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A Docker container alone does not solve the operational challenges: you also need a VPS that is configured appropriately. Using Docker on a VPS becomes predictable when the server’s resources match the application’s requirements, and you manage access and network ports carefully.
You may be wondering what size of Linux VPS is sufficient, how to install Docker, and how to start and update containers securely. In this guide, we’ll walk you through server selection and basic configuration, then outline the main steps for launching and maintaining applications.
We’ll be discussing the use of Docker Compose, restricting open ports, managing permissions and selecting reliable container images. This will help you create a more transparent Docker environment on a Linux VPS and make it easier to keep track of application updates and server security.
Using Docker on a VPS: when is this setup suitable?
Docker packages applications and the dependencies required to run them into isolated containers. This allows the application and its environment to be installed together, which facilitates consistent operation across development, testing and production environments. An overview of Docker’s principles helps to understand how it makes containerised execution more portable.
A VPS is a virtual server environment in which you can manage the operating system, install the components required for Docker, and configure applications. A Docker container is not a separate virtual server: it isolates the application and its dependencies from other processes, whilst utilising the resources of the VPS’s operating system. Using Docker on a VPS may therefore be suitable if server-side control and a repeatable installation process are important to you.
Typical use cases:
- Web application: the application and the components required to run it can run in separate containers.
- Database: can be launched in an isolated environment, and long-term data storage must be configured to preserve the data.
- Development environment: pre-configured dependencies help to ensure greater consistency in the development and testing environments.
How do Docker containers differ from virtual machines?
A virtual machine runs its own guest operating system on top of the virtualisation layer. A container, on the other hand, does not contain a separate operating system kernel, but uses the kernel of the VPS system. Both provide isolation, but in different ways: a virtual machine provides a complete operating system environment, whilst a container primarily isolates the application and its dependencies. Launching containers generally requires fewer system resources, but this also depends on the specific application and the configuration.
When should you choose a VPS for Docker?
Docker and VPS can be good choices if you want to run multiple services in isolation, or if you wish to reuse the same configuration across installations. A VPS can offer greater server-side control than shared hosting, where you do not manage the operating system settings yourself. However, this means you are responsible for system updates, restricting access, configuring ports and maintaining the containers.
aWh offers Linux VPS and KVM VPS solutions. When choosing the right environment, consider the resource requirements of your application and the operational tasks involved. You can find out more about how virtualisation works on the KVM VPS options page.
Installing Docker on a Linux VPS: preparation and step-by-step guide
Before installation, check that your Linux distribution and its version are included in Docker’s current support list. Debian 13 or Ubuntu 26.04 LTS may be suitable, but always follow the official guide for your specific distribution and release when installing. The commands below are designed for Debian; do not copy them onto other systems without modification.
What should you check before installing Docker?
First, log in to the VPS via SSH and check that you have the necessary administrator privileges. Update the package list and the installed system packages:
sudo apt update && sudo apt upgrade
Next, assess the application’s expected CPU, memory and storage requirements. Also take into account the disk space required for databases and log files. Docker does not remove the resource limits of the VPS, so the environment you choose must be able to handle the application’s full load. Plan your access rights too: use the administrator account only for necessary operations, and keep your SSH login details to hand.
How to install and test Docker?
Set up the official Docker repository on Debian. The following steps will download the repository’s signature key and then add the official stable package source:
sudo apt install ca-certificates curl
sudo install -m 0755 -d /etc/apt/keyrings
sudo curl -fsSL https://download.docker.com/linux/debian/gpg -o /etc/apt/keyrings/docker.asc
sudo chmod a+r /etc/apt/keyrings/docker.asc
echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/debian $(. /etc/os-release && echo "$VERSION_CODENAME") stable" | sudo tee /etc/apt/sources.list.d/docker.sources > /dev/null
Update the package list again, then install the engine, the command-line client and the add-ons:
sudo apt update
sudo apt install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
After installation, start the service, then check the version of the client and the service running in the background:
sudo systemctl enable --now docker
sudo systemctl status docker
sudo docker version
Finally, run the test container: sudo docker run --rm hello-world. A successful outcome confirms that Docker was able to download and start the test image. Do not automatically grant all users access to the Docker service. The OWASP Docker Security Guide is a useful resource for managing permissions securely. When using Docker on a VPS, please also review aWh’s Linux VPS options to select the appropriate Linux environment.
