add filename option

formats/hyperv.nix

@@ -5,4 +5,5 @@
   ];
 
   formatAttr = "hypervImage";
+  filename = "*.vhdx";
 }

formats/install-iso-hyperv.nix

@@ -9,4 +9,5 @@
   virtualisation.hypervGuest.enable = true;
 
   formatAttr = "isoImage";
+  filename = "*.iso";
 }

formats/install-iso.nix

@@ -12,4 +12,5 @@
   systemd.services.sshd.wantedBy = lib.mkForce [ "multi-user.target" ];
 
   formatAttr = "isoImage";
+  filename = "*.iso";
 }

formats/iso.nix

@@ -11,4 +11,5 @@
   isoImage.makeUsbBootable = true;
 
   formatAttr = "isoImage";
+  filename = "*.iso";
 }

formats/kexec.nix

@@ -55,4 +55,5 @@ in {
   networking.hostName = lib.mkDefault "kexec";
 
   formatAttr = "kexec_tarball";
+  filename = "*/tarball/*.tar.xz";
 }

formats/lxc-metadata.nix

@@ -13,6 +13,8 @@
       target = "/metadata.yaml";
     }];
   };
+
   formatAttr = "metadata";
+  filename = "*/tarball/*.tar.xz";
 }
 

formats/lxc.nix

@@ -19,4 +19,5 @@ in {
   });
 
   formatAttr = "tarball";
+  filename = "*/tarball/*.tar.xz";
 }

formats/raw.nix

@@ -19,4 +19,5 @@
   };
 
   formatAttr = "raw";
+  filename = "*.img";
 }

formats/virtualbox.nix

@@ -5,4 +5,5 @@
   ];
 
   formatAttr = "virtualBoxOVA";
+  filename = "*.ova";
 }

nixos-generate

@@ -121,12 +121,13 @@ if [[ -n $cores ]]; then
 fi
 
 formatAttr=$(nix-instantiate "${nix_args[@]}" --eval --json -A config.formatAttr | jq -r .)
+filename=$(nix-instantiate "${nix_args[@]}" --eval --json -A config.filename | jq -r .)
 
 out=$(nix-build "${nix_args[@]}" --no-out-link -A "config.system.build.$formatAttr")
 
 if [[ -z $run ]]; then
   # show the first file, ignoring nix-support
-  find "$out" -path "$out/nix-support" -prune -o -type f -print -quit
+  find "$out" -wholename "$filename" -type f -print -quit
 else
   runner=$(find "$out"/bin -type l -print -quit)
   exec "$runner"

nixos-generate.nix

@@ -6,6 +6,11 @@
 let
   module = { lib, ... }: {
     options = {
+      filename = lib.mkOption {
+        type = lib.types.str;
+        description = "Declare the path of the wanted file in the output directory";
+        default = "*";
+      };
       formatAttr = lib.mkOption {
         type = lib.types.str;
         description = "Declare the default attribute to build";