[CentOS] PostgreSQL port accessible even though it should be blocked by firewall

Mon Oct 29 19:43:42 UTC 2018
Keith Keller <kkeller at wombat.san-francisco.ca.us>

On 2018-10-29, Frank Thommen <list.centos at drosera.ch> wrote:
>
> PostgreSQL is running in a docker container:
>
> $ docker ps
> CONTAINER ID        IMAGE                         COMMAND 
>    CREATED             STATUS              PORTS                    NAMES
> 6f11fc41d2f0        postgres                  "docker-entrypoint..."   4 
> days ago          Up 4 days           0.0.0.0:5432->5432/tcp   postgres
> $
>
> The various docker interfaces and virtual bridges are not assigned to 
> any specific zone.
>
> Why is port 5432/tcp open?

It may be Docker manipulating the iptables rules.  If you don't want it
open at all, remove the port argument from the docker run command line
(or moral equivalent) and recreate the container (make sure you have
saved your data first, either with a volume mount or by dumping first).

If you need something more complex, here's some docs on how Docker
interacts with iptables, and how you can insert rules into its chains:

https://docs.docker.com/network/iptables/

--keith


-- 
kkeller at wombat.san-francisco.ca.us