Pass argument syntax in Docker Compose file.

docker-compose.yml

version: "3.5"
#$ docker run -d -p 6379:6379 redis
services:
  redis:
    image : redis
    ports:
      - "6379:6379"
  api_server:
    depends_on:
      - redis
    build:
      context: .
      dockerfile: api.Dockerfile
      args:
        PORT: 8080
    ports:
      - "8080:8080"


  selam_server:
      build:
        context: .
        dockerfile: selam.Dockerfile
        args:
          PORT: 15120
      ports:
        - "15120:15120"