Google Cloud Service CORS Configuration in the Rails Console

gcs-cors.rb

# In order to use Rails Active Storage Direct Upload to a cloud service, e.g., using Rails 
# Action Text rich text editor image upload button, the cloud service will need CORS
# configured. The GCS CORS doc at https://cloud.google.com/storage/docs/configuring-cors
# describes 3 ways of doing it. I wanted to use the Ruby code method, since I already had
# GCS configured for my app and could avoid configuring some other utility. The key was
# getting a handle on a client from my rails app. So, assuming you have already uploaded
# something via your app (not via direct upload):
client = ActiveStorage::Blob.last.service.send :client
bucket = client.buckets.first
bucket.update do |bucket|
  bucket.cors do |cors|
    cors.add_rule ["http://localhost:3000"], "*", headers: ["Origin", "Content-Type", "Content-MD5", "Content-Disposition"], max_age: 3600
  end
end