Add rfc for pipectl init

[ouchi2501]

What this PR does / why we need it:

Add init to the pipectl command.
See below for Discussion.
#4635

Which issue(s) this PR fixes:

Fixes #

Does this PR introduce a user-facing change?:

• How are users affected by this change:
• Is this breaking change:
• How to migrate (if breaking change):

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (2501848) 30.84% compared to head (a0824bd) 30.82%.

❗ Current head a0824bd differs from pull request most recent head 29d31c5. Consider uploading reports for the commit 29d31c5 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4672      +/-   ##
==========================================
- Coverage   30.84%   30.82%   -0.02%     
==========================================
  Files         221      221              
  Lines       25993    25935      -58     
==========================================
- Hits         8018     7995      -23     
+ Misses      17325    17290      -35     
  Partials      650      650              

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[kentakozuka]

Is it only app.pipecd.yaml that the first step(1. Create a configuration file from scratch) creates?

[ouchi2501]

#4672 (comment)
@kentakozuka
Yes, Only app.pipecd.yaml

[kentakozuka]

As you mentions here, would it be better to generate app.pipecd.yaml from applications's configs?
I input configs in example and PipeCD's GPT output is the following. Looks not bad. WDYT?

apiVersion: pipecd.dev/v1beta1
kind: KubernetesApp
spec:
  input:
    # Specify the namespace if needed; otherwise, PipeCD deploys to the default namespace
    namespace: default
    kubernetes:
      manifests:
        - deployment.yaml
        - service.yaml
  pipeline:
    stages:
      # The primary deployment rollout
      - name: K8S_PRIMARY_ROLLOUT
      # The stage for manual approval (if needed)
      - name: WAIT_APPROVAL
      # The canary deployment rollout
      - name: K8S_CANARY_ROLLOUT
        with:
          replicas: 50% # Adjust the percentage as required
      # The cleanup stage for the canary deployment
      - name: K8S_CANARY_CLEAN
  trafficRouting:
    method: pod
    kubernetes:
      primary:
        labels:
          pipecd.dev/variant: primary
      canary:
        labels:
          pipecd.dev/variant: canary

Or applications all configs are created by pipectl based on the answers 🤔

[ouchi2501]

I think it should have both features.
As for pipectl init, I think it would be less confusing for users if it was created as a general interactive init command rather than relying solely on GPT from the start!
However, I also think the ability to create a config from the application config through GPT would be very nice!
I think it would be nice to have the ability to create a config from the application config via GPT as an option for pipectl init!

[kentakozuka]

@ouchi2501 Sounds very cool! Let's stick with your plan :)