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nginxdocker
TomG
TomG

Reputation: 2539

Docker Nginx disable default exposed port 80

Is there a way to disable the default EXPOSE 80 443 instruction in the nginx docker file without creating my own image?

I'm using Docker Nginx image and trying to expose only port 443 in the following way:

docker run -itd --name=nginx-test --publish=443:443 nginx

But I can see using docker ps -a that the container exposes port 80 as well:

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                                     NAMES
ddc0bca08acc        nginx               "nginx -g 'daemon off"   17 seconds ago      Up 16 seconds       80/tcp, 0.0.0.0:443->443/tcp              nginx-test

How can I disable it?

Upvotes: 6

Views: 8680

Answers (4)

Guido U. Draheim
Guido U. Draheim

Reputation: 3271

You don't need to patch the original dockerfile then rebuilding the image. You can just edit the image's metadata to unexpose the port. See https://github.com/gdraheim/docker-copyedit

Upvotes: 0

Emilio
Emilio

Reputation: 2752

There is a workaround to free the port (but not to unexpose it). I tried avoiding to publish the port but it didn't work and I got errors about the por being already in use anyway. Until I found that the trick is to publish the exposed port but mapped to a different one.

Let me explain with an example.

This will still try to use port 80:

docker up -p 443:443

But this will use 443 and some other random port you pick

docker up -p 443:443 -p<some free port>:80

You can do this in your commands, docker-compose or ansible playbooks to be able to start more than one instance on the same machine. (ie: nginx, which exposes port 80 by default)

I do this from docker-compose and ansible too.

Upvotes: 0

Farhad Farahi
Farhad Farahi

Reputation: 39507

The expose instruction is in the docker file which the image is built from. You need to create your own customized Image for that.

To get the job done: First locate the dockerfile for the official nginx (library)

Then Edit the dockerfile's expose instruction to 443 only.

Now build your own image modified image using official(customized) dockerfile.

To answer your edited question:

Docker uses iptables, While you could manually update the firewall rules to make the service unavailable at a certain port, you would not be able to unbind the Docker proxy. So port 80 will still be consumed on the docker host and docker proxy.

Upvotes: 3

Joaquin Javi
Joaquin Javi

Reputation: 876

according to nginx docker image configuration , you can set this before container starts passing an environment var like : 

docker run -itd -e NGINX_PORT=443 --name=nginx-test nginx

see :

using environment variables in nginx configuration

then in your nginx you can set :

listen ${NGINX_PORT};

Upvotes: 0

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