Function Compute:Configure an OSS bucket

Step 1: Configure an OSS mount target

1. Log on to the Function Compute console. In the navigation pane on the left, choose Functions > Functions.

2. In the top navigation bar, select a region. On the Functions page, click the target function.

3. On the function details page, click the Configuration tab. Click Edit next to Advanced Configuration. In the Advanced Configuration panel, find the Storage section and enable Mount OSS Bucket. Configure the following parameters as needed, and then click Deploy.

   Parameter	Description	Example
   OSS Mount Target: Enter the information for the OSS mount target.
   Bucket	Select an existing bucket. To create a new OSS bucket, click Create New OSS Bucket below to go to the OSS console and create one. For information about the costs of using OSS, see Billing overview for OSS.	example-bucket
   Bucket Subdirectory	Specify a subdirectory in the bucket. This must be an absolute path. If you leave this empty or set it to /, the root directory of the bucket is mounted.	/files
   OSS Endpoint	After you select a bucket, its corresponding endpoint is selected by default. You can select Custom Endpoint and change the endpoint value as needed. For information about the endpoints for OSS in different regions, see Regions and endpoints. Note If you select a bucket in the same region as your Function Compute function, use the internal OSS endpoint. If you select a bucket in a different region, you must use the public OSS endpoint. This incurs charges for outbound traffic over the Internet.	Default address
   Local Directory	Specify a local directory in the function's runtime environment. The directory must be a subdirectory of /home, /mnt, or /data.	/mnt/oss
   Local Directory Permissions	Select the access permissions for the local directory after the bucket is mounted. You can set the permissions to Read-only or Read/Write.	Read/Write

   Note

   The OSS mount feature is dependent on the function's network configuration. If a function is configured to access only a VPC and Allow Function To Access Internet On Default NIC is set to No, the function must be able to access the Internet through that VPC to use a public OSS endpoint. For more information, see Configure a static public IP address.

Step 2: Access files in the mounted OSS directory

After you configure the OSS mount target, you can access files in the mounted OSS directory in the same way that you access local files.

1. On the function details page, click the Code tab. Write your code in the editor, and then click Deploy Code.

   This topic uses a Python function as an example. The sample code is as follows.

   import os
   
   
   def handler(event, context):
       # Mount directory
       mount_path = '/mnt/oss'
       
       # List files in the mount directory
       files = os.listdir(mount_path)
       print("Files in OSS mount:", files)  
       # Read a file from the mount directory
       file_path = os.path.join(mount_path, 'example.txt')
       if os.path.exists(file_path):
           with open(file_path, 'r') as file:
               content = file.read()
               print("Content of example.txt:", content)
       else:
           print("example.txt does not exist.")
       # Write a file to the mount directory
       write_path = os.path.join(mount_path, 'output.txt')
       with open(write_path, 'w') as file:
           file.write("Hello, OSS mount!")
           print("Wrote to output.txt in OSS mount.")
       
       return "Function execution completed."
     

   Note

   In the code, replace example.txt with the name of an actual file in your mounted OSS directory.

2. After the code is deployed, on the Code tab, click Test Function.

   After the execution is complete, you can view the results below the Code tab. The Log Output tab shows the content of the example.txt file read from the OSS directory. In the OSS console, you can see that the output.txt file has been written to the corresponding mounted directory.

Check the storage class of your OSS bucket. If the storage class is Archive Storage or Cold Archive, files in the bucket are in a frozen state. These files must be restored before they can be accessed. Set the storage class of your OSS bucket to Standard.