Deploy Apps Fast: How to Install Docker on Your VPS

Containers have become the default way to package and deliver modern applications. For webmasters, enterprises and developers running services on VPS instances, installing Docker quickly and correctly is the first step toward faster deployments, consistent environments and scalable architectures. This article walks through the technical principles, practical installation steps on popular Linux distributions, recommended configuration and selection tips for production-ready VPS deployments.

Why Docker on a VPS: core principles and benefits

At its core, Docker leverages Linux kernel features—namespaces, cgroups and union filesystems—to provide lightweight isolation and efficient resource management. Unlike full virtual machines, containers share the host kernel while keeping process, network and filesystem views logically separate. The primary benefits on a VPS include:

• Speed: Containers start in milliseconds, enabling rapid deployment and development cycles.
• Density: More containers can run on the same hardware versus VMs because the kernel is shared.
• Reproducibility: Images encapsulate runtime and dependencies, reducing “works on my machine” issues.
• Portability: Images built locally run identically across dev, staging and production VPS instances.
• Operational simplicity: Declarative tooling (Docker Compose, Dockerfiles) makes configuration manageable and versionable.

Before you install: kernel, cgroups and filesystem checks

Docker expects certain kernel features and a compatible storage driver. Before installation, verify these items on your VPS:

• Kernel version: Docker generally requires Linux kernel >= 3.10, but modern Docker releases and features (like cgroup v2) are best supported on newer kernels (4.15+ or 5.x).
• Cgroups: Determine whether your distribution uses cgroup v1 or cgroup v2. Run stat -fc %T /sys/fs/cgroup or inspect cat /proc/filesystems. Some Docker versions need configuration tweaks for cgroup v2.
• Storage driver support: OverlayFS (overlay2) is the recommended storage driver for most current kernels. Confirm support with grep -i overlay /proc/filesystems.
• Available disk space: Containers and images can consume storage quickly. Prefer SSD-backed VPS with fast I/O and plan the Docker data root (default /var/lib/docker) on adequate capacity.

Installing Docker: step-by-step for common distributions

Below are concise, production-oriented installation instructions. These use Docker’s official repositories so you receive updates and security patches.

Ubuntu / Debian (apt)

Commands assume sudo or root access. Replace $(lsb_release -cs) with your distro codename if required.

• Install prerequisites and GPG key:

sudo apt-get update
sudo apt-get install -y apt-transport-https ca-certificates curl gnupg lsb-release
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmour -o /usr/share/keyrings/docker-archive-keyring.gpg

• Add the Docker repository and install:

echo "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list >/dev/null
sudo apt-get update
sudo apt-get install -y docker-ce docker-ce-cli containerd.io

• Post-install: enable and start Docker, add a user to the docker group:

sudo systemctl enable --now docker
sudo usermod -aG docker $USER

Log out and back in for group change to take effect. Verify with docker run --rm hello-world.

CentOS / RHEL (yum/dnf)

For CentOS 7/8 and RHEL, use the Docker repo or the CentOS Extras (older). Use yum or dnf depending on version.

• Install prerequisites and repository:

sudo yum install -y yum-utils device-mapper-persistent-data lvm2
sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo

• Install Docker Engine:

sudo yum install -y docker-ce docker-ce-cli containerd.io
sudo systemctl enable --now docker

• Test with docker run --rm hello-world. If using RHEL, subscribe to repositories or use the CentOS stream packages as appropriate.

Rootless Docker (optional for security)

Rootless mode lets non-root users run the Docker daemon with user namespaces, reducing blast radius. Install steps and prerequisites are documented by Docker; commonly you bootstrap with dockerd-rootless-setuptool.sh and enable the systemd user service. Rootless mode has differences in networking (VPNKit or slirp4netns) and storage paths, so test carefully before production.

Essential configuration for production VPS deployments

After installation, tune Docker for reliability and security. Key areas to configure include storage, logging, daemon options, and resource limits.

Configure daemon.json

Create or edit /etc/docker/daemon.json to declare storage driver, log rotation and registry mirrors. Example:

{
"storage-driver": "overlay2",
"log-driver": "json-file",
"log-opts": {
"max-size": "10m",
"max-file": "3"
},
"bip": "172.18.0.1/16"
}

Then reload systemd and restart Docker:

sudo systemctl daemon-reload
sudo systemctl restart docker

Storage and data directory

The default Docker root is /var/lib/docker. For heavy workloads, bind this mount to a dedicated SSD partition or LVM volume. To move it, stop Docker, update /etc/docker/daemon.json with "data-root": "/mnt/docker-data", relocate files and restart.

