Running the server inside a container

[pocsuka]

Hello,

I have an issue making calls to the server, if it runs inside of a docker container. I hope you might be able to help solving this issue.

In my project the docker img basically contains only the executables.

The Dockerfile is the following:
FROM debian:stable-slim
WORKDIR /app
ADD . .
CMD ["./my_exe"]
EXPOSE 9000

Whit this Dockerfile but with a different server library, I was able to make api calls to the server.

Simply just running the exe, I can make api calls to the server, but if it runs in a container I don't have any success.
If I am inside of the container, I am able to make curl calls to the server, and it works fine.

I have absolutely no idea what can be the issue.

Thanks in advance.

Best regards,
David

[jchristn]

Hi @pocsuka could you try using the dockerfile in the Test.Docker project and let me know the result? https://github.com/jchristn/WatsonWebserver/tree/master/Test.Docker

[jchristn]

Hi, understood, sorry to send it so early your time. Since the listener will need to listen for requests on any hostname, you'll need to specify the listener hostname of *, +, or 0.0.0.0. Doing so requires that the process run under elevated privileges (this is an OS limitation, not a Watson limitation).

For my case, I had to use --user root in my docker run statement.

docker run --user root -p 8080:8080 watsontest

[pocsuka]

It's working!
I had to check it before I go to sleep :D
Big thanks, really

[jchristn]

That's awesome to hear! I'm going to close this out - please reopen if any more issues :)

[jchristn]

Hi @pocsuka I would be remiss if I didn't tell you that running the process as root within the container introduces some security concerns. You really shouldn't run it as root, it's just an easy way to get the HTTP server to "listen for anything" (i.e. *, +, 0.0.0.0, etc).

Ideally you'd specify an IP address or hostname on which it would listen, and make sure that the container routing forwarded requests to the webserver using that specific hostname. One of the drawbacks of anything using Windows http.sys (like Watson) is that, unless you're using */+/0.0.0.0, the HTTP HOST header of the incoming request MUST match exactly the listener prefix.

So, net-net, use root at your own risk. I'd definitely recommend finding out what HOST header is supplied on incoming requests, and set your listener in Watson to use that instead of */+/0.0.0.0.

Cheers, Joel

[pocsuka]

Thanks for the information.

Our service will run in an internal network and we also authenticate every request, so I think running the container with root should be okay, but the DevOps guys might think differently :D