How to deploy after stopping the previous one version?

Questions / Help
1

How to deploy a new version/release before full stopping the previous one?

My service can only make one connection, so I need to stop the previous one before deploying the new release. Otherwise, more than one instance will not make it work.

2

This can be done by setting the deployment strategy to rolling.

e.g in fly.toml:

[deploy]
  strategy = "rolling"