Docker comes as a light weight server solution. And, that makes it even more popular.

But, does Webmin support Docker ?

Yes. Luckily, Webmin docker module make things easier for Docker lovers.

But, setting up Docker containers in Webmin involves a series of steps.

That’s why, customers often contact Bobcares Engineers to integrate Docker to Webmin as part of our Technical Support Services.

Today, we’ll see how our we make Webmin Docker module working on the server.

Why Docker?

Before proceeding further, let’s see why many users rave about Docker.

Docker provides a quick option to create multiple replicas of build, test, and production environments. This comes really handy in development work. Additional advantages like isolation of apps, security features, etc. makes it even more popular. Similarly, Docker can work in multiple platforms like AWS, Google Cloud, etc.

Above all, Docker comes as an open source platform too. Therefore, it’s really nice to have Docker support on Webmin as well.

How to setup Docker containers in Webmin?

Till now we saw the major benefits of Docker. But, it involves a series of steps to enable Docker container in Webmin.

We’ll now check these steps in detail.

1. Setup Docker Host

Firstly, we need to set up a docker host. Here, our Dedicated Engineers ensure that this server contains all the tools needed to run containers. Mostly, we choose the server as Ubuntu as it readily works with the Docker setup. But, if customer need a different server type, we first ensure that it supports Docker system.

As the next step, we install Webmin on the Host system.

2. Enable Docker Host system

Secondly, we need to setup the Docker Host System. For this, we add the host system to Cloudmin panel at Add System -> Add physical system. When it is added properly, it will list under the option Docker Host Systems.

After this step, its time to add the Host. We do it from Host Systems -> Docker Host Systems -> Host System name ->  Start Adding Host

Here, we set up the DNS domain of the new systems too.

We finish the process by registering at the Docker Hub account section using the customer’s Docker Hub account login details.

3. Using Docker images

Now, its time to create the Docker images. Docker containers can be created only from Docker’s own native images. These images should be present in the host systems itself.

Docker images are publicly available at Docker Hub. This has access restriction and we need to use Docker Hub login details to download the images.

So to create a Docker container, our Dedicated Engineers first download the image to the Host System. For this, we access the Cloudmin panel -> Docker -> Search Docker Images. Then we download the desired image using Download Images To button.

Once we have the image, container creation becomes really easy. Additionally, Cloudmin allows customization on the image for future use too.

Common Docker related errors and fixes

Although, the steps to setup Webmin Docker module looks easy, we often see users having problems with the setup process.

Let’s now see the top problems and their fixes.

1. License and Docker support

Recently, one of our customers reported problems with adding a Docker Host System. Unfortunately, he was not able to see the option Add System -> Add physical system in his Cloudmin panel.

On checking, we found that customer was on Cloudmin GPL license. Unfortunately, that was the reason for the missing option. Cloudmin GPL only supports a single system.

Here, to fix the problem we had to work with customer to upgrade the Cloudmin license.

2. Application errors

Similarly, there can be application errors with in the docker containers too. This happens mainly because of reasons like unsupported operating system, lack of driver support, etc.

In such cases, the error will look like:

Building app
which: no docker.io in (/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin)
Your Docker installation is not using a supported storage driver. If we were to proceed you may have a broken install.

To fix, our Dedicated Engineers install the correct driver package. Here, we also double check the installation requirements too. For example, for installing Discourse Docker image, we need an Ubuntu container. And, trying to setup it on a different OS can result in errors. Therefore, choosing the right server type is really critical.

[Need help with creating Docker in Webmin? We are here to help.]

Conclusion

In short, Webmin Docker module makes Docker creation and management an easy task. Today, we saw how our Support Engineers create Docker container in Webmin servers and fix typical errors with it.