We are developing a microservice based system that is orchestrated using Kubernetes. Part of our use case is supplying our clients an On-Premise installation where they receive an Image (VMDK / QCOW2) with all the system deployed.
One of our main challenges is handling the update process of such system, currently the plan is to have an API endpoint that will receive an encrypted and signed package that will contain all the images and a certain update shell script. The API endpoint will start an asynchronous process that will extract the images and execute the shell script that eventually should call the Kubernetes to update all the images with the new code.
The question is where this API endpoint should be defined?
- Be in a special "Maintenance" service that will be outside of the Kubernetes and control it, this service will be updated last in case it's code should be also updated.
- Be part of one of the microservices containers that run inside Kubernetes - but then this image can be part of the updated images so any API that should return the update status can be un-available
What is the common way to export an interface to System Update or System Deployment wizard processes?
Thanks!