• A clear description of the issue

When a client connects to ProxySQL , this only returns to the client its own certificate.
If ProxySQL server's certificate is not signed by a trusted Certificate Authority (CA) , the client is not able to verify it.
ProxySQL should send the full certificate chain

• ProxySQL version

All to current version (2.7.3 and 3.0)

• OS version

Any

• The steps to reproduce the issue

Will add this later, for now this a place holder

• The full ProxySQL error log (default location: /var/lib/proxysql/proxysql.log)

Nothing relevant

• Possible solution

On ProxySQL's side, the server certificate and the intermediate certificate must be bundled.
Nonetheless, it seems that ProxySQL only load the first certificate from the bundle.
So when we load the certificate we should loop until there are no more certificates.