Logging and log rotation

Unbounded container logs can fill disk. Use the JSON-file driver with size limits (shown above) or send logs to a centralized system (syslog, fluentd, ELK). Monitor disk usage with docker system df and prune periodically with automated jobs (docker system prune).

Networking and firewalls

By default, Docker manages iptables rules and creates a bridge network. When using VPS firewall tools (ufw, firewalld), ensure Docker’s rules are not inadvertently blocked. Recommended steps:

• Allow necessary ports on VPS firewall (e.g., 80, 443, 22).
• When using Docker Swarm or Kubernetes, open the swarm/k8s control ports and the overlay network ports between nodes.
• Consider using macvlan for direct L2 IP assignment when you need container IPs on the same subnet as the host.

Security hardening

• Run containers with the least privilege: use non-root containers or map specific capabilities only.
• Use user namespaces or rootless Docker to contain root-level processes.
• Enable AppArmor or SELinux policies where available.
• Limit resources with cgroups via --memory, --cpus and set restart policies: --restart unless-stopped.
• Scan images for vulnerabilities using tools like dockle, Clair or Trivy before deployment.

Typical application scenarios and tooling

Docker fits many use cases on VPS hosts. Common patterns include:

• Single-app deployments: Run individual web services or API backends in containers, served via Nginx or Caddy as a reverse proxy.
• Multi-container stacks: Use Docker Compose for web + db + cache stacks. Compose files are easy to version-control and replicate.
• CI/CD pipelines: Build images in CI, push to a registry (Docker Hub, GitHub Packages, private registry), and pull to VPS for deployment.
• Microservices and orchestration: For multi-node clusters on VPS instances, Docker Swarm or Kubernetes (k3s) offer orchestration. Kubernetes requires more memory and networking setup; for small teams, Swarm or Nomad may be simpler.

Advantages and trade-offs versus alternatives

Below is a quick comparison to help choose the right approach:

• Docker containers vs VMs: Containers are more lightweight and faster to start. VMs provide stronger isolation via separate kernels—prefer VMs if you need full OS separation or run different kernels.
• Docker vs Podman: Podman is daemonless and can be run rootless by design. Docker has a rich ecosystem (Compose, Swarm) and broad tooling support. Podman is gaining parity, especially for rootless workflows.
• Docker vs containerd/runc: containerd is the runtime component used by Docker. For minimal setups, some teams run containerd directly or use higher-level orchestration that manages containerd for them.

Selecting the right VPS for Docker

Choosing appropriate VPS resources dramatically affects reliability and scalability. Consider these recommendations:

• CPU: Multi-core CPUs are important for parallel containers. For web workloads, at least 2 vCPUs are recommended for production.
• Memory: Containers can be memory-efficient, but databases and JVM-based services need generous RAM. Start with 4GB for small production stacks, 8–16GB for moderate loads.
• Storage: Prioritize NVMe/SSD storage with good IOPS. Separate OS and Docker data partitions if possible.
• Network: Ensure predictable bandwidth and low latency. If you expect high ingress/egress, choose a VPS plan with generous network allowances.
• Snapshots and backups: Use VPS snapshot features for quick rollback, and schedule persistent backups for volumes and critical data.

Operational tips and best practices

• Automate image builds and deployments using CI/CD pipelines to remove manual steps and ensure consistency.
• Tag images with semantic and immutable tags (e.g., app:1.2.3) and use registry immutability policies if available.
• Monitor containers and hosts using Prometheus, cAdvisor, Grafana and alerting to detect resource bottlenecks early.
• Use healthchecks in Dockerfiles and Compose files so orchestrators can auto-restart unhealthy containers.
• Regularly update Docker and container runtime to take advantage of security fixes and performance improvements.

Summary

Installing Docker on a VPS unlocks rapid, consistent deployments and a mature ecosystem of tools that accelerate development and operations. Ensure your VPS kernel and cgroup settings are compatible, use Docker’s official packages for updates, and configure storage, logging and security carefully. For production, pick a VPS plan with adequate CPU, RAM and SSD storage and integrate Docker usage with CI/CD, monitoring and backups.

If you’re looking for a reliable host to run your Dockerized workloads, consider checking VPS.DO’s USA VPS options for SSD-backed instances and consistent network performance: USA VPS. Properly sized VPS instances make a big difference when deploying containers at scale.