Failed to add additional docker host

I am running cloudmin pro 9 on a centos 7 built less than a week ago.
name of my master system is called cloudmin-master
I was able to add a physical system using ssh keys. Name of this system is cloudmin-pod1.

On cloudmin-master I was able to add that system as a Docker Host System by navigating to
> Host Systems > Docker Host Systems.

When I try and add cloudmin-pod1 as an additional Docker Host System I receive the error message:

Failed to save Docker host:

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The error in /var/webmin/minserv.error says the following:


(not a typo that is all it says)

I was able to login to cloudmin-pod1 navigate to
> Host Systems > Docker Host Systems
and add cloudmin-pod1 as a Docker system moving back to cloudmin-master didn't change anything in terms of being able to add a second system as a docker eligible system.

Any idea how this is supposed to work? Thanks.


Closed (fixed)


Can you add the line error_stack=1 to /etc/webmin/config , try adding the host again, and post the full error message?

Failed to save Docker host :

Call Stack Trace

File Line Function
/usr/libexec/webmin/server-manager/save_docker.cgi 29 WebminCore::error
(eval 53) 6 (eval)
/usr/libexec/webmin/ 2392 (eval)
/usr/libexec/webmin/ 914 miniserv::handle_request

Thanks - the problem here is that the docker host doesn't have Webmin installed, which is required by Cloudmin. This can be done by easily from within Cloudmin, using the System Operations -> Install Webmin link on the left menu.

Thanks for this. I had already installed cloudmin/webmin on this system as a result of running the same install script that I ran on the master system. I failed to connect it the master system using port 10000 which I guess is a requirement.

After connecting to the pod system using webmin I was able to add a second docker host.

Now if I could only get these system to start a docker image from the gui I think we would a lot further ahead. Thanks.


Right, if the master cannot connect to the second host on port 10000 then it isn't going to work. If you have any firewall in place, you'll need to open that up.

Thanks the two are now connected and can see each other.

Great - I will make this error message clearer in future.

Status: Active ยป Fixed