version: '3' services: candidate: build: context: ./proxyd dockerfile: Dockerfile ports: - 3001:3000 environment: - SERVERNAME=candidate primary: build: context: ./proxyd dockerfile: Dockerfile ports: - 3002:3000 environment: - SERVERNAME=primary secondary: build: context: ./proxyd dockerfile: Dockerfile ports: - 3003:3000 environment: - SERVERNAME=secondary