Getting 'ERR_CONNECTION_REFUSED' when trying to browse port mapped to Docker container

Question

I have pulled a Docker image:

$ docker pull ghost

And run a container from the image:

$ docker run --name test-ghost -p 8080:2368 -d ghost
7d984e974f6a75fe18b3d397b5c8f0a428928a2be9df83f0d61a679aa5f537fc

My understanding is that the -p switch will map a port on the host (8080) to a port inside Docker (2368), so that I can hit the web server running within Docker, from outside docker, i.e. from my host.

However, when I try to browse to any of the following addresses in Chrome, from my host:

http://localhost:8080/
http://0.0.0.0:8080/
http://127.0.0.1:8080/

I get the following error:

This webpage is not available

ERR_CONNECTION_REFUSED

This seems like it might be a connectivity issue, rather than a problem inside the container, as when I inspect the running processes inside the container, it appears that NodeJS is running:

$ docker top test-ghost
UID          PID           PPID      ...  CMD
docker       4290          1028      ...  npm
docker       4324          4290      ...  sh -c node index
docker       4325          4324      ...  node index

But it appears nothing is listening on port 8080:

$ sudo lsof -n -i4TCP:8080 | grep LISTEN
$

I also checked and my MacOS firewall is turned off.

---

I don't expect a full solution here, as I'm aware the information I've given is minimal.

What I'm wondering is, how would one go about fixing such a problem?

It seems that the Docker port is unaccessible.

Is there some way of finding out why the port mapping didn't work? Or what ports are being exposed by Docker? Perhaps I'm mapping the wrong internal port?

Or are there any other general suggestions as to what I might be doing wrong here?

Solution 1

Finally figured out how to make this work!

I'm running Docker on MacOS and using 'Docker QuickStart Terminal'.

Turns out, navigating to 'localhost', '127.0.0.1', etc. was wrong, because it looks like Docker sets up its own host:

                        ##         .
                  ## ## ##        ==
               ## ## ## ## ##    ===
           /"""""""""""""""""\___/ ===
      ~~~ {~~ ~~~~ ~~~ ~~~~ ~~~ ~ /  ===- ~~~
           \______ o           __/
             \    \         __/
              \____\_______/


docker is configured to use the default machine with IP 192.168.99.100
For help getting started, check out the docs at https://docs.docker.com

When I use 192.168.99.100, given above, everything works fine.

Solution 2

To find out the IP address of the running container, you can use:

docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' myContainerID

Comments

[user9517]

Possible duplicate of What causes the 'Connection Refused' message?

[Gautam]

Note - make sure you use the same port in both docker and published fields. Otherwise some links in the ghost site won't work such as home since they are bound to the docker port.