Add HTTPS nix cache to hydra

servers/hydra.nix

@@ -1,6 +1,7 @@
-{ ... }:
+{ lib, ... }:
 let
-  domain = "ci.sinerva.eu";
+  hydra_domain = "ci.sinerva.eu";
+  cache_domain = "cache.sinerva.eu";
 in
 {
   imports = [
@@ -13,7 +14,7 @@ in
   services = {
     hydra = {
       enable = true;
-      hydraURL = "https://${domain}";
+      hydraURL = "https://${hydra_domain}";
       listenHost = "localhost";
       notificationSender = "hydra@sinerva.eu";
       port = 8080;
@@ -25,8 +26,20 @@ in
       '';
     };
 
-    nginx.virtualHosts.${domain}.locations."/" = {
-      proxyPass = "http://localhost:8080";
+    nix-serve = {
+      enable = true;
+      bindAddress = "::1";
+      port = 8081;
+      secretKeyFile = "/persist/secrets/priv_cache_key";
+    };
+
+    nginx.virtualHosts = {
+      ${hydra_domain}.locations."/" = {
+        proxyPass = "http://localhost:8080";
+      };
+      ${cache_domain}.locations."/" = {
+        proxyPass = "http://localhost:8081";
+      };
     };
   };
 
@@ -54,5 +67,11 @@ in
         maxJobs = 6;
       }
     ];
+
+    gc = {
+      options = lib.mkForce "--delete-older-than 1d";
+      dates = lib.mkForce "hourly";
+      randomizedDelaySec = lib.mkForce "0";
+    };
   };
 }