Override the default DNS server list for vRouter

Override the default DNS server list for vRouter

Warning

This feature is available starting from the MCP 2019.2.3 maintenance update. Before enabling the feature, follow the steps described in Apply maintenance updates.

When a network uses the default DNS mode, the DNS requests to a VM are forwarded to the namespaces defined in /etc/resolv.conf on a dedicated OpenStack compute node.

Using the resolv_conf_file option, you can specify a file that contains a list of DNS nameserver that contrail-vrouter-agent will use as a non-default source of custom nameservers. This option must contain an absolute path to a custom nameserver file. This file must have the same structure as /etc/resolv.conf with appropriate permissions.

To override the default DNS server list for vRouter:

  1. Log in to any OpenStack compute node.

  2. In /etc/contrail/contrail-vrouter-agent.conf, uncomment resolv_conf_file = and add an absolute path to your custom nameserver file:

    [DNS]
    resolv_conf_file=<absolute_path_to_custom_nameserver_file>
    
  3. Restart contrail-vrouter-agent:

    service contrail-vrouter-agent restart
    
  4. Wait until contrail-vrouter-agent is up and running. To verify the service status, refer to Verify the OpenContrail status.

  5. Repeat the steps 2-4 on the remaining cmp nodes.