127.0.0.1 localhost not working code example

Example: 127.0.0.1:8000 localhost not working

# can not acces django server ,add this and then try

version: "2"

services:
  postgres:
    image: postgres:9.6
    volumes:
      - pgdata:/var/lib/data/postgres

  backend:
    build: .
    command: gosu app bash
    volumes:
      - .:/app
      - pyenv:/python
    links:
      - postgres:postgres
    ports:
      - 8000:8000

volumes:
  pyenv:
  pgdata: