What is your experience with Docker?

Over 5 years of active experience using Docker in various projects.

The experience includes:

• Developing Dockerfiles: Creating optimized and multi-stage Dockerfiles for building application images (web, microservices, databases, etc.).
• Managing images: Working with Docker Hub, private repositories (GitLab Registry, Nexus), tagging, versioning, cleaning up unused images.
• Working with containers: Running, stopping, restarting, monitoring status, viewing logs, executing commands inside containers (docker exec).
• Docker Compose: Using it to define and run multi-container applications, orchestrate services, manage networks and volumes.
• Docker networks: Understanding and configuring various network drivers (bridge, host, overlay), creating custom networks for service isolation.
• Docker volumes: Using named volumes and bind mounts for data persistence, file sharing between host and container.
• Docker security: Understanding container isolation basics, using rootless Docker (where possible), scanning images for vulnerabilities.
• CI/CD integration: Incorporating Docker image build and publish steps into CI/CD pipelines (Jenkins, GitLab CI, GitHub Actions).
• Orchestration (basic knowledge): General understanding of Kubernetes principles (deploying containers, pods, replication, services), experience running simple applications in minikube/Kind for testing.

Examples of Docker Compose usage:

# docker-compose.yaml
version: '3.8'

services:
  app:
    build: .  # Build image from current directory
    ports:
      - "80:80" # Forward port 80 of host to port 80 of container
    environment:
      DATABASE_URL: postgres://user:password@db:5432/mydatabase # Environment variables
    depends_on:
      - db # Dependency on db service

  db:
    image: postgres:14 # Using the standard postgres image
    volumes:
      - db_data:/var/lib/postgresql/data # Persistent volume for data
    environment:
      POSTGRES_USER: user
      POSTGRES_PASSWORD: password
      POSTGRES_DB: mydatabase

volumes:
  db_data: # Named volume definition