Kubernetes component parser

[yangcao77]

Which area this feature is related to?

/area library

Which functionality do you think we should add?

Why is this needed? Is your feature request related to a problem?
after outerloop scenario has been supported in devfile 2.2.0, Kubernetes component will be frequently used for deploy commands.
consumers like HAS an ODC will need to fetch information from Kubernetes components and display to user.

Detailed description:
Library should be able to parse, write and validate Kubernetes components

Describe the solution you'd like

• Library should be able to parse Kubernetes components (within devfile & separate file)
• Library should be able to validate Kubernetes components
• Library should be able to update & write to Kubernetes components (within devfile & separate file)

Describe alternatives you've considered

Additional context

[amisevsk]

This issue seems like it's preparing to duplicate existing functionality within Kubernetes libraries -- are we sure want to build and maintain this?

[yangcao77]

This item needs further investigation, but we need an extra layer to read from & write to kubernetes definition in devfile. If Kubernetes libraries already have exactly what we need, then the library should import & use Kubernetes libraries, and add additional helper functions to fulfill our needs.

[yangcao77]

been done in devfile/library#137
instead of creating a complete parser for kubernetes component, we decided to provider a helper function for consumers to parse the kubernetes yaml. only deployment, service, route and ingress is being extracted out with the helper function. for any other k8s resources, consumers can do the extraction on demand.