Execute pipeline step in just-built image?

I’m trying to set up a pipeline to build an image, use that image to execute two commands (one to migrate the DB, one to update consul configs), deploy the image to ECS, wait for the ECS to be stable with health checks passing for all container instances, and then finally release the now-stable ECS deployment.

Clearly, in a normal “up”, deploy knows how to determine the image to deploy and presumably gets that from the build step. How can I set the image_url to the image waypoint just finished building?

For that matter, can I set a registry to be used for the image pull? Since the build is pushing to a private ECR.