feat: create shared extraHosts module with Tailscale IPs

- Create modules/network/extraHosts.nix with Tailscale IP mappings
- Replace hardcoded networking.extraHosts in all machine configs
- Add extraHosts module import to all machines
- Enable Tailscale service by default in the module
- Use Tailscale mesh network IPs for reliable connectivity

machines/congenital-optimist/configuration.nix

@@ -12,6 +12,9 @@
     # Security modules
     ../../modules/security/ssh-keys.nix
     
+    # Network modules
+    ../../modules/network/extraHosts.nix
+    
     # Hardware modules
     ../../modules/hardware/amd-workstation.nix
     
@@ -45,8 +48,7 @@
         path = "/boot";
       }
     ];
-  };
-# ZFS services for this machine
+  };  # ZFS services for this machine
   services.zfs = {
     autoScrub.enable = true;
     trim.enable = true;

machines/grey-area/configuration.nix

@@ -8,6 +8,7 @@
     # Shared modules
     ../../modules/common/base.nix
     ../../modules/network/common.nix
+    ../../modules/network/extraHosts.nix
     ../../modules/virtualization/podman.nix
     ../../modules/virtualization/libvirt.nix
     ../../modules/virtualization/incus.nix
@@ -65,11 +66,6 @@
   networking.hostName = "grey-area"; 
   networking.networkmanager.enable = true;
 
-  # Add hostname resolution for sleeper-service NFS server
-  networking.extraHosts = ''
-    10.0.0.8 sleeper-service
-  '';  
-
   # Set your time zone.
   time.timeZone = "Europe/Oslo";
 

machines/reverse-proxy/configuration.nix

@@ -4,6 +4,7 @@
   imports = [ 
     ./gandicloud.nix
     ../../modules/common/base.nix
+    ../../modules/network/extraHosts.nix
     ../../modules/users/sma.nix
     ../../modules/security/ssh-keys.nix
   ];

machines/sleeper-service/configuration.nix

@@ -5,6 +5,7 @@
     ../../modules/security/ssh-keys.nix
     # Network configuration
     ./network-sleeper-service.nix
+    ../../modules/network/extraHosts.nix
     # Services
     ./nfs.nix
     ./services/transmission.nix

modules/network/extraHosts.nix

@@ -0,0 +1,26 @@
+# Network hostname resolution module
+# Provides consistent hostname-to-IP mapping across all home lab machines
+# Uses Tailscale IPs for reliable connectivity across the mesh network
+
+{ config, lib, ... }:
+
+{
+  # Add hostname entries for all home lab machines using Tailscale IPs
+  networking.extraHosts = ''
+    # Home Lab Infrastructure (Tailscale mesh network)
+    100.109.28.53   congenital-optimist
+    100.81.15.84    sleeper-service  
+    100.119.86.92   grey-area
+    100.96.189.104  reverse-proxy vps1
+    
+    # Additional network devices
+    100.103.143.108 pihole
+    100.126.202.40  wordpresserver
+  '';
+  
+  # Enable Tailscale by default for all machines using this module
+  services.tailscale = {
+    enable = true;
+    useRoutingFeatures = "client";
+  };
+}