Docker Compose on a VPS: launching applications, ports and data
Docker Compose describes related services, networks and volumes in a YAML file. This allows a web application’s server and database to be started, monitored and stopped from a single configuration. Use the docker compose command, not the old hyphenated docker-compose form. Commands and configuration options may vary depending on the version of Compose you have installed, so please check the latest documentation. Docker best practices provide further guidance on setting up your configuration.
How to manage multiple services using Docker Compose?
The example below describes a web server and a database. Port forwarding only makes the web service accessible on the VPS’s local network interface:
services:
web:
image: nginx:stable
ports:
- "127.0.0.1:8080:80"
adatbazis:
image: postgres
volumes:
- adatbazis_adatok:/var/lib/postgresql/data
volumes:
adatbazis_adatok:
This example illustrates the structure; it is not a complete application configuration ready for a production environment. Before using it in production, record the version of the images and do not write passwords directly into the file.
After saving the file, first check the configuration, then start the services in the background:
docker compose config
docker compose up -d
docker compose ps
docker compose logs -f web
The config command flags configuration errors, ps shows the status of services, and the log helps to identify boot problems. The 8080:80 port mapping can make the port publicly accessible on all network interfaces of the VPS, so only use it when necessary. Keep unnecessary ports closed and only allow essential traffic through the firewall.
How can application data be retained after a restart?
As a container is a reproducible runtime environment, it stores the contents of the database and files uploaded by users on a volume or in appropriately mounted persistent hosting. This means that switching providers does not automatically result in the deletion of data. The docker compose down command stops and removes the containers, but retains the named volumes by default. The docker compose down -v command, however, also removes the volumes, which may result in data loss.
This guide is not a substitute for regular backups. Make sure you back up your data regularly and test the restore process from time to time. Using Docker on a VPS therefore involves not only running applications, but also planning for data preservation and recovery.
Docker on VPS: security, updates and troubleshooting
To ensure the security of your Docker environment, you need to keep the VPS operating system, the Docker Engine and the container images up to date. Using Docker on a VPS is not a one-off installation: regular updates and checks help to reduce the risk of known vulnerabilities, incorrect configurations and unexpected downtime.
What security settings should you check?
Before updating, please read the release notes and create a backup of your application’s persistent data. Then update the system using your Linux package manager, and update the engine and related components from the official Docker repository. For the Compose project, download the updated versions of the images, then restart the services in a controlled manner. For production environments, use a fixed image tag or a controlled image digest to ensure a traceable, consistent installation, rather than the automatically changing latest tag.
Choose images from reliable sources that are regularly maintained, and only grant the container the permissions necessary for it to function. Avoid running as the administrator user, using the --privileged switch, and making the Docker socket accessible to unauthorised users. Access to the Docker socket can effectively grant root privileges on the host machine. Do not store passwords or other sensitive data in publicly shared configurations or source code. Only allow the necessary ports through the firewall and regularly review the rules.
What should you do if a container fails to start?
If an error occurs, follow the troubleshooting steps in order. First, check whether the service is running, then examine the logs:
docker compose ps
docker compose logs --tail=100
If the log indicates a configuration error, check the Compose file and the required environment variables. Then check disk usage, open ports and the VPS load:
df -h
docker system df
ss -tulpn
docker stats --no-stream
A full disk, the port conflict or insufficient memory can all prevent the service from starting. Before updating, check that the backup can be restored. If you’re looking for a suitable server environment for Docker, take a look at aWh’s Linux VPS options and choose one based on your application’s resource requirements.
What sort of VPS do you need for Docker, and how do you get started safely?
There is no single, standard VPS size that is suitable for every Docker application. The choice is determined by the containers you wish to run, the workload of the applications and the amount of data to be stored. Using Docker on a VPS can be planned effectively if you not only take into account the containers’ current requirements, but also allow for changes in the operating system and workload.
How do you assess your VPS resource requirements?
Take stock of the services and their dependencies. The database, web application and background processes all use CPU, memory and hosting. Be sure to factor in the disk space required for logs, databases and uploaded files. Do not rely on estimates to determine your exact resource requirements: measure actual usage during the trial period, even under peak load.
Usage scenarios
A test container: First and foremost, assess the resource requirements of the image and application in question. Also take into account the storage requirements of the Linux system, the Docker service and the logs.
Multiple services: Take into account concurrent load, database performance, persistent storage and the space required for backups. The resource requirements of these services add up and may vary during peak load periods.
