kubevela.github.io/docs/end-user/cloud-resources.md

title
Provision and Consume Cloud Resources by Crossplane

⚠️ This section requires your platform builder has already installed the cloud resources related capabilities.

Provision and consume cloud resource in a single application v1 (one cloud resource)

Check the parameters of cloud resource component:

$ kubectl vela show alibaba-rds

# Properties
+---------------+------------------------------------------------+--------+----------+--------------------+
|     NAME      |                  DESCRIPTION                   |  TYPE  | REQUIRED |      DEFAULT       |
+---------------+------------------------------------------------+--------+----------+--------------------+
| engine        | RDS engine                                     | string | true     | mysql              |
| engineVersion | The version of RDS engine                      | string | true     |                8.0 |
| instanceClass | The instance class for the RDS                 | string | true     | rds.mysql.c1.large |
| username      | RDS username                                   | string | true     |                    |
| secretName    | Secret name which RDS connection will write to | string | true     |                    |
+---------------+------------------------------------------------+--------+----------+--------------------+

Use the service binding trait to bind cloud resources into workload as ENV.

Create an application with a cloud resource provisioning component and a consuming component as below.

apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: webapp
spec:
  components:
    - name: express-server
      type: webservice
      properties:
        image: zzxwill/flask-web-application:v0.3.1-crossplane
        ports: 80
      traits:
        - type: service-binding
          properties:
            envMappings:
              # environments refer to db-conn secret
              DB_PASSWORD:
                secret: db-conn
                key: password                                     # 1) If the env name is different from secret key, secret key has to be set.
              endpoint:
                secret: db-conn                                   # 2) If the env name is the same as the secret key, secret key can be omitted.
              username:
                secret: db-conn

    - name: sample-db
      type: alibaba-rds
      properties:
        name: sample-db
        engine: mysql
        engineVersion: "8.0"
        instanceClass: rds.mysql.c1.large
        username: oamtest
        secretName: db-conn

Apply it and verify the application.

$ kubectl get application
NAME     AGE
webapp   46m

$ kubectl port-forward deployment/express-server 80:80
Forwarding from 127.0.0.1:80 -> 80
Forwarding from [::1]:80 -> 80
Handling connection for 80
Handling connection for 80

Provision and consume cloud resource in a single application v2 (two cloud resources)

Based on the section Provisioning and consuming cloud resource in a single application v1 (one cloud resource),

Update the application to also consume cloud resource OSS.

apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: webapp
spec:
  components:
    - name: express-server
      type: webservice
      properties:
        image: zzxwill/flask-web-application:v0.3.1-crossplane
        ports: 80
      traits:
        - type: service-binding
          properties:
            envMappings:
              # environments refer to db-conn secret
              DB_PASSWORD:
                secret: db-conn
                key: password                                     # 1) If the env name is different from secret key, secret key has to be set.
              endpoint:
                secret: db-conn                                   # 2) If the env name is the same as the secret key, secret key can be omitted.
              username:
                secret: db-conn
              # environments refer to oss-conn secret
              BUCKET_NAME:
                secret: oss-conn
                key: Bucket

    - name: sample-db
      type: alibaba-rds
      properties:
        name: sample-db
        engine: mysql
        engineVersion: "8.0"
        instanceClass: rds.mysql.c1.large
        username: oamtest
        secretName: db-conn

    - name: sample-oss
      type: alibaba-oss
      properties:
        name: velaweb
        secretName: oss-conn

Apply it and verify the application.

$ kubectl port-forward deployment/express-server 80:80
Forwarding from 127.0.0.1:80 -> 80
Forwarding from [::1]:80 -> 80
Handling connection for 80
Handling connection for 80

Provision and consume cloud resource in different applications

In this section, cloud resource will be provisioned in one application and consumed in another application.

Provision Cloud Resource

Instantiate RDS component with alibaba-rds workload type in an Application to provide cloud resources.

As we have claimed an RDS instance with ComponentDefinition name alibaba-rds. The component in the application should refer to this type.

apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: baas-rds
spec:
  components:
    - name: sample-db
      type: alibaba-rds
      properties:
        name: sample-db
        engine: mysql
        engineVersion: "8.0"
        instanceClass: rds.mysql.c1.large
        username: oamtest
        secretName: db-conn

Apply the application to Kubernetes and a RDS instance will be automatically provisioned (may take some time, ~2 mins).

A secret db-conn will also be created in the same namespace as that of the application.

$ kubectl get application
NAME       AGE
baas-rds   9h

$ kubectl get rdsinstance
NAME           READY   SYNCED   STATE     ENGINE   VERSION   AGE
sample-db-v1   True    True     Running   mysql    8.0       9h

$ kubectl get secret
NAME                                              TYPE                                  DATA   AGE
db-conn                                           connection.crossplane.io/v1alpha1     4      9h

$ ✗ kubectl get secret db-conn -o yaml
apiVersion: v1
data:
  endpoint: xxx==
  password: yyy
  port: MzMwNg==
  username: b2FtdGVzdA==
kind: Secret

Consume the Cloud Resource

In this section, we will show how another component consumes the RDS instance.

Note: we recommend defining the cloud resource claiming to an independent application if that cloud resource has standalone lifecycle.

Now create the Application to consume the data.

apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: webapp
spec:
  components:
    - name: express-server
      type: webconsumer
      properties:
        image: zzxwill/flask-web-application:v0.3.1-crossplane
        ports: 80
        dbSecret: db-conn

$ kubectl get application
NAME       AGE
baas-rds   10h
webapp     14h

$ kubectl get deployment
NAME                READY   UP-TO-DATE   AVAILABLE   AGE
express-server-v1   1/1     1            1           9h

$ kubectl port-forward deployment/express-server 80:80

We can see the cloud resource is successfully consumed by the application.