[Addon #603] Add Apache Spark as a experimental addon

[yanghua]

Signed-off-by: yanghua yanghua1127@gmail.com

Description of your changes

How has this code been tested?

Checklist

I have:

• Title of the PR starts with type (e.g. [Addon] , [example] or [Doc]).
• Updated/Added any relevant documentation and examples.
• New addon should be put in experimental.
• Update addon should modify the version in metadata.yaml to generate a new version.

Verified Addon promotion rules

If this pr wants to promote an experimental addon to verified, you must check whether meet these conditions too:

• This addon must be tested by addon's e2e-test to guarantee this addon can be enabled successfully.
• This addon must have some basic but necessary information.
  • An accessible icon url and source url defined in addon's metadata.yaml.
  • A detail introduction include a basic example about how to use and what's the benefit of this addon in README.md.
  • Also provide an introduction in KubeVela documentation.
  • It's more likely to be accepted if useful examples provided in example dir.

[wangyikewxgm]

Hi @yanghua , is this pr still in progress.

[yanghua]

Hi @yanghua , is this pr still in progress.

Yes, considering Spark is a big engine and the Spark on Kubernetes operator provides a very comprehensive ability. I am still improving it and verifying it in our local env. Thanks for your patience.

[yanghua]

Hi @wangyikewxgm I will provide a basic version of this addon. More advanced features would be iterated in the future. WDYT?

[wangyikewxgm]

Hi @wangyikewxgm I will provide a basic version of this addon. More advanced features would be iterated in the future. WDYT?

OK，thanks for your contribution.

[wangyikewxgm]

LGTM. Thank you for your contribution. Based on the successful enabling of this add-on and its clear and explicit introduction, I believe this PR is ready to be merged. In the future, we can make some optimizations for this addon, such as adding a topology rule configuration.

[yanghua]

LGTM. Thank you for your contribution. Based on the successful enabling of this add-on and its clear and explicit introduction, I believe this PR is ready to be merged. In the future, we can make some optimizations for this add-on, such as adding a topology rule configuration.

Good suggestion, will iterate more advanced feature soon.

[yanghua]

@wonderflow Any input about this PR?

[wonderflow]

generally LGTM, ping @wangyikewxgm it would be better if we don't rely on kubectl in the readme of addons.