google-cloud-sdk: add passthru.updateScript (#222631)

pkgs/tools/admin/google-cloud-sdk/default.nix

···
 
   passthru = {
     inherit components withExtraComponents;
+    updateScript = ./update.sh;
   };
 
   meta = with lib; {

pkgs/tools/admin/google-cloud-sdk/update.sh

···
 #!/usr/bin/env nix-shell
-#! nix-shell -i bash -p nix
+#! nix-shell -i bash -p nix jq curl
 
 CHANNEL_URL="https://dl.google.com/dl/cloudsdk/channels/rapid"
 BASE_URL="$CHANNEL_URL/downloads/google-cloud-sdk"
 
-# Version of Google Cloud SDK from
-# https://cloud.google.com/sdk/docs/release-notes
-VERSION="426.0.0"
+PACKAGE_DIR=$(dirname -- "$0")
+
+VERSION=$(curl "https://storage.googleapis.com/storage/v1/b/cloud-sdk-release/o?delimiter=/&startOffset=google-cloud-sdk-${UPDATE_NIX_OLD_VERSION}&endOffset=google-cloud-sdk-9" | jq --raw-output '.items[-1].name | scan("\\d+\\.\\d+\\.\\d+")')
 
 function genMainSrc() {
     local url="${BASE_URL}-${VERSION}-${1}-${2}.tar.gz"
···
     echo "  };"
     echo "}"
 
-} >data.nix
+} > "${PACKAGE_DIR}/data.nix"
 
-curl "${CHANNEL_URL}/components-v${VERSION}.json" -w "\n" > components.json
+curl "${CHANNEL_URL}/components-v${VERSION}.json" -w "\n" > "${PACKAGE_DIR}/components.json"