Configuring RDS

Prerequisites

You have created an RDS MySQL DB instance. For details, see Buy a DB Instance.

Procedure

1. Log in to CAE.
2. Choose Component Configurations.
3. Select the target component from the drop-down list in the upper part of the page.
   Figure 1 Selecting a component
   

4. Click Configure in the Relational Database Service (RDS) module.
5. You need to set RDS environment variables in your code when configuring an RDS instance for the first time. Available variables:

   Variable	Description
   RDS_ADDRESS	Private IP address of the RDS database instance
   RDS_DB_NAME	Database name
   RDS_USER_NAME	Database username
   RDS_PASSWORD	Database password
   RDS_PORT	Database port

   After the configurations take effect, user code can obtain RDS database parameters through environment variables and use these parameters to connect to the databases for adding, deleting, modifying, and querying data.

   For example, use GORM to connect to postgreg:

   func initDB() (*gorm.DB, error) {
   // Obtain parameters from environment variables.
   dbAddress := os.Getenv("RDS_ADDRESS")
   dbName := os.Getenv("RDS_DB_NAME")
   dbUserName := os.Getenv("RDS_USER_NAME")
   dbPassword := os.Getenv("RDS_PASSWORD")
   dbPort := os.Getenv("RDS_PORT")
   
   // Use the obtained parameters to build DSN.
   dbDSN := fmt.Sprintf("host=%s port=%s user=%s dbname=%s sslmode=disable password=%s",dbAddress, 5432, dbUserName, dbName, dbPassword)
   
   // Connect to a database.
   instance, err := gorm.Open("postgres", dbDSN)
   if err != nil {
   log.Println("connect db failed : " + err.Error())
   return nil, err   
   }
   
   return instance, nil
   }

6. In the right pane, select an RDS instance.

   If the existing RDS instances do not meet service requirements:

   1. Click Go to RDS Console to create an RDS instance.

   2. Click Next to configure and buy the instance.

7. Set the parameters by referring to Table 1.

   Table 1 Configuring RDS

   Parameter	Description
   RDS Instance	You can select an RDS database instance in the same VPC as CAE.
   Database	Select the target database.
   Database Username	Select a user under the database.
   Database Password	Enter a database password. The password is mandatory.
   Confirm Password	Enter the password again.
   Database Port	Enter a database port.

8. Click Save.
9. Make the configurations take effect.
   • If the component has been deployed, click Activate Settings in the upper part of the page. In the dialog box displayed on the right, confirm the configurations and click OK for the configurations to take effect.
   • If the component has not been deployed, click Set and Deploy Component in the upper part of the page. In the dialog box displayed on the right, click OK. After the deployment is complete, the configurations take effect.