address" ]]; then
+        mac_file="/sys/class/net/eno2/address"
+      else
+        mac_file=/sys/class/net/enp0s25/address
+      fi
+
+      mac=$(cat $mac_file | tr -d '\r\n ' | tr ':' '-')
+
+      hostname "blade-$mac"
+    '';
+  };
+in {
+  networking.hostName = "";
+
+  systemd.services."auto-hostname" = {
+    wantedBy = [ "multi-user.target" ];
+    after = [ "network.target" ];
+
+    unitConfig = {
+      Description = "Automatically set the hostname ";
+    };
+
+    serviceConfig = {
+      Type = "oneshot";
+      ExecStart = "${lib.getExe auto-hostname}";
+    };
+  };
+}

hosts/bastille/blade.nix

@@ -1,5 +1,6 @@
 { modulesPath, pkgs, lib, ... }: {
   imports = [
+    ./auto-hostname.nix
     (import ../common/k3s.nix {})
     ../common/nix.nix
     ../common/sshd.nix