Introduction
The easy part of writing an application is that it is typically the writing part. The real challenge comes when it’s time to get it running smoothly on a server. A missing dependency, an outdated package or a different system configuration can easily make a successful build a failed deployment.
Docker addresses this by bundling up your application with all that it requires to function. You can also deploy Docker on a VPS and have complete control of the server, which will make it simpler to handle, update, and scale your applications without worrying about variations between environments.
What Is Docker?
Docker is an open-source platform for packaging an application, its dependencies, and configuration into a container. A container is an isolated environment in which your application runs without interference from the rest of the system, which helps it behave in the same way when deployed anywhere.
Docker is used by developers for its ease of deployment. They can build an application once and run it across environments with minimal changes as opposed to setting up each server individually. If you’re new to Docker, learn more about what Docker is and how it works before setting it up on a VPS.
Some of Docker’s biggest advantages include:
- Delivers consistent performance across different environments
- Makes moving applications between servers quick and simple
- Speeds up deployment, testing, and updates
- Uses system resources more efficiently than traditional virtual machines
Why Use a VPS for Docker?
A VPS will allow you to use Docker without restrictions, whereas a shared host will have its own limits. A VPS offers dedicated resources such as CPU, RAM, storage, and root access, giving you the flexibility to set up the server according to your application requirements.
A VPS allows you to install Docker Engine, create custom networks, manage containers and allocate resources without any restrictions, unlike shared hosting where many system-level settings are limited. For those looking to run websites, APIs, or production workloads, a VPS will provide the performance and flexibility to make the most of Docker.
Before You Install Docker
Before starting the installation, make sure your server is ready.
- Ubuntu 22.04 LTS or later.
- Access to your VPS via SSH.
- A user account that has the sudo privilege.
- The latest system updates have been installed.
- A reliable internet connection.
How to Install Docker on Ubuntu VPS
Installing Docker on Ubuntu is easy. Follow the four steps below to prepare your server for running containers.
Step 1: Update Your System
Update the package list and install any updates prior to installing new software.
Run the following commands to update the package list and upgrade the packages:
Step2: Install Docker Engine
Docker is available in the default repositories of Ubuntu, and you can install Docker Engine by using a single command.
sudo apt install docker.io -y
Step 3: Start and Enable Docker
To get Docker running, follow these steps:
Run the Docker service and make sure that it starts up automatically when your VPS restarts.
sudo systemctl enable --now docker
Step 4: Check the installation.
Verify the version of Docker installed to ensure proper installation.
docker --version
If the command shows the version installed, Docker is now ready to use on your VPS.
Dockerfile, Image, and Container Explained
When you’re new to Docker, the Dockerfile, Docker Image, and Docker Container terms may be confusing. The best way to explain them is to think of building a house.
A Dockerfile is similar to the building plan. It includes instructions to set up the environment your app requires.
A Docker Image is the finished house that is created from that plan. It contains your application, its requirements, and all you need to run it, but no one is running it.
A Container is what you get when someone moves into that house. It is the running version of the Docker Image in which your application is running.
| Component | Purpose |
| Dockerfile | Defines the steps needed to build a Docker image. |
| Docker Image | A packaged application with all required files and dependencies. |
| Container | A running instance of a Docker image. |
Understanding this sequence makes Docker much easier to follow: create a Dockerfile, build an image from it, and run that image as a container.
Run Your First Docker Container
With Docker installed, you can launch your first container in just a few commands.
Pull the Nginx image
docker pull nginx
Run the container
docker run -d --name my-nginx -p 80:80 nginx
This command starts an Nginx web server in the background and makes it available through port 80 on your VPS.
Check that it’s running
docker ps
If your container appears in the list with the status Up, your first Docker container is running successfully.
Why Docker Volumes Matter
The intent of containers is that they are temporary. Any data in a container is deleted when the container is deleted. Docker Volumes store data outside the container, which means that it will not disappear when you update or replace the container. They are crucial for applications that store critical data, like WordPress websites, where media files must be stored, or databases like MySQL and PostgreSQL, which require persistent storage.
Docker Commands Every Beginner Should Know
- docker ps – Displays all running containers.
- docker images – Lists the images on your system.
- docker stop <container> – Stops a running container.
- docker start <container> – Starts a stopped container.
- docker logs <container> – Shows the logs generated by a container.
- docker rm <container> – Remove a stopped container.
Best Practices for Docker on a VPS
- Update Docker Engine to get the latest security patches and improvements.
- Use trusted or official repositories to download images when possible.
- Regularly back up Docker Volumes to prevent loss of important application data.
- Avoid running containers as the root user unless it’s absolutely necessary.
- Keep an eye on CPU, memory and disk usage to ensure a stable system.
- Periodically delete unused images and containers to free up storage.
Conclusion
With Docker, you can deploy your applications with greater confidence, knowing that they will behave the same way in various environments. Using Docker with a VPS allows you to have a full control over your server, which makes it simpler to deploy, manage and scale your containerized applications. Whether you’re developing or deploying, Cantech VPS offers full root access, swift SSD storage, and scalable resources for building and deploying with confidence.
FAQs
Can Docker run on every VPS?
Docker is compatible with most Linux VPS servers, such as Ubuntu, Debian, CentOS, Rocky Linux, and AlmaLinux. You can install and use it without any problems as long as your VPS has the necessary system requirements and provides you enough administrative access to install and use Docker.
What’s the difference between Docker Engine and Docker Desktop?
Docker Engine is the basic software used to run and manage containers on Linux servers. Docker Desktop is a combination of Docker Engine with a graphical interface and additional developer tools for Windows and macOS. If you have a Linux VPS, you should use Docker Engine.
What is a Docker Image?
A Docker Image is a pre-built package containing your application, its dependencies and the environment needed to run your application. All containers are based on an image, providing consistency of deployments across different systems.
Why are Docker Volumes important?
Docker Volumes are data stored outside the container and not lost when the container is updated, removed or recreated. They are typically used for databases, WordPress websites, and anything that requires storing data for the long term.
Can I use Docker without a VPS?
Absolutely. Docker is available on your personal computer and is great for local development and testing. A VPS is beneficial if you are ready to host your applications online, require dedicated resources, complete control, and reliable performance.
