prevent Docker from exposing port on host

Question

If i start a container using -p 80 for example, docker will assign a random outbound port.

Everytime Docker assign a port, it also add an iptable rule to open this port to the world, is it possible to prevent this behaviour ?

Note : I am using a nginx load balancer to get the content, I really don't need to have my application associated with two different port.

zero323 · Accepted Answer · 2015-07-12T12:10:21.677

2

You can specify both interface and port as follows:

-p ip:hostPort:containerPort

or

-p ip::containerPort

Another solution is to run nginx inside container and to use conteiner linking without exposing other services whatsoever.

edited Jul 12 '15 at 12:10

answered Jul 12 '15 at 11:12

zero323

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is it possible to do -p127.0.0.1:1234 to get a random assigned port ? – Dimitri Kopriwa Jul 12 '15 at 11:53
You can use `ip::containerPort`, I've updated an answer. – zero323 Jul 12 '15 at 12:10
I am running nginx inside container btw, but still if i expose like "ContainerPort", the randomHost port got open to the world – Dimitri Kopriwa Jul 12 '15 at 12:14

score 0 · Answer 2 · answered Jul 12 '15 at 21:41

0

The iptable feature is a startup parameter for the docker demon. Look for the docker demon conf file in your docker installation. Add --iptables=false and docker never touches your iptables.

answered Jul 12 '15 at 21:41

blacklabelops

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prevent Docker from exposing port on host

2 Answers2