Hello Dave,
When creating a VM machine, you can specify the scope of service account access for the VM instance. By default, new instances have the following scope enabled:
Therefore, if you're trying to upload a file to the Cloud Storage using 'gsutil cp' command, it will fail with the following message:
AccessDeniedException: 403 Insufficient Permission
To be able to upload a file to a bucket from your GCE VM instance, you will need to set the scope of service account of the VM instance with 'write' or 'full access' to the Cloud Storage. Please visit
this article for the steps to set this scope.
Alternatively, you can try 'gcloud auth login' command to authenticate with an account which has editor or ownership permissions to the project. Then upload the files to the Cloud Storage.
I hope this will be helpful.
Sincerely,
Kamran