ApsaraDB RDS:Use ApsaraDB RDS with OSS to store data in various structures

Sample code

The sample code is written by using Python 3.6.

For more information about how to install OSS SDK for Python, see Installation.

1. Configure environment variables.

   Linux or macOS

   export OSS_ACCESS_KEY_ID=STS.xxxxxx
   export OSS_ACCESS_KEY_SECRET=xxxxxx
   export OSS_SESSION_TOKEN=xxxxxx

   Windows

   set OSS_ACCESS_KEY_ID=STS.xxxxxx
   set OSS_ACCESS_KEY_SECRET=xxxxxx
   set OSS_SESSION_TOKEN=xxxxxx

   Note

   Temporary access credentials are obtained from Security Token Service (STS) and valid for one hour. We recommend that you use Resource Access Management (RAM) roles to automatically rotate the credentials.

2. Initialize the oss2.Bucket class.

   #!/usr/bin/env python
   import oss2
   from oss2.credentials import EnvironmentVariableCredentialsProvider
   
   # Use V4 signatures and credentials obtained from environment variables.
   auth = oss2.ProviderAuthV4(EnvironmentVariableCredentialsProvider())
   
   # Enter the endpoint. The HTTPS protocol must be included.
   endpoint = 'https://oss-cn-hangzhou.aliyuncs.com'  # In this example, the endpoint of the China (Hangzhou) region is used.
   
   # Specify a region and create a bucket.
   bucket = oss2.Bucket(
       auth,
       endpoint,
       'examplebucket',
       region='cn-hangzhou' # The region corresponding to the endpoint.
   )

3. Upload an object.

   # Specify the full path of the object and the full path of the local file. The full path of the object cannot contain the bucket name. 
   # By default, if you do not specify the full path of a local file, the local file is uploaded from the path of the project to which the sample program belongs. 
   # Upload the info_old.txt object.
   res1 = bucket.put_object_from_file("info_key.txt", "info_old.txt")
   print("res1-{0}".format(res1.status))
       
   # Upload the picture_old.png object.
   res2 = bucket.put_object_from_file("picture_key.png", "picture_old.png")
   print("res2-{0}".format(res2.status))

4. Retrieve the object.

   # Specify the full path of the object. The full path cannot contain the bucket name, such as info_key.txt. 
   # Download the object and save it as a file in the specified path, such as D:\\info_new.txt. If a file that has the same name already exists, the downloaded object overwrites the file. If no file that has the same name exists, a file is created. 
   res3 = bucket.get_object_to_file("info_key.txt", "D:\\info_new.txt")
   print("res2-{0}".format(res3.status))
   
   res4 = bucket.get_object_to_file("picture_key.png", "D:\\picture_new.png")
   print("res4-{0}".format(res4.status))

The Elastic Compute Service (ECS) application code specifies that user IDs are stored in your RDS instance and that user profile pictures are stored in your OSS bucket. The following example shows a Python code snippet:

#!/usr/bin/env python
import oss2
from oss2.credentials import EnvironmentVariableCredentialsProvider
import mysql_client

def conn_client():
    sql = "SELECT id FROM users LIMIT 1" # Assume that the user ID is obtained from the users table.
    # Use V4 signatures and the standard credential provider.
    auth = oss2.ProviderAuthV4(EnvironmentVariableCredentialsProvider())
    endpoint = "https://oss-cn-hangzhou.aliyuncs.com" # Modify the protocol header.
    bucket = oss2.Bucket(auth, endpoint, 'oss-wwjtest', region='cn-hangzhou')

    # Run a database query.
    user_id = mysql_client.fetch_one(sql)  # Make sure that fetch_one returns a single value.
    object_path = f"{user_id}.png"  # You must specify a valid object name.
    local_path = f"your_path/{object_path}"  # You must use the actual path.

    # Download the object.
    bucket.get_object_to_file(object_path, local_path)
    # Upload the object.
    bucket.put_object_from_file(object_path, local_path)

if __name__ == '__main__':
    conn_client()