Remove NixOS 19.09 and make menu more dynamic

19.09 is EOL so this drops it from menu. Makes
changes to the menu to allow it to be more dynamic
with endpoint changes

endpoints.yml

@@ -1314,14 +1314,6 @@ endpoints:
     - netboot.ipxe
     os: nixos
     version: '20.03'
-  nixos-19.09:
-    path: /asset-mirror/releases/download/122708153-fbcf280f/
-    files:
-    - bzImage
-    - initrd
-    - netboot.ipxe
-    os: nixos
-    version: '19.09'
   backbox-7-default-squash:
     path: /ubuntu-squash/releases/download/7-8df8aaac/
     files:

roles/netbootxyz/templates/menu/nixos.ipxe.j2

@@ -6,11 +6,18 @@
 set os {{ releases.nixos.name }}
 menu ${os}
 item --gap Official Releases
-item 20.03 ${space} ${os} 20.03
-item 19.09 ${space} ${os} 19.09
+{% for key, value in endpoints.items() | sort %}
+{% if value.os == "nixos" %}
+item {{ value.version }} ${space} ${os} {{ value.version }}
+{% endif %}
+{% endfor %}
 choose version || goto nixos_exit
-iseq ${version} 20.03 && set link ${live_endpoint}{{ endpoints["nixos-20.03"].path }}netboot.ipxe ||
-iseq ${version} 19.09 && set link ${live_endpoint}{{ endpoints["nixos-19.09"].path }}netboot.ipxe ||
+
+{% for key, value in endpoints.items() | sort %}
+{% if value.os == "nixos" %}
+iseq ${version} {{ value.version }} set link ${live_endpoint}{{ value.path }}netboot.ipxe ||
+{% endif %}
+{% endfor %}
 imgfree
 chain ${link}
 goto nixos_exit