add EnvBinding Controller for Multi cluster deploy and Configuration Management

[yangsoon]

What this PR does / why we need it:

this PR add EnvBinding Controller for Multi cluster deploy and Configuration Management.

Now EnvBinding Controller default support use OCM as multi-cluster engine. In the future, we will support other multi-cluster solutions such as karmada etc.

Suppose you have deploy KubeVela in your controller-plane cluster and have use OCM to register multiple ManagedCluster.

You have a ManagedCluster called kind-cluster1

$ kubectl get managedclusters.cluster.open-cluster-management.io
NAME            HUB ACCEPTED   MANAGED CLUSTER URLS             JOINED   AVAILABLE   AGE
kind-cluster1   true           https://hub-control-plane:6443   True     Unknown     10h

And have labeled ManagedCluster with purpose: test.

# kubectl get managedclusters.cluster.open-cluster-management.io kind-cluster1 -o yaml
apiVersion: cluster.open-cluster-management.io/v1
kind: ManagedCluster
metadata:
  finalizers:
  - cluster.open-cluster-management.io/api-resource-cleanup
  generation: 2
  labels:

    purpose: test

  name: kind-cluster1
spec:
  hubAcceptsClient: true
  leaseDurationSeconds: 60
  managedClusterClientConfigs:
  - caBundle: XXX
    url: https://hub-control-plane:6443
status:
  allocatable:
    cpu: "4"
    memory: 7962Mi
  capacity:
    cpu: "4"
    memory: 7962Mi
  conditions:
  - lastTransitionTime: "2021-07-26T01:23:39Z"
    message: Accepted by hub cluster admin
    reason: HubClusterAdminAccepted
    status: "True"
    type: HubAcceptedManagedCluster
  version:
    kubernetes: v1.20.2

Then you can define an EnvBinding object as follow:

apiVersion: core.oam.dev/v1alpha1
kind: EnvBinding
metadata:
  name: test-env
  namespace: default
spec:
  engine: ocm
  # This is the app template you want to configure
  appTemplate:
    apiVersion: core.oam.dev/v1beta1
    kind: Application
    metadata:
      name: test-app
      namespace: default
    spec:
      components:
        - name: myweb
          type: worker
          properties:
            image: busybox
            cmd: ["sleep", "10000"]
  envs:
    - name: env1
      # you can patch properties for application in different envs
      patch:
        components:
          - name: myweb
            type: worker
            properties:
              image: busybox
              cmd: ["sleep", "20000"]
      #  select cluster you want app be deployed to
      placement:
        clusterSelector:
          # you can select by label
          labels:
            purpose: test
          # you can also specify cluster name directly
          #name: kind-cluster1

The EnvBinding Controller will store the manifest of different envs to ConfigMap.

apiVersion: v1
data:
  env1: |
    apiVersion: work.open-cluster-management.io/v1
    kind: ManifestWork
    metadata:
      name: test-app-env1
      namespace: kind-cluster1
    spec:
      workload:
        manifests:
        - apiVersion: apps/v1
          kind: Deployment
          metadata:
            labels:
              app.oam.dev/appRevision: ""
              app.oam.dev/component: myweb
              app.oam.dev/name: test-app
              workload.oam.dev/type: worker
            name: myweb
            namespace: default
          spec:
            selector:
              matchLabels:
                app.oam.dev/component: myweb
            template:
              metadata:
                labels:
                  app.oam.dev/component: myweb
              spec:
                containers:
                - command:
                  - sleep
                  - "20000"
                  image: busybox
                  name: myweb
        - apiVersion: v1
          kind: Pod
          metadata:
            labels:
              app.oam.dev/appRevision: ""
              app.oam.dev/component: myweb
              app.oam.dev/name: test-app
              trait.oam.dev/resource: ingress
              trait.oam.dev/type: AuxiliaryWorkload
            name: test
            namespace: default
          spec:
            containers:
            - command:
              - sleep
              - "20000"
              image: busybox
              name: myweb
kind: ConfigMap
metadata:
  name: test-env
  namespace: default

Which issue(s) this PR fixes:

Fixes #1881

Special notes for your reviewer:

• add envbinding controller
• add test

[codecov]

Codecov Report

Merging #1968 (f14b27e) into master (4481e76) will increase coverage by 0.13%.
The diff coverage is 61.97%.

@@            Coverage Diff             @@
##           master    #1968      +/-   ##
==========================================
+ Coverage   63.78%   63.91%   +0.13%     
==========================================
  Files         152      158       +6     
  Lines       14512    14892     +380     
==========================================
+ Hits         9256     9518     +262     
- Misses       4336     4412      +76     
- Partials      920      962      +42     

Flag	Coverage Δ
e2e-rollout-tests	28.88% <10.32%> (-0.47%)	⬇️
e2etests	38.19% <61.97%> (+0.88%)	⬆️
unittests	59.10% <7.69%> (-0.13%)	⬇️

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

Impacted Files	Coverage Δ
apis/core.oam.dev/v1alpha2/conversion.go	44.44% <0.00%> (ø)
apis/core.oam.dev/v1beta1/application_types.go	20.00% <ø> (ø)
apis/core.oam.dev/v1beta1/zz_generated.deepcopy.go	41.37% <ø> (+1.02%)	⬆️
pkg/appfile/parser.go	73.33% <ø> (ø)
pkg/oam/util/helper.go	79.00% <33.33%> (-0.95%)	⬇️
pkg/appfile/helm/helm.go	59.45% <50.00%> (-2.55%)	⬇️
...m.dev/v1alpha2/envbinding/envbinding_controller.go	52.00% <52.00%> (ø)
apis/core.oam.dev/common/zz_generated.deepcopy.go	37.95% <53.06%> (+3.77%)	⬆️
...pis/core.oam.dev/v1alpha1/zz_generated.deepcopy.go	53.08% <53.08%> (ø)
...roller/core.oam.dev/v1alpha2/envbinding/binding.go	62.87% <62.87%> (ø)
... and 23 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 4481e76...f14b27e. Read the comment docs.

[wonderflow]

good job