By default, Squid only allows connections from an authenticated user, or from an SSH session that originated from the same server.
The Squid configuration files are located in /opt/underpass/config/squid/
In the squid folder, edit the users file using your preferred text editor and use a passwd-generator to create your own user-password combination.
From the passwd-generator homepage, input your desired username and password. For the Mode, select Apache specific salted MD5. Finally, click on the Create .htpasswd file button.
In the users file, remove the entry for underpass and replace it with your newly generated username-password combination.
Any change to the squid configuration folder will require you to recreate the squid container. The SSH commands below will do just that:
cd /opt/underpass/
docker-compose up -d --force-recreate squid
You can change the port for Squid by changing the http_port number from /opt/underpass/config/squid/squid.conf
http_port 3128
Recreate the container afterwards:
cd /opt/underpass
docker-compose up -d --force-recreate squid
You will then have to open the new port from the Docker host. For instance, if you changed the Squid port from 3128 to 3888, you'll have to issue these commands from SSH as root:
firewall-cmd --remove-service=squid --permanent
firewall-cmd --zone=public --add-port=3888/tcp --permanent
firewall-cmd --reload