Set reverse proxy websockets in Apache 2.4 using socket.io 1.0. Needs mod_rewrite module, this version uses SSL. As seen here https://serverfault.com/questions/616370/configuring-apache-2-4-mod-proxy-wstunnel-for-socket-io-1-0

socket.io-1-0-apache-2.4-ssl.conf

<VirtualHost *:80>

	ServerName forum.example.com
	Redirect permanent / https://forum.example.com

</VirtualHost>

<VirtualHost *:443>

	ServerName forum.example.com

	SSLEngine on                                                                
	SSLProtocol all -SSLv2                                                      
	SSLCipherSuite ALL:!ADH:!EXPORT:!SSLv2:RC4+RSA:+HIGH:+MEDIUM                

	SSLCertificateFile /etc/apache2/ssl/example-com/forum.ssl.crt                           
	SSLCertificateKeyFile /etc/apache2/ssl/example-com/private.key                        
	SSLCertificateChainFile /etc/apache2/ssl/example-com/sub.class1.server.ca.pem 

#	ServerAdmin webmaster@localhost

	<Proxy *>
		Require all granted
	</Proxy>

	ProxyRequests off
	ProxyVia on

	RewriteEngine On
	RewriteCond %{REQUEST_URI}  ^/socket.io            [NC]
	RewriteCond %{QUERY_STRING} transport=websocket    [NC]
	RewriteRule /(.*)           ws://localhost:4567/$1 [P,L]

	ProxyPass        /socket.io http://localhost:4567/socket.io
	ProxyPassReverse /socket.io http://localhost:4567/socket.io

	<Location />
		ProxyPass http://127.0.0.1:4567/
		ProxyPassReverse http://127.0.0.1:4567/
	</Location>

	ErrorLog /home/username/logs/apache/forum-error.log
	CustomLog /home/username/logs/apache/forum-access.log combined

</VirtualHost>