You need mongodb if you plan to use auth, accessLogs or errorLogs directives, otherwise you don’t need. If you just want to have access to 10 separate Strapi apps through a single app you just need to add 10 configs in config/servers like this:
file: config/servers/available/my-strapi-app-X.json
{
"serverName": ["my-tenant-1.com"],
"server": {
"proxyPass": "localhost:1337",
"...": "..."
}
}
Replace the serverName and port for every tenent.
Of course, you need to proxyPass those clients in nginx too to the proxy app you are creating using express-access-proxy, and you should read the docs about how to enable the added configs and about all the things you can do using that app. If you know some nginx it shouldn’t be hard since it follows the same principles.