kubevela.github.io/docs/end-user/policies/envbinding.md

title
Multi-Environment

This documentation will introduce how to use env-binding to automate multi-stage application rollout across multiple environments.

Background

Users usually have two or more environments to deploy applications to. For example, dev environment to test the application code, and production environment to deploy applications to serve live traffic. For different environments, the deployment configuration also has some nuance.

Multi-env Application Deployment

apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: example-app
  namespace: demo
spec:
  components:
    - name: hello-world-server
      type: webservice
      properties:
        image: crccheck/hello-world
        port: 8000
      traits:
        - type: scaler
          properties:
            replicas: 1
    - name: data-worker
      type: worker
      properties:
        image: busybox
        cmd:
          - sleep
          - '1000000'
  policies:
    - name: example-multi-env-policy
      type: env-binding
      properties:
        envs:
          - name: test
            placement: # selecting the namespace (in local cluster) to deploy to
              namespaceSelector:
                name: test
            selector: # selecting which component to use
              components:
                - data-worker

          - name: staging
            placement: # selecting the cluster to deploy to
              clusterSelector:
                name: cluster-staging

          - name: prod
            placement: # selecting both namespace and cluster to deploy to
              clusterSelector:
                name: cluster-prod
              namespaceSelector:
                name: prod
            patch: # overlay patch on above components
              components:
                - name: hello-world-server
                  type: webservice
                  traits:
                    - type: scaler
                      properties:
                        replicas: 3

  workflow:
    steps:
      # deploy to test env
      - name: deploy-test
        type: deploy2env
        properties:
          policy: example-multi-env-policy
          env: test

      # deploy to staging env
      - name: deploy-staging
        type: deploy2env
        properties:
          policy: example-multi-env-policy
          env: staging

      # manual check
      - name: manual-approval 
        type: suspend

      # deploy to prod env
      - name: deploy-prod
        type: deploy2env
        properties:
          policy: example-multi-env-policy
          env: prod

We apply the Application policy-demo in the example.

Before applying this example application, you need a namespace named demo in the current cluster and namespace test in both the current cluster and the staging cluster. You need namespace prod in cluster cluster-prod as well. You can create it by executing cmd kubectl create ns <namespace>.

vela up -f app.yaml

After the Application is created, a configured Application will be created under the demo namespace.

$ kubectl get app -n demo
NAME          COMPONENT            TYPE         PHASE     HEALTHY   STATUS   AGE
example-app   hello-world-server   webservice   running                      25s

If you want to learn more about env-binding, please refer to Multi Cluster Deployment.

Appendix: Parameter List

Name	Desc	Type	Required	Default Value
envs	environment configuration	env array	true	null

env

Name	Desc	Type	Required	Default Value
name	environment name	string	true	null
patch	configure the components of the Application	patch	false	null
placement	resource scheduling strategy, choose to deploy the configured resources to the specified cluster or namespace	placement	true	null
selector	identify which components to be deployed for this environment, default to be empty which means deploying all components	selector	false	null

patch

Name	Desc	Type	Required	Default Value
components	components that need to be configured	component array	true	null

placement

Name	Desc	Type	Required	Default Value
clusterSelector	select deploy cluster by cluster name	clusterSelector	false	null
namespaceSelector	select deploy namespace by namespace name	namespaceSelector	false	null

selector

Name	Desc	Type	Required	Default Value
components	component names to be used	string array	false	null

clusterSelector

Name	Desc	Type	Required	Default Value
name	cluster name	string	false	null

namespaceSelector

Name	Desc	Type	Required	Default Value
name	namespace name	string	false	null

You need to upgrade to KubeVela v1.1.5+ to enable namespaceSelector.