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Docker Setup

This tutorial covers how to install and configure Docker on your GoMami VPS for containerized application deployment.

Prerequisites​

  • A deployed VPS instance (Ubuntu 24.04 LTS recommended)
  • SSH access to your server
  • At least 1 GB of memory

Install Docker​

Ubuntu / Debian​

# Update packages
apt update

# Install dependencies
apt install -y ca-certificates curl gnupg

# Add Docker's official GPG key
install -m 0755 -d /etc/apt/keyrings
curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc
chmod a+r /etc/apt/keyrings/docker.asc

# Add Docker repository
echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/ubuntu \
  $(. /etc/os-release && echo "$VERSION_CODENAME") stable" | \
  tee /etc/apt/sources.list.d/docker.list > /dev/null

# Install Docker
apt update
apt install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

# Verify installation
docker --version
docker compose version

CentOS / AlmaLinux​

# Install dependencies
dnf install -y yum-utils

# Add Docker repository
yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo

# Install Docker
dnf install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

# Start and enable on boot
systemctl start docker
systemctl enable docker

Verify Installation​

# Run test container
docker run hello-world

# View Docker info
docker info

Configure Docker Mirror (Optional)​

If pulling images from Docker Hub is slow, configure a mirror:

mkdir -p /etc/docker

cat > /etc/docker/daemon.json << 'EOF'
{
  "registry-mirrors": [
    "https://mirror.ccs.tencentyun.com"
  ],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "10m",
    "max-file": "3"
  }
}
EOF

# Restart Docker
systemctl daemon-reload
systemctl restart docker
tip

GoMami's Asia-Pacific nodes have low latency to international networks, so Docker Hub speeds are usually fine. Skip mirror configuration if pull speeds are acceptable.

Common Docker Commands​

# Pull image
docker pull nginx:latest

# Run container
docker run -d --name my-nginx -p 80:80 nginx

# List running containers
docker ps

# View container logs
docker logs my-nginx

# Enter container
docker exec -it my-nginx /bin/bash

# Stop container
docker stop my-nginx

# Remove container
docker rm my-nginx

# List images
docker images

Docker Compose Example​

Deploy multi-container apps with Docker Compose. Here's an Nginx + MySQL example:

# docker-compose.yml
services:
  web:
    image: nginx:latest
    ports:
      - "80:80"
    volumes:
      - ./html:/usr/share/nginx/html
    restart: unless-stopped

  db:
    image: mysql:8
    environment:
      MYSQL_ROOT_PASSWORD: your_secure_password
      MYSQL_DATABASE: myapp
    volumes:
      - mysql_data:/var/lib/mysql
    restart: unless-stopped

volumes:
  mysql_data:
# Start all services
docker compose up -d

# View service status
docker compose ps

# View logs
docker compose logs -f

# Stop all services
docker compose down

Resource Limits​

Set resource limits to prevent a single container from consuming too many resources:

# Limit memory and CPU
docker run -d \
  --name my-app \
  --memory="512m" \
  --cpus="1.0" \
  my-app-image
caution

VPS memory and CPU are limited. When running multiple containers, allocate resources carefully and leave enough for system overhead.

Next Steps​