Extract ports, docker host, and remote-builder keys into variables.nix

Pulls the beszel hub / PVE / PBS ports, the docker-compose host's LAN
name, and the remote-builder client SSH keys out of scattered inline
literals across modules/hosts and into variables.nix as the single
source of truth, matching the existing pattern for other cross-host
references (nixCacheHost, nfsServerHost).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01La55Nsss8jZ7ZuzUV9mfot

hosts/nixos/home.nix

@@ -39,7 +39,7 @@
       [Desktop Entry]
       Type=Application
       Name=Proxmox (Chromium)
-      Exec=chromium --app=https://pve.${vars.homeDomain}:8006 --window-size=1920,1080 --window-position=0,0
+      Exec=chromium --app=https://pve.${vars.homeDomain}:${toString vars.pveWebPort} --window-size=1920,1080 --window-position=0,0
       Icon=${config.home.homeDirectory}/.local/share/icons/proxmox.png
       Terminal=false
       Categories=Hypervisor;
@@ -49,7 +49,7 @@
       [Desktop Entry]
       Type=Application
       Name=Proxmox Backup Server (Chromium)
-      Exec=chromium --app=https://${vars.pbsIp}:8007 --window-size=1920,1080 --window-position=0,0
+      Exec=chromium --app=https://${vars.pbsIp}:${toString vars.pbsWebPort} --window-size=1920,1080 --window-position=0,0
       Icon=${config.home.homeDirectory}/.local/share/icons/proxmox.png
       Terminal=false
       Categories=backup;
@@ -59,7 +59,7 @@
       [Desktop Entry]
       Type=Application
       Name=Proxmox (Firefox)
-      Exec=firefox --new-instance https://pve.${vars.homeDomain}:8006 --profile ProxmoxWebApp --window-size=1920,1080 --class ProxmoxWebApp
+      Exec=firefox --new-instance https://pve.${vars.homeDomain}:${toString vars.pveWebPort} --profile ProxmoxWebApp --window-size=1920,1080 --class ProxmoxWebApp
       Icon=${config.home.homeDirectory}/.local/share/icons/proxmox.png
       Terminal=false
       Categories=Hypervisor;
@@ -69,7 +69,7 @@
       [Desktop Entry]
       Type=Application
       Name=Proxmox Backup Server (Firefox)
-      Exec=firefox --new-window https://${vars.pbsIp}:8007 --profile PbsWebApp --window-size=1920,1080 --class PbsWebApp
+      Exec=firefox --new-window https://${vars.pbsIp}:${toString vars.pbsWebPort} --profile PbsWebApp --window-size=1920,1080 --class PbsWebApp
       Icon=${config.home.homeDirectory}/.local/share/icons/proxmox.png
       Terminal=false
       Categories=backup;

modules/beszel/enable-agent.nix

@@ -4,6 +4,6 @@
   services.beszel.agent.enable = true;
   services.beszel.agent.environment = {
     #DOCKER_HOST = "tcp://docker-socket-proxy:2375";
-    HUB_URL = "http://docker.${vars.homeDomain}:8090";
+    HUB_URL = "http://${vars.dockerHost}.${vars.homeDomain}:${toString vars.beszelHubPort}";
   };
 }

modules/nix-cache/server.nix

@@ -34,17 +34,10 @@
     createHome = true;
     home = "/var/lib/nixremote";
     shell = pkgs.bashInteractive;
-    # Provide remote builder public keys here (safe to commit public keys only):
+    # Client public keys allowed to use this host as a remote builder —
-    # openssh.authorizedKeys.keys = [ "ssh-ed25519 AAAA... client@host" ];
+    # single source of truth is vars.remoteBuilderAuthorizedKeys (safe to
-    #
+    # commit public keys only).
-    # Avoid absolute keyFiles paths here because they break pure flake evaluation.
+    openssh.authorizedKeys.keys = vars.remoteBuilderAuthorizedKeys;
-    openssh.authorizedKeys.keys = [
-      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIFDEA1S2ikpObREgbP5uVBWMxIOGbY8B+Wx7VTZK1m6t root@server"
-      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPAYIT9ormlmxZ0SziyDQaUntnKI8HK9/s3Qac1ZKjP2 root@docker"
-      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIKKKzoEPl/ZW9KBRHBcp6/ThOngGpwMv5EhkTlgC4aDf root@nixos"
-      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIGtOWOCS+ImHc7NehguoyD7PbonGosKMZqc9+QR3v/h root@nixos"
-      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHxXTQxFnArK5HXG7czeoybZebCGfxpUdusJkPn+BCSp root@server"
-    ];
   };
 
   services.openssh.enable = true;

variables.nix

@@ -10,13 +10,30 @@
   # Cross-host references (LAN hostnames/users other hosts reach over the network)
   nixCacheHost = "nix-cache"; # substituter/remote-builder hostname
   nfsServerHost = "server"; # NFS export source hostname
+  dockerHost = "docker"; # docker-compose stack host
 
   remoteBuilderUser = "nixremote"; # remote builder SSH user
 
+  # Public keys authorized to SSH in as remoteBuilderUser on the nix-cache
+  # host (modules/nix-cache/server.nix) — one per client host that's allowed
+  # to use it as a distributed builder.
+  remoteBuilderAuthorizedKeys = [
+    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIFDEA1S2ikpObREgbP5uVBWMxIOGbY8B+Wx7VTZK1m6t root@server"
+    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPAYIT9ormlmxZ0SziyDQaUntnKI8HK9/s3Qac1ZKjP2 root@docker"
+    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIKKKzoEPl/ZW9KBRHBcp6/ThOngGpwMv5EhkTlgC4aDf root@nixos"
+    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIGtOWOCS+ImHc7NehguoyD7PbonGosKMZqc9+QR3v/h root@nixos"
+    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHxXTQxFnArK5HXG7czeoybZebCGfxpUdusJkPn+BCSp root@server"
+  ];
+
   # System
   timeZone = "Australia/Brisbane";
   primaryUser = "nixos"; # main interactive user on every host
 
   # Storage
   storageRoot = "/tank"; # ZFS pool root on `server`
+
+  # Well-known ports for LAN services referenced from multiple hosts
+  beszelHubPort = 8090;
+  pveWebPort = 8006;
+  pbsWebPort = 8007;
 }