Apache http.conf with wildcard subdomains - regex

Question

I have a white-label web app that runs with subdomains to divide out the labels. Let's say cust1.app.com and cust2.app.com. I have SSL on my site, but I am having troubles making the site redirect from http to https. I want to do this all within http.conf, as opposed to .htaccess files. Here is my http.conf:
<VirtualHost *:443>
<Directory /var/www/html/>
Options -Indexes
Require all granted
AllowOverride All
</Directory>
ServerAlias *.app.com
DocumentRoot /var/www/app
SSLEngine on
SSLCertificateFile /var/www/certs/cert.pem
SSLCertificateKeyFile /var/www/certs/privkey.pem
SSLCertificateChainFile /var/www/certs/fullchain.pem
</VirtualHost>
<VirtualHost *:80>
ServerAlias *.app.com
RewriteEngine On
RewriteCond %{HTTPS} !=on
RewriteRule ^/?(.*) https://%{HTTP_HOST}/$1 [R,L]
</VirtualHost>
When visiting http://www.app.com or http://cust1.app.com, I get a simple ERR_CONNECTION_REFUSED, however when I manually put in the https, the site serves fine on all subdomains.
How do I redirect to https while honoring my wildcard subdomains?

Answer 1

Turns out I was missing the Listen directive for port 80, I must have deleted it from ports.conf or something at some point in the long and hair-pulling troubleshooting process. Here's my http.conf now:
Listen 80
Listen 443
<VirtualHost *:443>
<Directory /var/www/html/>
Options -Indexes
Require all granted
AllowOverride All
</Directory>
ServerAlias *.app.com
DocumentRoot /var/www/app
SSLEngine on
SSLCertificateFile /var/www/certs/cert.pem
SSLCertificateKeyFile /var/www/certs/privkey.pem
SSLCertificateChainFile /var/www/certs/fullchain.pem
</VirtualHost>
<VirtualHost *:80>
ServerAlias *.app.com
RewriteEngine On
RewriteCond %{HTTPS} !=on
RewriteRule ^/?(.*) https://%{HTTP_HOST}/$1 [R,L]
</VirtualHost>