feat(lang): Support data and code integration in envd-server runner

[aseaday]

Descrption

I study the design docment and #303. In a team work environment, there is no doubt that model, exp log and dataset would be allso a neccessary part in a work env setting up. There some tools and project aimmed to solve it such as DVC.

This issue is for discussion about:

• Should we support stroage for data sharing?
• What is the best way to achieve it?

---

Message from the maintainers:

Love this enhancement proposal? Give it a 👍. We prioritise the proposals with the most 👍.

[gaocegege]

Thanks for raising the discussions! There are some options for us:

• Integrate with DVC. But DVC is not a de-facto standard now and it also has some problems.
• Design the primitives in build.envd to declare expected locations of datasets/model/logs.

def build()
  config.model(location="xx", from="https://xx.savedmodel"

[gaocegege]

Possible design:

runtime.docker.mount and other docker-specific funcs will be ignored in kubernetes context. runtime.kubernetes.mount() should create/use the corresponding PV/PVC in the backend pod.

runtime.kubernetes.mount("")