How to Create Docker Containers from Scratch

Introduction

This tutorial provides a comprehensive guide on working with Docker Compose, focusing on addressing the "docker: 'compose' is not a docker command" error. You'll learn how to install and configure Docker Compose, build and manage your multi-container applications, and explore best practices for effective Docker Compose usage.

Docker Fundamentals

Introduction to Docker Containerization

Docker is a powerful container technology that revolutionizes application deployment and development. Container technology enables developers to package applications with all their dependencies, ensuring consistent performance across different computing environments.

Core Concepts of Docker

What is Docker?

Docker is an open-source platform for containerization that allows developers to automate application deployment, scaling, and management. It provides a lightweight alternative to traditional virtual machines by creating isolated environments called containers.

Key Docker Components

Docker Architecture

Basic Docker Commands and Examples

Installing Docker on Ubuntu 22.04

## Update system packages
sudo apt update

## Install Docker dependencies
sudo apt install apt-transport-https ca-certificates curl software-properties-common

## Add Docker's official GPG key
curl -fsSL  | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg

## Set up Docker repository
echo "deb [arch=amd64 signed-by=/usr/share/keyrings/docker-archive-keyring.gpg]  $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

## Install Docker Engine
sudo apt update
sudo apt install docker-ce docker-ce-cli containerd.io

Basic Docker Operations

## Pull an image from Docker Hub
docker pull ubuntu:latest

## List available images
docker images

## Run a container
docker run -it ubuntu:latest /bin/bash

## List running containers
docker ps

## Stop a container
docker stop <container_id>

Container Technology Benefits

Docker containerization offers several advantages:

• Consistent application environments
• Faster deployment and scaling
• Reduced resource consumption
• Improved development workflow
• Platform independence

Use Cases for Docker Containers

Docker is widely used in:

• Microservices architecture
• Continuous Integration/Continuous Deployment (CI/CD)
• Cloud-native application development
• Development and testing environments

Docker Compose Workflow

Understanding Docker Compose

Docker Compose is a tool for defining and running multi-container Docker applications. It allows developers to use a YAML file to configure application services, networks, and volumes, simplifying the process of managing complex containerized environments.

Docker Compose Architecture

Docker Compose Configuration

YAML File Structure

Practical Example: Web Application Deployment

Sample docker-compose.yml

version: '3.8'
services:
  web:
    image: nginx:latest
    ports:
      - "80:80"
    volumes:
      - ./website:/usr/share/nginx/html
  database:
    image: postgres:13
    environment:
      POSTGRES_PASSWORD: secretpassword
    volumes:
      - postgres_data:/var/lib/postgresql/data

volumes:
  postgres_data:

Docker Compose Commands

## Install Docker Compose on Ubuntu 22.04
sudo apt update
sudo apt install docker-compose

## Validate compose file
docker-compose config

## Start multi-container application
docker-compose up -d

## View running containers
docker-compose ps

## Stop and remove containers
docker-compose down

Service Orchestration Techniques

Docker Compose enables advanced service orchestration:

• Defining inter-container dependencies
• Managing environment variables
• Configuring network connections
• Controlling container startup order

Scalability and Flexibility

Multi-container applications benefit from:

• Modular architecture
• Easy horizontal scaling
• Simplified configuration management
• Consistent development environments

Advanced Docker Techniques

Docker Network Configuration

Network Types

Custom Network Creation

## Create custom bridge network
docker network create --driver bridge custom_network

## List networks
docker network ls

## Inspect network details
docker network inspect custom_network

Container Resource Management

Resource Constraints

services:
  webapp:
    image: nginx
    deploy:
      resources:
        limits:
          cpus: '0.50'
          memory: 512M
        reservations:
          cpus: '0.25'
          memory: 256M

Docker Volume Management

## Create named volume
docker volume create app_data

## Mount volume to container
docker run -v app_data:/app/data nginx

## List volumes
docker volume ls

## Remove unused volumes
docker volume prune

Dockerfile Optimization

## Multi-stage build example
FROM golang:1.17 AS builder
WORKDIR /app
COPY . .
RUN go build -o myapp

FROM alpine:latest
COPY --from=builder /app/myapp /usr/local/bin
ENTRYPOINT ["myapp"]

Advanced Troubleshooting

## Container log inspection
docker logs <container_id>

## Real-time resource monitoring
docker stats

## Container process details
docker top <container_id>

Security Enhancements

Runtime Security Options

## Run container with read-only filesystem
docker run --read-only nginx

## Limit container capabilities
docker run --cap-drop ALL --cap-add NET_BIND_SERVICE nginx

Performance Monitoring

## System-wide docker information
docker system info

## Disk usage analysis
docker system df

## Remove unused resources
docker system prune -a

Summary

By the end of this tutorial, you will have a deep understanding of Docker Compose and how to troubleshoot the "docker: 'compose' is not a docker command" error. You'll be able to set up, manage, and scale your Docker Compose applications with confidence, following industry-standard best practices for optimal performance and maintainability.