Function Compute:Configure custom DNS

Limits

The custom DNS feature supports only the built-in runtimes of Function Compute and custom runtimes.

Before you start

Create a function

Configure DNS settings

1. Log on to the Function Compute console. In the left-side navigation pane, click Functions.

2. In the top navigation bar, select a region. On the Functions page, click the function that you want to manage.

3. On the function details page, click the Configurations tab.

4. In the left-side navigation pane, click the DNS tab. On the DNS tab, click Modify. In the DNS panel, configure the following parameters as prompted and click OK.

   Parameter	Description	Example
   Name Servers	The IP address of the DNS server. You can specify one or more IP addresses.	223.5.5.5 223.6.6.6
   Search Domain	The search domain of the DNS server. You can specify one or more search domains. If the DNS server cannot resolve a domain name, search domains are appended to the domain name, and then the DNS server resolves the domain name again.	example.com
   DNS Options	The configuration items in the resolv.conf file. Each item corresponds to a key-value pair in the key:value format, in which the key is required.	attempts:1

5. Verify whether the custom DNS settings that you configured take effect.

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

   2. Write code in the code editor, click Deploy, and then click Test Function.

      Sample code (Python 3):

      # -*- coding: utf-8 -*-
      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 section, view the corresponding content generated by resolv.conf. In the Log Output section, view the IP address of the returned domain name.