Installation steps required to setup pure memory Alpine in LXD container

I've taken on several new clients recently with WordPress sites designed by clueless developers.

For example, one site requires nearly 1000 SQL SELECTs + 100s of UPDATEs to render one page.

Trying to... replumb all this SQL + keep the site running looks to be very complex + time consuming.

As an interim step, seems like running a version of Alpine which boots to memory + runs completely out of memory is the only hope for this type of site.

I can manage MariaDB/MySQL replication, so data volatility isn't an issue.

I'd like to setup LXD containers running Alpine, so when containers start all system files are memory based (so no disk i/o at all).

Someone point me to some URL which gives clues about how to do this.

Thanks.