c-ares DNS resolver (proto)¶

This extension has the qualified name envoy.network.dns_resolver.cares

Note

This extension is intended to be robust against both untrusted downstream and upstream traffic.

Tip

This extension extends and can be used with the following extension category:

This extension must be configured with one of the following type URLs:

extensions.network.dns_resolver.cares.v3.CaresDnsResolverConfig¶

Configuration for c-ares DNS resolver.

{
  "resolvers": [],
  "use_resolvers_as_fallback": ...,
  "filter_unroutable_families": ...,
  "dns_resolver_options": {...}
}

resolvers: (repeated config.core.v3.Address, REQUIRED) A list of dns resolver addresses. use_resolvers_as_fallback below dictates if the DNS client should override system defaults or only use the provided resolvers if the system defaults are not available, i.e., as a fallback.

use_resolvers_as_fallback: (bool) If true use the resolvers listed in the resolvers field only if c-ares is unable to obtain a nameserver from the system (e.g., /etc/resolv.conf). Otherwise, the resolvers listed in the resolvers list will override the default system resolvers. Defaults to false.

filter_unroutable_families: (bool) The resolver will query available network interfaces and determine if there are no available interfaces for a given IP family. It will then filter these addresses from the results it presents. e.g., if there are no available IPv4 network interfaces, the resolver will not provide IPv4 addresses.

dns_resolver_options: (config.core.v3.DnsResolverOptions) Configuration of DNS resolver option flags which control the behavior of the DNS resolver.