Knowledge Base > IT & Systems > Docker & Portainer

Docker & Portainer - Container Management Made Easy [Part 4 of 10]

IT & Systems December 8, 2025

Installing Docker and setting up a beautiful web UI for managing containers

You've got your server running and storage configured. Now it's time to install the magic that makes everything easy: Docker.

Docker lets you run applications in isolated containers. No more dependency hell, no more "it works on my machine" problems. Each service runs in its own container with everything it needs.

And Portainer? That's your web-based control panel for managing all those containers without memorizing commands.

What is Docker?

Docker is a platform for running applications in containers.

Think of containers like:

  • Lightweight virtual machines (but way more efficient)
  • Self-contained packages with everything an app needs
  • Isolated environments that don't interfere with each other

Example:

  • Want to run a photo app? Pull a container.
  • Need a forum? Pull a container.
  • Want a wiki? Pull a container.

Each runs independently, uses minimal resources, and can be updated/removed without affecting others.

Why Docker for HomeLab?

Pros

  • Easy deployment - One command to install complex applications
  • Isolation - Apps don't conflict with each other
  • Portability - Move containers between servers easily
  • Updates - Pull new image, restart container, done
  • Rollback - Something breaks? Revert to old version instantly
  • Resource efficient - Much lighter than VMs
  • Huge ecosystem - Thousands of pre-built images available

Cons

  • Learning curve - New concepts to understand
  • Networking complexity - Can be confusing at first
  • Storage management - Need to understand volumes

Perfect For

  • Web applications
  • Databases
  • Media servers
  • Monitoring tools
  • Pretty much everything we're building in this series

What is Portainer?

Portainer is a web-based GUI for managing Docker.

Instead of typing commands like:

docker run -d --name myapp -p 8080:80 -v /data:/app/data myapp:latest

You click buttons in a web interface. Much easier for beginners (and faster for experts).

Features:

  • Visual container management
  • Template library for common apps
  • Stack deployment (docker-compose via web UI)
  • Resource monitoring
  • Log viewing
  • Network management
  • Volume management

And it's completely free (Community Edition).

Installing Docker

Step 1: Update System

# Update package lists and upgrade
sudo apt update && sudo apt upgrade -y

Step 2: Remove Old Docker Packages

If you have any old Docker installations, remove them:

# Remove conflicting packages
for pkg in docker.io docker-doc docker-compose docker-compose-v2 podman-docker containerd runc; do
  sudo apt-get remove $pkg
done

This ensures a clean installation.

Step 3: Install Docker's Official Repository

Add Docker's GPG key:

sudo apt-get update
sudo apt-get install ca-certificates curl -y
sudo install -m 0755 -d /etc/apt/keyrings
sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc
sudo 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" | \
  sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

Update package index:

sudo apt-get update

Step 4: Install Docker

Install Docker Engine and tools:

sudo apt-get install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin -y

This installs:

  • docker-ce - Docker Engine
  • docker-ce-cli - Docker command-line tools
  • containerd.io - Container runtime
  • docker-buildx-plugin - Build tool
  • docker-compose-plugin - Docker Compose (for multi-container apps)

Step 5: Verify Docker Installation

# Check Docker version
docker --version

# Test Docker with hello-world
sudo docker run hello-world

You should see a "Hello from Docker!" message. If so, Docker is working!

Step 6: Add Your User to Docker Group

This lets you run Docker without sudo:

# Add your user to docker group (replace 'admin' with your username)
sudo usermod -aG docker admin

# Log out and back in for changes to take effect
# Or run this to apply immediately:
newgrp docker

# Test without sudo
docker run hello-world
Note

Log out and back in (or reboot) for group changes to fully take effect.

Step 7: Enable Docker to Start on Boot

sudo systemctl enable docker.service
sudo systemctl enable containerd.service

Now Docker will start automatically when your server boots.

Step 8: Verify Docker Compose

Docker Compose is included as a plugin:

docker compose version

You should see something like Docker Compose version v2.x.x.

Installing Portainer

Now let's install Portainer to manage Docker via web UI.

Step 1: Create Portainer Data Directory

Create directory on your RAID array:

# Create directory for Portainer data
sudo mkdir -p /mnt/storage/docker/portainer_data

# Set ownership (replace 'admin' with your username)
sudo chown -R admin:admin /mnt/storage/docker

Step 2: Create Portainer Network

# Create a Docker network for Portainer
docker network create portainer-network

This network will be used by Portainer and other services.

