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Version: v1.0

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.

Last updated on by Jianbo Sun