Function Compute:Configure custom DNS

Limitations

The Custom DNS feature does not support Custom Image.

Prerequisites

You have created a function, excluding GPU-accelerated functions.

Configure DNS

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

2. In the top navigation bar, select a Region. On the Function page, click the target function.

3. On the function details page, click the Configuration tab. To the right of Advanced Settings, click Modify. In the Advanced Settings panel, find the DNS section, configure the following parameters, and click Deploy.

   Parameter	Description	Example
   Name Servers	Specifies the IP addresses of the DNS servers. You can add multiple addresses.	223.5.5.5 223.6.6.6
   Search Domain	A DNS search domain. You can add multiple search domains. If a domain name fails to resolve, the system appends a search domain and retries the query.	example.com
   DNS Options	Each configuration item in the resolv.conf file is a key-value pair in the key:value format, where the key is required.	attempts:1

4. Verify that the Custom DNS settings are effective.

   1. On the function details page, click the Code tab.

   2. In the code editor, write your code, click Deploy, and then click Test Function.

      Sample code (Python 3):

      import logging
      import subprocess
      
      def handler(event, context):
        logger = logging.getLogger()
        f = open('/etc/resolv.conf')
        logger.info("".join(f.readlines()))
        f.close()
        output = subprocess.check_output(["ping", "-c", "1", "www.aliyun.com"])
        return output

   3. On the Code tab, view the execution result: in the Response area, view the content generated for resolv.conf, and in the Log Output area, view the IP address of the returned domain name.