Connection from docker container to host (access OMV webui from muximux)

I'm currently doing some test with the docker plugin.

I'm trying to run the muximux image from linuxserver.io. I managed to get it up and running. My problem is to point to my sickrage web ui.
I cannot find which ip address I must use. Trying the localhost didn't work, neither using the docker0 ip adress (something like 172.17.0.1).

How you guys make your apps running in container, connect to another application installed locally on the host (accessible normally via OMV_IP:port).
Is that a firewall problem?

Ok, I think I did'nt make myself really clear.
My web-app is up and runing in a container in bridge mode, necessary ports are forwarded, so I have no problem to reach the web ui of the app. My problem was the current web-app, need to connect to other web-apps running natively on the host. And as of yet, I couldn't figure out which ip address i had to use.

After further test, I discovered that the only problem I have, should be specific to muximux. Muximux is a kind of proxy page for all the web-app like sickbeard, couchpotato, headphones...that is configurable, so you can add anything (based on url) to the page.
Its working perfectly with sickbeard using local address of server (192.168.X.X).
I cannot add the OpenMediaVault webui though, and I think it has to do with SSL being enabled for this one...still digging info, but if you are user of muximux...

EDIT : that has to do with the Content Security Policy of the webui of OMV.
The only thing possible is to install a plugin that tells your browser to simply ignore any Content-Security-Policy settings that websites try to set (though that is typically bad to do).... I've checked and it works with that kind of plugin. Running muximux with ssl doesn't change this. Guess I will just use it for other web-app. I don't need to access OMV webui that often.