Migrating to a Scalable Wordpress Solution

TLDR; I want to manage and configure multiple LEMP stacks with Terraform and Chef/Ansible to host WordPress sites without losing the data when a droplet is destroyed.

Here are the questions that I am looking to have answered:

• Is Terraform and Chef/Ansible the right direction to move in to help me manage multiple WordPress sites?
• Is it better to update NGINX configuration by destroying and rebuilding a droplet with Terraform, or is it better to change the file across all servers with Chef/Ansible
• If I use Terraform to configure NGINX, PHP, WordPress Config Files, etc… How do I secure the WordPress database and Uploads data so that when a Droplet is destroyed by Terraform, the site remains live without interruption
• Is Block Storage or GlusterFS a better solution for managing the Data of 100’s of different WordPress sites
• Is Chef or Ansible better for this purpose

Here is the context for those questions: I design and host WordPress websites in my area. For a lack of a deeper understanding of automation, I have been manually deploying the sites on DigitalOcean droplets and configuring them each independently. The only difference between the servers is the WordPress database and Uploads data, which I feel justifies the move to automate deployment through Terraform. I guess what I am looking for is a critical ear to interpret my plan and guide me in the right direction.

The plan is to set up a centralized management server which will host Terraform for infrastructure and docker automation, Chef (or Ansible) for configuration management, and an OpenVPN server for channeling secure access to WordPress servers. All servers are built on a LEMP stack and have carefully secured and optimized NGINX configurations.

The goal is to set it up so that when a client request a website designed for them I can easily spin up a new droplet through Terraform which containerizes the LEMP stack and configures everything (like NGINX files) with Chef or Ansible. I would also like to be able to update server files in one place and have it update across all servers. This is where I could really use some guidance.

Does it make sense to update configuration files (like NGINX or PHP) with Chef/Ansible or does it make sense to rebuild the droplets with Terraform so there is no configuration drift. If I do it with Terraform then the next problem that presents itself is figuring out a way to keep WordPress sites and data live when Terraform destroys a droplet. There are some pretty good tutorials on here about setting up GlusterFS or block storage, so I could potentially host all of the WordPress data on separate servers and use Terraform to manage the processing servers.

I appreciate the community taking the time to read this and any feedback or guidance would be greatly appreciated.