Maintaining the system running on the VPS and Docker is also part of the operational tasks. You manage updates, permissions, firewall rules and the backup process. KVM VPS is a type of virtualisation. When selecting the appropriate environment, consider both the available resources and the tasks to be performed.
When is an aWh VPS the right choice?
If you require a Linux-based environment, you’ll find Linux VPS and KVM VPS options within aWh’s VPS range. Check whether the chosen solution suits your workload based on the resource specifications of the selected VPS. The provider supplies the VPS environment, but installing Docker and managing the containers is your responsibility.
What should be the first step in using Docker on a VPS?
Before you start, make a list of the applications and dependencies you’ll be running, the data you need to store permanently, and the services that need to be accessible over the network. Next, choose a VPS that suits your needs, install Docker, and then test the application in a separate test environment. Before switching to production, check that the backup and restore processes are working correctly.
Once you have assessed your resource requirements and operational needs, take a look at aWh’s VPS options and choose a Linux VPS or KVM VPS that suits your intended use.
Get your Docker environment off to a solid start
Using Docker on a VPS works well if the VPS’s resources match the application’s actual requirements and you are prepared to manage the system. Once Docker is installed, Compose helps you start the associated services in a controlled manner, whilst volumes and regularly checked backups ensure data is preserved.
To ensure secure operation, keep your system and container images up to date, limit open ports and grant only the necessary permissions. Test the application before going live, monitor resource usage, and check that restoration from a backup works. A VPS gives you greater server-side control, but maintenance remains your responsibility.
With over 10 years’ experience in the web hosting industry, as well as Linux VPS and KVM VPS solutions, aWh welcomes those looking for a web hosting and server environment from a Hungarian provider. Take a look at aWh’s VPS solutions, assess your application’s requirements, and choose the environment that best suits your intended use.
Frequently asked questions about using Docker on a VPS
What is Docker, and how does it work on a VPS?
Docker runs applications and their dependencies in isolated containers. On a Linux VPS, the Docker Engine manages container images, containers, networks and volumes. A container is not a separate virtual machine; rather, it utilises the resources of the VPS’s operating system. Using Docker on a VPS allows you to run, for example, a web application and a database in separate environments.
How do I install Docker on a Linux VPS?
First, check the support status of your Linux distribution and release in the official Docker documentation. Update your system packages, then set up the official Docker repository for your distribution and install the Docker Engine, the command-line client and the Compose plugin. On Debian, for example, you can use the apt package manager. Start the service, check the output of docker version, then try out the hello-world test image.
What sort of Linux VPS is required to use Docker?
There isn’t a single, fixed VPS size that suits every application. Choose a Linux distribution supported by the latest version of Docker, then assess the CPU, memory and storage requirements of your applications, databases and logging. The resource requirements of a test container may differ from those of multiple services running simultaneously. Monitor the load during the trial period and select your VPS resources accordingly.
Can Docker be used without Docker Compose?
Yes. You can use the docker run, docker stop and other Docker commands directly to create, start and stop a single container. Docker Compose is not mandatory, but it is useful if your application consists of several interconnected services. For example, you can specify the settings for the web application, database, networks and storage volumes together in a single configuration file.
Is it safe to use Docker on a public VPS?
With the right settings, the risk can be mitigated, but Docker alone does not make a VPS secure. Keep your operating system, Docker Engine and container images up to date. Use images from trusted sources, restrict permissions and only make the necessary ports accessible. Do not store sensitive data in publicly accessible source code or shared configurations.
How can you make an application running in a Docker container accessible on the internet?
Set up port mapping between the container’s port and the VPS’s port, then check that the VPS firewall allows the required traffic. For example, the 8080:80 configuration forwards port 8080 on the VPS to port 80 on the container. Only make the necessary ports publicly accessible from the internet; generally, do not make the database directly accessible. For production applications, also configure the domain name and HTTPS settings.
Will my data be preserved if I restart or delete the container?
Restarting the container does not, in itself, delete any data, but data stored in the container’s own writable layer may be lost if you remove and recreate the container. For databases and uploaded files, use a persistent volume or appropriately hosted storage. Commands that remove the volume may result in data loss. Perform regular backups and check that the data can be restored.
When is it better to choose traditional hosting over Docker on a VPS?
Traditional web hosting may be the best option if your website runs in a supported web environment and you do not need to configure your own operating system or run containers. A VPS is useful if you need greater server-side control, customised services or Docker. When choosing a VPS, you will be responsible for maintaining the operating system, Docker, updates and security settings.