Docker：如何从容器中访问服务器的公共IP？

Question

I'm running different apps as docker containers on a linux server. I'm able to access the docker containers just fine using SSL. The reverse proxy I'm using is traefik configured to proxy subdirectories instead of subdomains.

These are my containers:

Application A - accessible via https://abc.xyz/a

Application B - accessible via https://abc.xyz/b

Both applications are up and running and working correctly when accessing them from my browser.

Now I need to embed Application B in Application A . I know I could just use the container's internal IP (since they are on the same network), however, the embedded application must be accessible to Application A as well as to my local browser - so I need to use a publicly facing IP/URL.

The problem now is that I simply cannot access https://abc.xyz/b from Application A . All the below commands are executed inside the Application A docker container.

Ping is working:

$ ping abc.xyz
64 bytes from 150.150.150.150: seq=0 ttl=64 time=0.204 ms

So DNS is working.

However wget shows:

$ wget https://abc.xyz/b
Connecting to abc.xyz (150.150.150.150)
(Nothing happens)

I simply cannot figure out where the problem is. Is it in traefik or is this a docker limitation?

Answer 1

After some more research I found out that it wasn't related to docker or traefik at all. The host linux had a firewall enabled ( ufw ) that was blocking the requests from the docker containers, since it wasn't configured properly.

I now allowed access from the containers and it works.