test: add container support

test/lib/test-lib.nix

@@ -5,7 +5,7 @@ with lib;
     test = {
       noConnections = mkOption {
         type = types.bool;
-        default = true;
+        default = !config.test.container.enableWAN;
         description = ''
           Whether services should be configured to not connect to external hosts.
           This can silence some warnings while running the test in an offline environment.
@@ -19,6 +19,15 @@ with lib;
           dictionary variable 'test_data'. The data is exported via JSON.
         '';
       };
+
+      container = {
+        # Forwarded to extra-container. For descriptions, see
+        # https://github.com/erikarvstedt/extra-container/blob/master/eval-config.nix
+        addressPrefix = mkOption { default = "10.225.255"; };
+        enableWAN = mkOption { default = false; };
+        firewallAllowHost = mkOption { default = true; };
+        exposeLocalhost = mkOption { default = false; };
+      };
     };
 
     tests = mkOption {