How to update an instance metadata in GCP.
gcloud compute instances add-metadata instance-name \ --metadata key-name=value \ --project your-project-id \ --zone us-central1-a |
In this example, we are adding enable-oslogin=TRUE.
gcloud compute instances add-metadata instance-name \ --metadata enable-oslogin=TRUE \ --project your-project-id \ --zone us-central1-a |