nixos/gnome-keyring: add SSH support by exporting SSH_AUTH_SOCK

nixos/modules/security/ssh-agent.nix

@@ -0,0 +1,26 @@
+{ config, pkgs, lib, ... }:
+let
+  cfg = config.security.SSHAgent;
+in {
+
+  options = {
+    security.SSHAgent = {
+      socket = lib.mkOption {
+        type = lib.types.nullOr lib.types.str;
+        default = null;
+        description = "The path to the SSH agent socket";
+      };
+    };
+  };
+
+
+  config = lib.mkIf cfg.socket != null {
+    environment.extraInit =   ''
+      if [ -z "$SSH_AUTH_SOCK" -a -n "$XDG_RUNTIME_DIR" ]; then
+        export SSH_AUTH_SOCK=${cfg.socket}
+      fi
+    '';
+  };
+
+
+}

nixos/modules/services/desktops/gnome/gnome-keyring.nix

@@ -1,7 +1,9 @@
 # GNOME Keyring daemon.
 
 { config, pkgs, lib, ... }:
-
+let
+  cfg = config.services.gnome.gnome-keyring;
+in
 {
 
   meta = {
@@ -24,14 +26,16 @@
         '';
       };
 
+      SSHSupport.enable = lib.mkEnableOption "SSH agent support for GNOME Keyring by setting the SSH_AUTH_SOCK environment variable";
+
     };
 
   };
 
 
   ###### implementation
 
-  config = lib.mkIf config.services.gnome.gnome-keyring.enable {
+  config = lib.mkIf cfg.enable {
 
     environment.systemPackages = [ pkgs.gnome.gnome-keyring ];
 
@@ -48,6 +52,8 @@
       source = "${pkgs.gnome.gnome-keyring}/bin/gnome-keyring-daemon";
     };
 
+    security.SSHAgent.socket = lib.mkIf cfg.SSHSupport.enable "$XDG_RUNTIME_DIR/keyring/ssh";  
+
   };
 
 }