post-build-hook: Make post build hook async

build01/cache.nix

@@ -4,13 +4,46 @@ let
 
   postBuildHook = pkgs.writeScript "post-build-hook.sh" ''
     #!${pkgs.runtimeShell}
+    export PATH=$PATH:${pkgs.nix}/bin
     exec ${pkgs.cachix}/bin/cachix -c /var/lib/post-build-hook/nix-community-cachix.dhall push nix-community $OUT_PATHS
   '';
 
+  sockPath = "/run/post-build-hook.sock";
+
+  queueBuildHook = pkgs.writeScript "post-build-hook.sh" ''
+    ${pkgs.queued-build-hook}/bin/queued-build-hook queue --socket ${sockPath}
+  '';
+
+  sources = import ../nix/sources.nix;
+
 in {
 
+  nixpkgs.overlays = [
+    (self: super: {
+      queued-build-hook = (import sources.queued-build-hook {});
+    })
+  ];
+
+  systemd.sockets.queued-build-hook = {
+    description = "Post-build-hook socket";
+    wantedBy = [ "sockets.target" ];
+    socketConfig = {
+      ListenStream = sockPath;
+      SocketUser = "root";
+      SocketMode = "0600";
+    };
+  };
+
+  systemd.services.queued-build-hook = {
+    description = "Post-build-hook service";
+    wantedBy = [ "multi-user.target" ];
+    after = [ "network.target" "queued-build-hook.socket" ];
+    requires = [ "queued-build-hook.socket" ];
+    serviceConfig.ExecStart = "${pkgs.queued-build-hook}/bin/queued-build-hook daemon --retry-interval 30 --hook ${postBuildHook}";
+  };
+
   nix.extraOptions = ''
-    post-build-hook = ${postBuildHook}
+    post-build-hook = ${queueBuildHook}
   '';
 
 }

nix/sources.json

@@ -47,6 +47,18 @@
         "url": "https://github.com/jonringer/nixpkgs-update-pypi-releases/archive/cf72f9a94b0ccc306c025eba222a70456378433d.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
+    "queued-build-hook": {
+        "branch": "master",
+        "description": "Queue and retry Nix post-build-hook",
+        "homepage": null,
+        "owner": "nix-community",
+        "repo": "queued-build-hook",
+        "rev": "24882efb9b61fc39273c6421b914d45701f85cb8",
+        "sha256": "0q1bvbsny5xs5wnzn17zwgigb3xkrjxy7vm1yxk24kam1vcwymv9",
+        "type": "tarball",
+        "url": "https://github.com/nix-community/queued-build-hook/archive/24882efb9b61fc39273c6421b914d45701f85cb8.tar.gz",
+        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
+    },
     "simple-hydra": {
         "branch": "master",
         "description": "A simple module for enabling Hydra",