Add nix signing key to hydra

Signed-off-by: magic_rb <magic_rb@redalder.org>

nixng/containers/hydra/hydra.nix

@@ -1,13 +1,19 @@
-{ makeSystem
-, nixpkgs
-, hydra
+{
+  makeSystem,
+  nixpkgs,
+  hydra,
 }:
 makeSystem {
   system = "x86_64-linux";
   name = "nixng-hydra";
   inherit nixpkgs;
-  config = { pkgs, config, lib, nglib, ... }:
-    {
+  config = {
+    pkgs,
+    config,
+    lib,
+    nglib,
+    ...
+  }: {
     config = {
       dumb-init = {
         enable = true;
@@ -35,6 +41,7 @@ makeSystem {
 
           builders-use-substitutes = true;
           builders = "@/etc/nix/machines";
+          secret-key-files = "/secrets/nix-key.private";
           extra-platforms = ["i686-linux" "aarch64-linux"];
         };
       };
@@ -72,19 +79,19 @@ makeSystem {
       };
 
       services.crond.crontabs.autogc = {
-          jobs =
-            let
-              storegc = pkgs.writeShellScript "storegc"
+        jobs = let
+          storegc =
+            pkgs.writeShellScript "storegc"
             ''
               nix-collect-garbage -d
             '';
-            in
-              [
+        in [
           "0 4 * * * ${storegc}"
         ];
       };
 
-        init.services.nix-daemon.environment.PATH = with pkgs;  lib.makeBinPath [
+      init.services.nix-daemon.environment.PATH = with pkgs;
+        lib.makeBinPath [
           utillinux
           runit
           busybox
@@ -92,8 +99,7 @@ makeSystem {
           gzip
         ];
 
-        system.activation =
-          let
+      system.activation = let
         machines = pkgs.writeText "machines" ''
           eu.nixbuild.net x86_64-linux,aarch64-linux,i686-linux - 100 5 benchmark,big-parallel
           localhost x86_64-linux - 2 1 benchmark,big-parallel,kvm,nixos-test,local
@@ -128,8 +134,7 @@ makeSystem {
           chmod 600 /ssh-key
           chown hydra-queue-runner:root /ssh-key
         '';
-          in
-            {
+      in {
         inherit ssh-key ssh nix-machines;
       };
     };

terranix/containers/hydra/job.hcl

@@ -158,6 +158,14 @@ EOF
         destination = "secrets/pgpass-queue-runner"
         perms = "400"
       }
+
+      template {
+        data = <<EOF
+{{ with secret "kv/data/cluster/hydra" }}{{ .Data.data.nix_signing_key }}{{ end }}
+EOF
+        destination = "secrets/nix-key.private"
+        perms = "400"
+      }
     }
 
     task "postgresql" {