Help Center/ Cloud Application Engine/ User Guide/ Component Configurations/ Configuring RDS
Updated on 2024-07-01 GMT+08:00
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Configuring RDS

To store application data permanently, you need to use Relational Database Service (RDS). Based on the cloud computing platform, CAE provides RDS for MySQL which is reliable, scalable, easy to manage, and ready for use. RDS for MySQL enables you to easily set and scale relational databases on the cloud. Using the RDS service, you can perform nearly all necessary tasks without programming. This service simplifies operation procedures and reduces routine O&M workloads, so that you can focus on application and service development.

You can bind a cloud database in component configuration. Then, you can read environment variables to obtain MySQL information during application running to access MySQL.

The cloud database to be bound must be in the same VPC as the environment.

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.

Parent topic: Component Configurations