You want to modernize a standalone on-prem Java app by converting it to a container and deploying to GKE without lift-and-shift. What approach minimizes effort?

The correct approach is to use Jib to build a Docker image from the Java source, push it to Artifact Registry, deploy to GKE, and test. Jib is a build tool specifically designed for Java applications that creates optimized Docker images without requiring a Docker daemon, significantly simplifying the containerization process for Java apps and minimizing effort. This directly addresses the goal of converting a Java app to a container for GKE deployment without a full lift-and-shift of the underlying VM. Migrate for Anthos is used for migrating VMs to containers on Anthos, which is a lift-and-shift approach for the entire VM, not just the application. Exporting a VM disk and creating a Compute Engine VM from it is a lift-and-shift to IaaS, not containerization. Migrate for Compute Engine moves the VM to Compute Engine, and then using Cloud Build to containerize is a multi-step process that is more complex than directly using Jib for Java applications.