In Function Compute, you can use a function to call database APIs to insert or query data. In most cases, instance status is not shared among different execution environments in Function Compute. You can persist structured data in a database to share instance status. This topic uses Python 3 as an example to describe how to use Serverless Devs to deploy a function to access an ApsaraDB for Lindorm database.

Prerequisites

  • Create a Lindorm instance.
    Notice
    • Make sure that the database instance you created is in the same region as the function that needs to access the database instance.

    • We recommend that you create the database instance in a zone that supports Function Compute.

      If your resources are not deployed in the zones shown in the following list, create a vSwitch in your virtual private cloud (VPC). The vSwitch must be in the same zone as Function Compute. Also, you must specify the vSwitch ID when you configure the VPC for Function Compute. vSwitches in the same VPC can communicate with each other over the private network. Therefore, Function Compute can use the vSwitch to access resources in the VPC that reside in other zones. For more information, see How can I resolve the "vSwitch is in unsupported zone" error?.

      Region Region ID Zones supported by Function Compute
      China (Hangzhou) cn-hangzhou cn-hangzhou-f, cn-hangzhou-g, cn-hangzhou-h
      China (Shanghai) cn-shanghai cn-shanghai-b, cn-shanghai-e, cn-shanghai-g, cn-shanghai-f
      China (Qingdao) cn-qingdao cn-qingdao-c
      China (Beijing) cn-beijing cn-beijing-h, cn-beijing-c, cn-beijing-e, cn-beijing-f
      China (Zhangjiakou) cn-zhangjiakou cn-zhangjiakou-b, cn-zhangjiakou-a
      China (Hohhot) cn-huhehaote cn-huhehaote-a, cn-huhehaote-b
      China (Shenzhen) cn-shenzhen cn-shenzhen-e, cn-shenzhen-d
      China (Chengdu) cn-chengdu cn-chengdu-a, cn-chengdu-b
      China (Hong Kong) cn-hongkong cn-hongkong-c
      Singapore (Singapore) ap-southeast-1 ap-southeast-1a, ap-southeast-1b
      Australia (Sydney) ap-southeast-2 ap-southeast-2a, ap-southeast-2b
      Malaysia (Kuala Lumpur) ap-southeast-3 ap-southeast-3a
      Indonesia (Jakarta) ap-southeast-5 ap-southeast-5a, ap-southeast-5b
      Japan (Tokyo) ap-northeast-1 ap-northeast-1b, ap-northeast-1a
      UK (London) eu-west-1 eu-west-1a
      Germany (Frankfurt) eu-central-1 u-central-a, eu-central-1a, eu-central-1b
      US (Silicon Valley) us-west-1 us-west-1a, us-west-1b
      US (Virginia) us-east-1 us-east-1b, us-east-1a
      India (Mumbai) ap-south-1 ap-south-1a, ap-south-1b
  • Install Serverless Devs and Docker.
  • Configure Serverless Devs
  • Create a security group

    Create a default security group in the VPC where the database instance is deployed. If you want to use an existing security group, make sure that the security group allows outbound traffic to the ports and private CIDR blocks of the database instance. By default, the security group allows all outbound traffic.

Configure the whitelist for the database

In ApsaraDB for Lindorm, you can add IP addresses to the whitelist or specify security groups to access the database. We recommend that you add IP addresses to the whitelist to access the database.

  1. Log on to the Lindorm console.
  2. On the Instance list page, find the Lindorm instance to be accessed and click the instance ID. You are redirected to the Instance Details page.
  3. In the left-side navigation pane, click Access Control.
  4. On the Whitelists page, click Modify Whitelist.
  5. In the Modify Whitelist dialog box, enter the CIDR block that is allowed to access the database and click OK.
    Notice The IP address that you want to specify must be the CIDR block of the vSwitch that you added in the network configuration of Function Compute.

Deploy and invoke functions

  1. Initialize a project.
    s init start-fc-lindorm-python -d start-fc-lindorm-python
  2. Access the project.
    cd start-fc-lindorm-python
  3. Edit the s.yaml file.

