VIC is a product designed to tightly integrate container workflow, lifecycle and provisioning with the vSphere SDDC. In VIC, a container is a hardware-virtualized first-class citizen on the hypervisor provisioned into a Virtual Container Host (VCH) and able to directly integrate with vSphere infrastructure capabilities, such as networking and storage features.
The architecture of VIC is designed to allow for significant modularity and flexibility and includes the following key components:
vSphere currently lacks the notion of container primitives and abstractions through which they can be manipulated. It has a rich API with bindings for various languages (Eg. govmomi) but these are all necessarily oriented around the notion of a VM.
While it would be possible to write a rudimentary VIC-like container engine by driving the vSphere APIs directly from within a daemon of some kind, the tight coupling between the low-level vSphere calls and the high-level daemon API would result in very little re-usable code and monolith that's potentially difficult to maintain. An API layer that encapsulates low-level container primitives that is both container engine and operating system agnostic would be preferable.
A secondary benefit of such an API is that it could easily be extended for compatibility with emerging standards which operate at a similar layer, such as runc.
The Port Layer is designed in such a way that the libraries can be built into static binaries or remotable services. They can be combined together into a single service endpoint or distributed for greater flexibility.