Add network-libvirtd.nix for libvirtd environments.

network-libvirtd.nix

@@ -0,0 +1,30 @@
+{
+  bitcoin-node =
+    { config, pkgs, ... }:
+    {
+      deployment.targetEnv = "libvirtd";
+      deployment.libvirtd.memorySize = 8192; # megabytes
+      deployment.libvirtd.vcpu = 4; # number of cpus
+      deployment.libvirtd.headless = true;
+      deployment.libvirtd.baseImageSize = 400;
+      boot.kernelParams = [ "console=ttyS0,115200" ];
+      deployment.libvirtd.extraDevicesXML = ''
+        <serial type='pty'>
+          <target port='0'/>
+       </serial>
+        <console type='pty'>
+          <target type='serial' port='0'/>
+       </console>
+      '';
+      # Remove when fixed: https://github.com/NixOS/nixops/issues/931
+      system.activationScripts.nixops-vm-fix-931 = {
+        text = ''
+          if ls -l /nix/store | grep sudo | grep -q nogroup; then
+            mount -o remount,rw  /nix/store
+            chown -R root:nixbld /nix/store
+          fi
+        '';
+        deps = [];
+      };
+    };
+}