When deploying a new cloud server instance, you can set user data for an instance, which is useful for startup scripts.
To set user data on a new deployment, include Base64 encoded user data in the call to Create Instance.
To update user data, use the V1 API
/v1/server/set_user_data endpoint to set Base64 encoded user data.
$ curl https://api.vultr.com/v1/server/set_user_data \ -H 'API-Key: YOUR_API_KEY' \ --data 'SUBID=YOUR_SUB_ID' \ --data 'userdata=QmUgU3VyZSBUbyBEcmluayBZb3VyIE92YWx0aW5lLgo='
To retrieve user data, use the Metadata API
/latest/user-data endpoint from the running instance. The Base64 encoded value is decoded and returned as text.
# curl http://169.254.169.254/latest/user-data Be Sure To Drink Your Ovaltine.
If you update a running instance, the
/latest/user-data Metadata endpoint will return old values until the instance is rebooted or reinstalled.