Step 3: Deploy Portainer Container

Run Portainer:

docker run -d \
  --name portainer \
  --restart unless-stopped \
  -p 9443:9443 \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -v /mnt/storage/docker/portainer_data:/data \
  --network portainer-network \
  portainer/portainer-ce:latest

What this does:

  • -d - Run in background (detached)
  • --name portainer - Name the container
  • --restart unless-stopped - Auto-restart on boot
  • -p 9443:9443 - Expose web UI on port 9443
  • -v /var/run/docker.sock:/var/run/docker.sock - Access to Docker
  • -v /mnt/storage/docker/portainer_data:/data - Persistent data on RAID
  • --network portainer-network - Connect to network
  • portainer/portainer-ce:latest - Use latest Community Edition

Step 4: Configure Firewall for Portainer

On your Ubuntu server (via SSH), allow access to Portainer from your local network:

# Allow Portainer web UI from LAN
# NOTE: Replace 192.168.1.0/24 with YOUR network range
sudo ufw allow from 192.168.1.0/24 to any port 9443 proto tcp comment 'Portainer from LAN'

# Check firewall status
sudo ufw status numbered

Step 5: Access Portainer Web UI

Open your web browser and go to:

https://192.168.1.100:9443

Replace 192.168.1.100 with your server's IP address.

You'll see a security warning because Portainer uses a self-signed SSL certificate. This is normal. Click "Advanced" and proceed.

Step 6: Initial Portainer Setup

First-time setup:

1. Create admin account

  • Username: admin (or your choice)
  • Password: Choose a strong password (12+ characters)
  • Click "Create user"

2. Connect to Docker

  • Select "Get Started"
  • Portainer will auto-detect your local Docker environment
  • Click on "local" to manage your Docker host

You're in! You should see the Portainer dashboard.

Portainer Quick Tour

Dashboard

  • Shows containers, images, volumes, networks
  • Quick stats on resource usage

Containers

  • View all running/stopped containers
  • Start, stop, restart, remove containers
  • View logs
  • Access container console
  • Inspect container details

Images

  • View downloaded images
  • Pull new images from Docker Hub
  • Remove unused images

Stacks

  • Deploy multi-container applications
  • Use docker-compose files via web UI
  • Manage entire application stacks

Volumes

  • Manage persistent data storage
  • Create, remove, inspect volumes

Networks

  • Manage Docker networks
  • Create custom networks for container communication

Deploying Your First Container (Example)

Let's deploy a simple test container using Portainer:

Via Portainer Web UI:

  1. Go to Containers > Add container
  2. Name: nginx-test
  3. Image: nginx:latest
  4. Port mapping: Host: 8080 / Container: 80
  5. Click Deploy the container

Access it:

http://192.168.1.100:8080

You should see the nginx welcome page!

Remove it when done:

  • Go to Containers
  • Select nginx-test
  • Click Remove

Docker Compose with Portainer

Docker Compose lets you define multi-container applications in a YAML file.

Example: Create a stack in Portainer

  1. Go to Stacks > Add stack
  2. Name: test-stack
  3. Web editor: Paste this example:
version: '3.8'

services:
  web:
    image: nginx:latest
    ports:
      - "8080:80"
    restart: unless-stopped
  1. Click Deploy the stack

That's it! The container is running. Much easier than command-line.

Monitoring with Portainer

View container logs:

  • Go to Containers
  • Click on container name
  • Click Logs
  • See real-time output

View resource usage:

  • Go to Containers
  • Click on container name
  • Click Stats
  • See CPU, memory, network usage

Access container console:

  • Go to Containers
  • Click on container name
  • Click Console
  • Select /bin/bash or /bin/sh
  • Click Connect
  • You're inside the container!

Best Practices

Container Data Storage

  • Always use volumes for persistent data
  • Store volumes on RAID array (/mnt/storage/docker/)
  • Never store important data inside containers (it's lost when container is removed)

Updates

  • Regularly update container images
  • Test updates before deploying to production
  • Keep Portainer itself updated

Security

  • Use strong passwords for Portainer
  • Only allow Portainer access from LAN (not internet)
  • Regularly review running containers
  • Remove unused images and containers

Backups

  • Backup /mnt/storage/docker/ directory
  • Export Portainer stacks as YAML files
  • Document your container configurations

TL;DR

  • Docker runs applications in isolated containers
  • Portainer provides a web UI for managing Docker
  • Installation: Add Docker repo, install Docker, deploy Portainer container
  • Access: https://your-server-ip:9443
  • Benefits: Easy deployment, isolation, portability, updates
  • Next: We'll set up Nginx Proxy Manager for reverse proxy and SSL in Part 5
Part 3: Storage with RAID 5 Part 5: Nginx Proxy Manager
Back to IT & Systems