SymptomsWhen I log in to Parallels Plesk Panel installed inside a Virtuozzo container, I get the Plesk diagnostics page.
CauseThe issue is caused by the fact that the fully qualified domain name (FQDN) of the container cannot be resolved to the IP address by the service container.
To verify this, run this command on the node:
vzctl exec 1 nslookup server.domain.tld
(replacing server.domain.tld with the FQDN of the container).
ResolutionTo fix the issue, make sure that the service container has DNS servers configured in the IP configuration of its network adapter and is able to reach the DNS servers. The most common misconfiguration is that the service container has an automatically assigned IP address which is not routed to the subnet where DNS servers reside.
To fix the issue, it is necessary to enable NAT on the service container by using this command:
vzctl set 1 --nat on --save