What is the difference between a rebuild and a redeploy?

Build and Deploy are two distinct phases in the Upsun pipeline.

• Build has the goal of constructing a read-only file system with all of the code, in its final form, that your application needs to run.
• Deploy happens only after a successful build, and has the goal of mounting the persistent storage, starting all of the services, and providing the routing between services and the nginx entry point.

A Build can only be triggered by pushing a change in your code to Git. If your code doesn’t change, no build happens, and the read-only code file system from the previous successful Build will be used.

You can trigger a Deploy with the upsun redeploy CLI command. You can think of this command as “rebooting the server”, since all the app container will be rebooted. Services will be closed for connections in that time, and re-opened when the app container is again ready.