Docker: Error starting userland proxy: Bind for 0.0.0.0:50000: unexpected error Permission denied on Azure VM

Question

I'm new to Docker so please be kind but I am testing it out on a Windows 10 image on Azure (I know I could run it directly but I wanted to try it in a VM first).

I have a fresh Windows 10 image that I have installed Docker for Windows 2.0.0 on. Note: I did not tick the option to use Windows containers instead of linux containers.

Once it installed (and rebooted) I was prompted to install Hyper-V and Containers features (causing restarts).

Once it was all installed I open an Administrative PowerShell window to download Jenkins:

docker run -p 8080:8080 -p 50000:50000 -v jenkins_home:/var/jenkins_home jenkins/jenkins:lts

This gave me the error:

C:\Program Files\Docker\Docker\Resources\bin\docker.exe: Error response from daemon: driver failed programming external connectivity on endpoint goofy_lederberg (deaba2deeea0486c92ba8a1a32740295f03859b1b5829d39e39eff0b24613ebf): Error starting userland proxy: Bind for 0.0.0.0:50000: unexpected error Permission denied.

I thought this was strange as 50000 wasn't a port that I expected to be in use, changing this to different ports (50001) produced the same error.

Running:

netstat -a -n -o

Showed that the port was not in use.

If I remove -p 50000:50000 from the command it can bind and start Jenkins but I assume it needs this port mapping to work correctly.

Previous posts have suggested stopping the World Wide Web Publishing service but that isn't installed.

There are no other running Docker containers.

I assume the port is in use or something is stopping the port mapping.

Assuming a user has permission to create a port binding from their terminal are there any other techniques beside netstat to determine if something is bound to a port - either something internal to docker's own checking process or something at the host OS level?

Answer 1

Rather embarrassingly this worked this morning with no changes other than the VM was shutdown over the weekend. Maybe all it needed was a reboot?