How to set up subdirectory Multisite in WordPress on Azure App Service

Once these steps were followed we were able to create subdirectory sites but users were stuck in a redirect loop when attempting to access the dashboard for subdirectory network sites.  Since the new WordPress Azure app uses nginx we needed to make the following updates:

1.  Create a nginx.conf file based on the file found at /etc/nginx/conf.d/default.conf and place it in /home/site/wwwroot

2.  Add the lines necessary for multisite directly below 'index index.php;' on line 14.  We used an FTP client for this.

if (!-e $request_filename) {
  rewrite /wp-admin$ $scheme://$host$request_uri/ permanent;
  rewrite ^(/[^/]+)?(/wp-.*) $2 last;
  rewrite ^(/[^/]+)?(/.*\.php) $2 last;
}

3. Update /dev/startup.sh to contain:

cp /home/site/wwwroot/nginx.conf /etc/nginx/conf.d/default.conf
/usr/sbin/nginx -s reload

4. Stop and start the app to load the new configuration (or run the commands from 3 in the SSH terminal)

We referenced this document for the multisite configurations: Nginx – Advanced Administration Handbook | Developer.WordPress.org  and this document for how to update the app's nginx configuration: wordpress-linux-appservice/WordPress/configuring_nginx_for_wordpress.md at main · Azure/wordpress-linux-appservice · GitHub