Provide a design about Pipeline Template

[JohnNiang]

What type of PR is this?

/kind design
/kind feature

What this PR does / why we need it:

1. Write a design about Pipeline Template according to Pipeline Template Design #452 .
2. Create Template API.
3. Refine Pipeline API to refer to a template.
4. Provide samples for Template and Pipeline APIs.

Which issue(s) this PR fixes:

Fixes #452

Special notes for reviewers:

Hi @kubesphere/sig-devops , this PR only contains basic definition of Template API and addition of Pipeline API, not contain any reconciliation logic here. The most important thing is the design of Pipeline Template.

Does this PR introduce a user-facing change??

Improve the Pipeline templates which can load from API

[codecov]

Codecov Report

Merging #453 (4bf1331) into master (6cb96cf) will decrease coverage by 0.04%.
The diff coverage is 14.28%.

@@            Coverage Diff             @@
##           master     #453      +/-   ##
==========================================
- Coverage   76.98%   76.94%   -0.05%     
==========================================
  Files         111      113       +2     
  Lines       22094    22101       +7     
==========================================
- Hits        17009    17005       -4     
- Misses       4909     4919      +10     
- Partials      176      177       +1     

Flag	Coverage Δ
unittests	76.94% <14.28%> (-0.05%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
controllers/template_controller.go	0.00% <0.00%> (ø)
pkg/api/devops/v1alpha1/groupversion_info.go	100.00% <ø> (ø)
pkg/api/devops/v1alpha1/template_types.go	100.00% <100.00%> (ø)
...trollers/devopsproject/devopsproject_controller.go	40.62% <0.00%> (-2.61%)	⬇️

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[JohnNiang]

#453 (comment)

Hi @kubesphere/sig-devops , I found that multi-version API might be very complex. We need to create a brand new Pipeline API event if we only add template referent. Meanwhile, we also need to create a Webhook to convert CR between our versions.

I'd prefer to revert Pipeline API enhancement now and fire another PR to solve those problems. What do you reckon?

[LinuxSuRen]

I'd prefer to revert Pipeline API enhancement now and fire another PR to solve those problems. What do you reckon?

Agree!

[JohnNiang]

Hi @kubesphere/sig-devops , I have reverted Pipeline API improvment according to #453 (comment), please take some moment to have a look.

[LinuxSuRen]

/label tide/merge-method-squash
/lgtm
/approve

[ks-ci-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: JohnNiang, LinuxSuRen

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