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

CaptainDumbass · December 8, 2025, 10:15pm

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

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

Important: 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:

Create admin account

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

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:

Go to Containers → Add container
Name: nginx-test
Image: nginx:latest
Port mapping:

Host: 8080
Container: 80

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

Go to Stacks → Add stack
Name: test-stack
Web editor: Paste this example:


version: '3.8'

services:

web:

image: nginx:latest

ports:

- "8080:80"

restart: unless-stopped

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

Your Turn

What’s the first service you’re planning to run in Docker?

Have you used Docker before, or is this your first time?

Any questions about containers or Portainer?

Drop a comment below!

Navigation: ← Part 3 | Part 5 →