We need to implement a proxy only by using iptables in a container and all traffic from other containers use this container to reach internet. Additionally in this proxy, drop trafffic to yahoo.com domain and allow the rest.
I've a Oracle VM Box in windows that hosts a Ubuntu VM. In this VM, I've installed docker with 4 containers having Ubuntu image as shown here:
Requirement is any traffic from avant3, avant4 or avant2 should use avant1 as proxy to reach internet. avant1 should only implement iptables rules to become a tcp proxy.
In avant1 container in interactive mode, did the following as per this link:
iptables --table nat --append POSTROUTING --out-interface eth0 -j MASQUERADE
iptables --append FORWARD --in-interface eth1 -j ACCEPT
Going into avant3 and executing curl and specifying avant1 as proxy, getting this response:
root@340787f0b409:/# curl -x 172.19.0.3 "www.google.com" -I
curl: (7) Failed to connect to 172.19.0.3 port 1080 after 0 ms: Connection refused
root@340787f0b409:/# curl -x 172.19.0.3:80 "www.google.com" -I
curl: (7) Failed to connect to 172.19.0.3 port 80 after 0 ms: Connection refused
root@340787f0b409:/# 18.0
Can anybody guide me on the mistake I'm doing to achieve my requirement?
