Here are 5 reasons that you should be using Docker on your home automation server.
This applies whether you are running your home automation software stack on a bare metal server, a Raspberry Pi, an old laptop, or just about any other device.
What Is Docker
Docker is a containerization platform. It allows you to run multiple applications on the same computer without them interfering with each other. It also allows you to quickly try out new software without having to worry about breaking your existing setup.
Docker is similar to a virtual machine. However, it is much lighter weight and more efficient. It is also much easier to set up and use.
Software that runs in Docker is said to be running in a container. A container is a self-contained unit of software that includes everything it needs to run. This includes the operating system, libraries, and base configuration files. Your personal configuration files are stored outside the container.
Docker Images and Containers
Docker images are the templates that are used to create containers. They are similar to virtual machine images. They are the starting point for your container. You can think of them as the software that you want to run.
Docker containers are the running instances of your Docker images. They are similar to virtual machines. They are the actual software that is running on your computer.
When you download and run software using Docker, someone else has already created a Docker image for you. You don't have to create your own Docker images unless you want to. This makes it easy to get started with Docker.
Try Out and Discard New Software
Docker makes it easy to try out new software without having to worry about breaking your existing setup. You can run the new software in a container and test it out. If it works, you can keep it. If it doesn't work, you can just delete the container and try something else.
Installing new software using Docker is as simple as running a single command. You don't have to worry about dependencies, configuration files, or anything else. You just run the command and it works. The person who created the Docker image has already taken care of all of that for you.
When you delete a Docker container it is gone forever. It does not leave any files behind on your computer. This makes it easy to try out new software without having to worry about breaking your existing setup.
Prevent Conflicts Between Different Versions of Home Automation Software
Some software packages require specific versions of other software packages. This is called a dependency. If you install a new version of a software package that has a dependency on a specific version of another software package, it may break your existing setup. This is especially true if you are running multiple versions of the same software package.
For example, there have been times recently that Home Assistant required a specific version of Python. If you install a newer version of Python, Home Assistant may stop working.
At the same time another common home automation application called AppDaemon required a different version of Python. These created a situation where it was difficult to run both Home Assistant and AppDaemon on the same computer.
Of course, since Home Assistant and AppDaemon are both written in Python you can solve this problem with Python virtual environments. However, this is an additional step that you have to remember each time you update either one, and it is easy to make a mistake. Docker makes it easy to run multiple versions of the same software package without having to worry about dependencies.
Keep Your Home Automation Software Up-to-Date
Docker makes it easy to keep your home automation software up-to-date. Since a Docker container does not contain any of your personal configuration files, you can easily delete the container and create a new one from the newest image. This will install the latest version of the software, while your configuration files will remain the same.
The Docker engine is designed from the ground up to make it easy to update your software. Images are downloaded in layers. This means that if you update a single layer of an image, only that layer needs to be downloaded. This makes it easy to update your software without having to download the entire image again. Most image updates are very fast to download.
You can even set up a cron job to automatically update your Docker containers every day. This will ensure that you are always running the latest version of your home automation software.
Keep All of Your Configuration Files in One Place
When you launch a docker image, you specify a directory on your computer to store your configuration files. This directory is called a volume. You can think of it as a folder that is shared between your computer and the Docker container.
The volume lives on your bare-metal server in a real directory that can be backed up, moved around, and restored. This makes it easy to keep all of your configuration files in one place. You can even use a cloud storage service like Dropbox to keep your configuration files in sync across multiple computers.
Since the configuration files are in your real server on a real directory, you can use your text editor of choice to edit those files. Usually you have to stop the container, edit the configuration files, and the start the container back up again. However, some Docker images have a feature called hot reloading. This means that you can edit the configuration files while the container is running and the changes will be automatically applied.
In addition, Docker containers usually start very fast, so you can stop and start them as often as you want.
Move Your Home Automation Server to a New Computer
Since all of your configuration files are stored in a real directory on your bare-metal server, you can easily move your home automation server to a new computer.
Simply stop the Docker container, move the configuration directory to the new server, and then fire up a new container from the same image. This will install the same version of the software that you were running on the old server, and it will use the same configuration files.
If you use a cloud storage service like Dropbox to keep your configuration files in sync across multiple computers this process is even easier. You can just copy the configuration files from your old computer to your new computer and then fire up a new container from the same image.
Learn How to Install Docker 4 Different Ways
Now that you are ready to give Docker a try, you can learn how to install it 4 different ways in the next article.
Whether you have Unraid, Proxmox, a NAS, or a bare-metal server, there is a way to install Docker on it.