We have a ANT based Java Swing application which currently get deployed on Solaris. We build .deb file for download and piggyback on on-premise server to download for user. Now, as we are moving to GCP, I am doing research to make it as smooth as possible. I have following concern in this regard:
The basic deployable unit in Kubernetes is a Pod. If you want to create Pod/Deployment resources, you need to specify container image you want to run and there is no way to use .deb package instead.
You can use already existing Apache Ant image e.g. webratio/ant as your base container image or create new one by defining a Dockerfile. For more information on creating and deploying containerized applications, see this tutorial.
Of course you don't have to manually build container images every time, you may use CI/CD software such as Cloud Build or GitLab CI/CD to build an image and even deploy resources on Kubernetes cluster.