Borg, Omega, Kubernetes: Lessons learned from container management over a decade
The thing I'm still struggling to wrap my head around with kubernetes (and docker in general) is the management of data persistence.If I have a pod of containers everything I read seems to say that containers need to be 'stateless' and if you're running kubernetes, will likely also be transient based on the system load & scale.So if any container in a pod could go away or be spun up at any time, if it could live on any virtual machine in a cluster of physical machines...where do you keep the physical database file so that it is accessible to all different instances? How do the multiple instances access it at the same time? Generally, how does the database layer "work" in container land?It's the only piece that I really struggle to understand.