[WIP] Adds openfaas operator addon

[afzalbin64]

Description of your changes

Fixes #5056

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 @afzalbin64, is this pr still in progress?

[afzal442]

Hello @wangyikewxgm! You can review it up till what I did. Also, LMK how I can find resources to write its template for openfaas operator definitions and generate its example. Thanks. Although I found this doc, it is limited one. 😉

[afzal442]

Hi @wangyikewxgm ! I just found this docs where I got to know how to go further. https://kubevela.io/docs/platform-engineers/components/custom-component. I had been waiting for you. Thanks

eg vela def init stateless -t component --template-yaml ./stateless.yaml -o stateless.cue

[wangyikewxgm]

I apologize for the delayed reply. First, you can review the primary CRD in this Helm chart and manually create it by writing a native CRD YAML file. Next, you can follow this documentation to write a CUE template in the definition and generate a CRD using KubeVela.

Also, I highly recommend taking a look at this informative guide on how to create a workload in OpenFaaS, which can be found here. By gaining a deeper understanding of OpenFaaS, you can then create the add-on.

[afzal442]

Hi there, if I try to use type helm, would it be sufficient to use it for Function custom resource?
the updated template.yaml would be like

apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: openfaas-operator
  namespace: openfaas-sys
spec:
  components:
  - name: openfaas-required
      type: k8s-objects # Set to k8s-objects
      properties:
        objects:
          - apiVersion: v1
            kind: Namespace
            metadata:
              name: openfaas
          - apiVersion: v1
            kind: Namespace
            metadata:
              name: openfaas-fn
    - name: openfaas-operator
      type: helm
      properties:
        chart: openfaas
        version: 0.16.4
        repoType: helm
        url: https://openfaas.github.io/faas-netes
        releaseName: my-openfaas
        targetNamespace: openfaas
        values:
            ingress.enabled: true

Ref: https://github.com/openfaas/faas-netes/blob/master/chart/openfaas/README.md
https://www.openfaas.com/blog/howto-package-functions-with-helm/
cc @barnettZQG