mastodon: add elasticsearch

hosts/mastodon/default.nix

@@ -14,8 +14,14 @@
   };
   c3d2.hq.statistics.enable = true;
   system.stateVersion = "22.11";
-
+  nixpkgs.config.allowUnfreePredicate = pkg:
+    lib.getName pkg == "elasticsearch";
+  
   services.postgresql.enable = true;
+  services.elasticsearch = {
+    enable = true;
+    package = pkgs.elasticsearch7;
+  };
   services.mastodon = {
     enable = true;
     localDomain = "c3d2.social";
@@ -28,6 +34,7 @@
     #     echo "${secrets.email.smtp-password}" > $out
     #   ''}";
 
+    elasticsearch.host = "127.0.0.1";
 
     extraConfig = {
       ALTERNATE_DOMAINS = lib.concatStringsSep "," [