docker-compose.yml

# This file is responsible for maintaining services in docker for load balancing of different number of containers
version: "3" #Using version 3 of docker compose for services
services:
  nodejs: # This is our service name
   #replace username/repo:tag with your name and image details
    
    image: sharmavivek62/backend:latest # our image path
    deploy: # Deploy Image 
      placement: # Service will run on swarm manager
        constraints: [node.role == manager]
      replicas: 2 # Use 2 instances of image for load balancing
      resources: # What resources does these instances uses
        limits: # Limit resources to instances
          cpus: "0.2" #20% of the cpu is used for one instance total 100% cpu usage for 5 instance
          memory: 50M #50M of memory is used for one instance
      restart_policy: #Restart instance on failure
        condition: on-failure
    ports: # node js Listen on port
      - "3000:8080"
    depends_on:
      - mongo
  mongo: # This is our other serivce name used for mongodb
    
    image: mongo #service image path
    deploy: # Deploy Image 
      replicas: 2 # Use 2 instances of image for load balancing
      resources: # What resources does these instances uses
        limits: # Limit resources to instances
          cpus: "0.2" #20% of the cpu is used for one instance total 100% cpu usage for 5 instance
          memory: 50M #50M of memory is used for one instance
      restart_policy: #Restart instance on failure
        condition: on-failure
      
    ports: # mongodb port
      - "27017:27017"
    volumes: # mongodb data volume storage
      - "./data:/data/db"