Currently the document Change the Size of the Oplog doesn't mention the roles/privileges required to resize the oplog.

Before MongoDB 3.2.12, the admin user with readWriteAnyDatabase or dbAdminAnyDatabase roles have the privileges on the local database. So the admin user should not have any issue to execute the commands outlined in the document to resize the oplog.

However, since 3.2.12, `*AnyDatabase` roles no longer provide access rights to the `config` or `local` databases (SERVER-26839). So if we don't grant the role/privilege on the `local` database explicitly to the admin user, the user may not be able to execute these commands.