lxc-download.in / Document keyserver change in help

templates/lxc-download.in

@@ -204,7 +204,7 @@ Optional arguments:
 [ --variant <variant> ]: Variant of the image (default: "default")
 [ --server <server> ]: Image server (default: "images.linuxcontainers.org")
 [ --keyid <keyid> ]: GPG keyid (default: 0x...)
-[ --keyserver <keyserver> ]: GPG keyserver to use
+[ --keyserver <keyserver> ]: GPG keyserver to use. Environment variable: DOWNLOAD_KEYSERVER
 [ --no-validate ]: Disable GPG validation (not recommended)
 [ --flush-cache ]: Flush the local copy (if present)
 [ --force-cache ]: Force the use of the local copy even if expired
@@ -215,6 +215,11 @@ LXC internal arguments (do not pass manually!):
 [ --rootfs <rootfs> ]: The path to the container's rootfs
 [ --mapped-uid <map> ]: A uid map (user namespaces)
 [ --mapped-gid <map> ]: A gid map (user namespaces)
+
+Environment Variables:
+DOWNLOAD_KEYSERVER : The URL of the key server to use, instead of the default.
+                     Can be further overridden by using optional argument --keyserver
+
 EOF
     return 0
 }