Weird port occupied issue with Docker container



Dear all,

I’m running test with my docker container under circleci, one of my services in docker container will use 9010 port. When I mount the docker container with

docker run -d --name mycontainer -p 9010:9010 my/dockerimage

and then go inside container before launch my service, with cmd

netstat -ap | grep :9010

it shows

root@940963d# netstat -ap | grep :9010
tcp6       0      0 [::]:9010               [::]:*                  LISTEN      - 

the port is occupied, thus my service cannot run. Tested with other port with my service, it runs ok. Any inside for such issue ? Thank you in advance.


when I run same docker image locally, there is such issue.



Can you show us any related error logs? I tried this on a base Ubuntu container with port 9010 and 9595 (just for completeness) and no problems with either. Within the CI environment (the LXC container), netstat showed the port binded by Docker, which is expected. Within the Docker container, netstat showed nothing as I would running bare container.


Dear Fellclano

Under my SSH debug environment, I run

docker  run -d --name tmp4 -p 9012:9012 ubuntu:14.04.4 tail -f /dev/null

and get inside container

sudo lxc-attach -n "$(docker inspect --format '{{.Id}}' tmp4)" -- /bin/bash


netstat -ap | grep :9012

it shows

root@8ac854be9af5:/# netstat -ap | grep :9012
tcp6       0      0 [::]:9012               [::]:*                  LISTEN      - 

testing on another non-mapping port, ex: 9015, it shows nothing, that is ok.


And, yes as you said, when I use general ubuntu (without tag)

docker  run -d --name tmp4 -p 9012:9012 ubuntu tail -f /dev/null

everything is ok, so the problem is just conflict with

  • ubuntu:14.04
  • ubuntu:14.04.4
  • ubuntu:15.10

since my docker image is based on that. And the current ubuntu:latest is based on ubuntu:16.04