Apache: Invalid command ProxyRequests when setting up jenkins

I setup a new Vhost for jenkins:

<VirtualHost *:80>
    ServerAdmin webmaster@localhost
    ServerName ci.company.com
    ServerAlias ci
    ProxyRequests Off
    <Proxy *>
        Order deny,allow
        Allow from all
    </Proxy>
    ProxyPreserveHost on
    ProxyPass / http://localhost:8080/
</VirtualHost>

...which uses proxy and when i restart apache I get error like this:

Invalid command 'ProxyRequests', perhaps misspelled or defined by a module not included in the server configuration

Solution 1:

You should enable proxy. Run a command:

 sudo a2enmod proxy
 sudo /etc/init.d/apache2 restart

Solution 2:

proxy module must be disable. Enable it using below command

a2enmod proxy

If you don't have access to root, you can use

sudo a2enmod proxy

After that restart apache server using

service apache2 reload

Solution 3:

 sudo a2enmod proxy
 sudo a2enmod proxy_http
 systemctl restart apache2

If you don't enable proxy_http you get this error in the apache error log file for the site:

AH01144: No protocol handler was valid for the URL / (scheme 'http'). If you are using a DSO version of mod_proxy, make sure the proxy submodules are included in the configuration using LoadModule.