Docker — Install & Manage | DevOps World

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Config files for Docker

Where to create or edit the main configuration — paths below match the setup steps.

Dockerfile
Location: Project root (or build context directory)
Image build instructions — FROM, COPY, RUN, CMD
/etc/docker/daemon.json
Location: Docker host (Linux)
Registry mirrors, storage driver, log options

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Related configs & repos

Copy-paste templates and production examples for Docker.

Config templates (16)

+ 10 more below

GitHub examples

🐙 docker-password-authentication↗Private registry auth with Docker

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Step 01

Install Docker

(01)Install Docker Engine

Install the Docker container runtime on your system.

Linux

1# Ubuntu / Debian
2sudo apt-get update
3sudo apt-get install -y ca-certificates curl gnupg
4sudo install -m 0755 -d /etc/apt/keyrings
5curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg
6echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu $(. /etc/os-release && echo "$VERSION_CODENAME") stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
7sudo apt-get update
8sudo apt-get install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
9 
10# RHEL / CentOS / Fedora
11sudo dnf -y install dnf-plugins-core
12sudo dnf config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
13sudo dnf install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

(02)Start Docker Service

Linux

1sudo systemctl enable docker
2sudo systemctl start docker
3sudo usermod -aG docker $USER
4# Log out and back in for group changes to take effect

✅

Step 02

Verify Installation

(01)Check Docker Version

Linux

1docker --version
2docker compose version

(02)Run Hello World Container

Linux

1docker run hello-world

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Step 03

Manage Docker

(01)Container Operations

Linux

1# List running containers
2docker ps
3 
4# List all containers
5docker ps -a
6 
7# Start / Stop / Remove
8docker start <container>
9docker stop <container>
10docker rm <container>

(02)Image Operations

Linux

1# List images
2docker images
3 
4# Pull / Build / Remove
5docker pull nginx:latest
6docker build -t myapp:1.0 .
7docker rmi <image>

(03)Docker Compose

Linux

1# Start services
2docker compose up -d
3 
4# View logs
5docker compose logs -f
6 
7# Stop and remove
8docker compose down

(04)System Cleanup

Linux

1# Remove unused containers, networks, images
2docker system prune -a
3 
4# Remove unused volumes (careful!)
5docker volume prune

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Step 04

Common Problems

#1Cannot connect to the Docker daemon

Linux

1# Add user to docker group
2sudo usermod -aG docker $USER
3# Log out and back in, then:
4sudo systemctl start docker
5docker ps

#2Port already in use

Linux

1# Find what's using the port
2sudo lsof -i :8080
3# Or use a different host port
4docker run -p 8081:80 nginx

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Step 05

Uninstall Docker

(01)Remove Docker

Linux

1# Ubuntu / Debian
2sudo apt-get purge -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
3sudo rm -rf /var/lib/docker /var/lib/containerd

📋Config templates

16 YAML templates for Docker. Copy and deploy after setup.

16 ready-to-copy templates. Expand one, copy the YAML, then run the deploy commands.

docker-compose.yaml

PostgreSQL database + Flask app with env file and volume persistence

yaml

1version: "3.9"
2 
3services:
4  db:
5    image: postgres:15-alpine
6    environment:
7      POSTGRES_DB: dukaan_db
8      POSTGRES_USER: dukaan
9      POSTGRES_PASSWORD: dukaan123
10    ports:
11      - "5432:5432"
12    volumes:
13      - pgdata:/var/lib/postgresql/data
14 
15  app:
16    build: .
17    ports:
18      - "5000:5000"
19    env_file:
20      - .env
21    depends_on:
22      - db
23 
24volumes:
25  pgdata:

Dockerfile

Flask application container image

dockerfile

1FROM python:3.12-slim
2WORKDIR /app
3COPY requirements.txt .
4RUN pip install --no-cache-dir -r requirements.txt
5COPY . .
6EXPOSE 5000
7CMD ["python", "app.py"]

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Step 01

Run with Docker Compose

(01)Build and start services

Linux

1cd your-project/
2docker compose up -d --build
3docker compose ps
4docker compose logs -f app

(02)Stop and clean up

Linux

1docker compose down
2docker compose down -v  # remove volumes