Bits of .NET

📦 Docker Swarm = Container Orchestration

Running containers at scale needs orchestration. Docker Swarm provides native clustering and orchestration.

📝 Swarm Setup

# Initialize Swarm
docker swarm init --advertise-addr 192.168.1.100

# Add Worker Nodes
docker swarm join --token SWMTKN-1-... 192.168.1.100:2377

# List Nodes
docker node ls

# Create Service
docker service create --name web --replicas 3 -p 80:80 nginx

# Scale Service
docker service scale web=5

# Update Service
docker service update --image nginx:latest web

# Remove Service
docker service rm web

# Service Status
docker service ls
docker service ps web
docker service logs web

🎯 Advanced Swarm Features

# Stack Deployment
version: '3.8'
services:
    web:
        image: nginx
        deploy:
            replicas: 3
            update_config:
                parallelism: 2
                delay: 10s
            restart_policy:
                condition: on-failure
        networks:
            - webnet

    database:
        image: postgres:15
        deploy:
            replicas: 1
        networks:
            - webnet

networks:
    webnet:

# Deploy Stack
docker stack deploy -c docker-compose.yml myapp

# Stack Commands
docker stack ls
docker stack ps myapp
docker stack services myapp
docker stack rm myapp

# Secrets Management
echo "password" | docker secret create db_password -
docker service create --secret db_password nginx

# Configs
docker config create app_config app.conf
docker service create --config app_config nginx

💡 Swarm Best Practices

• Use stacks for complex applications
• Implement rolling updates
• Use secrets for sensitive data
• Monitor service health
• Regularly update services