Docker Desktop for Windows: cannot access service on exposed port in windows container mode

Question

I am using the following Dockerfiles to create a container running Jenkins in a windows container on Windows 10 desktop running Docker Desktop for Windows version 17.03

FROM microsoft/windowsservercore

RUN powershell -Command wget 'http://javadl.oracle.com/webapps/download/AutoDL?BundleId=210185' -Outfile 'C:\jreinstaller.exe' ; Start-Process -filepath C:\jreinstaller.exe -passthru -wait -argumentlist "/s,INSTALLDIR=c:\Java\jre1.8.0_91" ; del C:\jreinstaller.exe

ENV JAVA_HOME c:\\Java\\jre1.8.0_91  
RUN setx PATH %PATH%;%JAVA_HOME%\bin

CMD [ "java.exe" ]

I create the image from this docker file:

docker build -t windows-java:jre1.8.0_91 .

The second Dockerfile I am using to install Jenkins on top of this:

FROM windows-java:jre1.8.0_91

ENV HOME /jenkins  
ENV JENKINS_VERSION 2.58  
RUN mkdir \jenkins  
RUN powershell -Command "wget -Uri https://updates.jenkins-ci.org/latest/jenkins.war -UseBasicParsing -OutFile /jenkins/jenkins.war"

EXPOSE 8080  
EXPOSE 50000  

CMD java -jar C:\\jenkins\\jenkins.war


docker build -t jenkins-windows:2.0 .

Then I launch the container like this:

docker run --name jenkinsci -p 8080:8080 -p 50000:50000  jenkins-windows:2.0

I can see the container running fine and logs showing up all good

PS C:\Users\mandeep\ringba\ringba-jenkins-setup-windows\jenkins-master> docker ps
CONTAINER ID        IMAGE                 COMMAND                  CREATED             STATUS              PORTS                                              NAMES
85ba2ef525a1        jenkins-windows:2.0   "cmd /S /C 'java -..."   8 hours ago         Up 8 hours          0.0.0.0:8080->8080/tcp, 0.0.0.0:50000->50000/tcp   jenkinsci

However, I cannot access the jenkins server running on http://localhost:8080 on the host machine's web browser.

Not sure if it helps but when I was running docker in Linux container mode on the same machine, I was able to access jenkins server on http://localhost:8080 using their official docker image.

Answer 1

This is a currently a known issue on Windows. It's not possible to access a container endpoint from its own host using localhost/127.0.0.1. It is possible using Linux containers today because Docker has included a special workaround that is unique to their Moby/Linux implementation for running Linux containers on Windows.

We're working on a fix for this, but today we recommend working around this by either:

• Accessing container endpoints from a separate host, using the IP address of the host that is running the container, and the exposed port for the container on its host
• OR by accessing the container on the same host, using the container's internal IP address and published port (you can use docker network inspect <network name> or docker exec <container ID> ipconfig> to get the IP address of the container endpoint itself)