Connect to a host socket from a docker container

Question

I have the following docker container

FROM ubuntu:16.04
RUN apt-get update && apt-get install -y curl net-tools netcat nmap
CMD /bin/bash

I run it with volume /tmp mapped

From host, I created a socket inside /tmp . I tested with ncat and the connection works from host. However, it does not work from the docker container.

ncat -U /tmp/uwsgi.sock
Ncat: Connection refused.

How could I achieve this?

Permissions:

$ ls -al /tmp/uwsgi.sock
srwxrwxrwx  1 user  wheel  0 Jun 19 23:53 /tmp/uwsgi.sock

Answer 1

Ncat: Connection refused. means peer side has close the connection, so you in container cannot link to it.

One example for you:

docker host part:

shubuntu1@shubuntu1:~$ ncat -lU /tmp/test.sock
hello
world

command to lunch container with another ssh session:

shubuntu1@shubuntu1:~$ docker run -it -v /tmp:/tmp ubuntu /bin/bash

container part:

root@01f724409cec:/# apt-get update && apt-get install -y curl net-tools netcat nmap
root@01f724409cec:/# ncat -U /tmp/test.sock
hello
world

You can see on any side when you input hello , world , another side could see it too.

But if close the unix socket on docker host side:

shubuntu1@shubuntu1:~$ ncat -lU /tmp/test.sock
hello
world
^C
shubuntu1@shubuntu1:~$

Then again connect it in container side:

root@01f724409cec:/# ncat -U /tmp/test.sock
hello
world
^C
root@01f724409cec:/# ncat -U /tmp/test.sock
Ncat: Connection refused.

It will show Connection refuesd .