    Example:

    edition: 1.0.0          
    name: fcDeployApp       
    access: "default"  
    
    services:
      fc-db-lindorm-python: 
        component: devsapp/fc  
        props:
          region: cn-hangzhou
          service:
            name: fc-db-demo
            description: 'demo for fc visit db'
            internetAccess: true
            vpcConfig:
              vpcId: vpc-bp1hcg467ekqsv0zr**** # The ID of the VPC where the database instance resides. 
              securityGroupId: sg-bp1gg2tyyzuvz8x0**** # The ID of the security group. 
              vswitchIds:
                - vsw-bp1sciqyju9qxocys**** # Make sure that the CIDR block of the vSwitch is added to the whitelist of the database instance. 
          function:
            name: lindorm
            description: visit lindorm
            runtime: python3
            codeUri: ./code
            handler: index.handler
            memorySize: 256
            timeout: 30
            environmentVariables:
              DATABASE_ADDR: ld-bp13c5s05n1mu****-proxy-lindorm.lindorm.rds.aliyuncs.com:30** # The endpoint of the database. 
              USER: r*** # The name of the database user. 
              PASSWORD: r*** # The password of the database user. 
  4. Run the following command to build the project.
    s build --use-docker
  5. Run the following command to deploy the project.
    s deploy -y
  6. Run the following command to invoke a function.
    s invoke -e "{}"

    The expected command output is as follows:

    [2021-09-22T22:54:19.851] [INFO ] [S-CLI] - Start ...
    ========= FC invoke Logs begin =========
    FC Invoke Start RequestId: a41a7647-cf8b-466d-a63f-59635043453e
    2021-09-22T14:54:20.289Z a41a7647-cf8b-466d-a63f-59635043453e [INFO] start to test Lindorm 
    2021-09-22T14:54:20.291Z a41a7647-cf8b-466d-a63f-59635043453e [WARNING] Cluster.__init__ called with contact_points specified, but no load_balancing_policy. In the next major version, this will raise an error; please specify a load-balancing policy. (contact_points = ['ld-bp13c5s05n1mu****-proxy-lindorm.lindorm.rds.aliyuncs.com'], lbp = None)
    2021-09-22T14:54:20.301Z a41a7647-cf8b-466d-a63f-59635043453e [WARNING] Downgrading core protocol version from 66 to 65 for 192.168.**.**:90**. To avoid this, it is best practice to explicitly set Cluster(protocol_version) to the version supported by your cluster. http://datastax.github.io/python-driver/api/cassandra/cluster.html#cassandra.cluster.Cluster.protocol_version
    2021-09-22T14:54:20.309Z a41a7647-cf8b-466d-a63f-59635043453e [WARNING] Downgrading core protocol version from 65 to 5 for 192.168.**.**:90**. To avoid this, it is best practice to explicitly set Cluster(protocol_version) to the version supported by your cluster. http://datastax.github.io/python-driver/api/cassandra/cluster.html#cassandra.cluster.Cluster.protocol_version
    2021-09-22T14:54:20.317Z a41a7647-cf8b-466d-a63f-59635043453e [ERROR] Closing connection <LibevConnection(13962401490****) 192.168.**.**:90**> due to protocol error: Error from server: code=000a [Protocol error] message="Beta version of the protocol used (5/v5-beta), but USE_BETA flag is unset"
    2021-09-22T14:54:20.318Z a41a7647-cf8b-466d-a63f-59635043453e [WARNING] Downgrading core protocol version from 5 to 4 for 192.168.**.**:90**. To avoid this, it is best practice to explicitly set Cluster(protocol_version) to the version supported by your cluster. http://datastax.github.io/python-driver/api/cassandra/cluster.html#cassandra.cluster.Cluster.protocol_version
    2021-09-22T14:54:20.364Z a41a7647-cf8b-466d-a63f-59635043453e [INFO] Using datacenter 'datacenter1' for DCAwareRoundRobinPolicy (via host '192.168.**.**:90**'); if incorrect, please specify a local_dc to the constructor, or limit contact points to local cluster nodes
    2021-09-22T14:54:20.550Z a41a7647-cf8b-466d-a63f-59635043453e [INFO] # row: Row(id=1, address='hangzhou', age=11, name='testname')
    FC Invoke End RequestId: a41a7647-cf8b-466d-a63f-59635043453e
    
    Duration: 267.05 ms, Billed Duration: 268 ms, Memory Size: 256 MB, Max Memory Used: 87.87 MB
    ========= FC invoke Logs end =========
    
    FC Invoke Result:
    null
    
    
    End of method: invoke

What to do next

Collection of cases to access the database instance by using Function Compute