Add script to create and upload GCE image.

nixos/maintainers/scripts/gce/create-gce.sh

@@ -0,0 +1,14 @@
+#! /bin/sh -e
+
+export NIX_PATH=nixpkgs=../../../..
+export NIXOS_CONFIG=$(dirname $(readlink -f $0))/../../../modules/virtualisation/google-compute-image.nix
+export TIMESTAMP=$(date +%Y%m%d%H%M)
+
+nix-build '<nixpkgs/nixos>' \
+   -A config.system.build.googleComputeImage --argstr system x86_64-linux -o gce --option extra-binary-caches http://hydra.nixos.org -j 10
+
+img=$(echo gce/*.tar.gz)
+if ! gsutil ls gs://nixos/$(basename $img); then
+  gsutil cp $img gs://nixos/$(basename $img)
+fi
+gcutil addimage $(basename $img .raw.tar.gz | sed 's|\.|-|' | sed 's|_|-|') gs://nixos/$(basename $img)