Feature Description

Some environments have trouble using Site Kit due to rare complications with default IP resolution. Allowing this to use a specific version can help in some situations.

For more information, see the related functionality in cURL https://daniel.haxx.se/blog/2020/04/20/curl-ootw-ipv4/

Also https://docs.guzzlephp.org/en/6.5/request-options.html#force-ip-resolve

Do not alter or remove anything below. The following sections will be managed by moderators only.

Acceptance criteria

• A new googlesitekit_force_ip_resolve filter should be implemented
  • Default null
  • The only values allowed/recognized from it other than the default should be the strings v4 and v6
• The filter should control the IP resolution of requests made by the Google_Site_Kit_Client

Implementation Brief

• Finish and merge Update HTTP client config in factory to allow for controlling IP resolution  #7867

Test Coverage

• Update coverage in Client_FactoryTest

QA Brief

• No QA is needed here. Changes in hte http config are tested using phpunit tests.

Changelog entry

• Allow the IP version to be specified for server-side requests.