Compose: Error after upgrading to 17.06

[dummycode]

After upgrading to 17.06 I receive the following error when running docker-compose up

Recreating 3976a0934e55_3976a0934e55_3976a0934e55_api_web_1 ... error

ERROR: for 3976a0934e55_3976a0934e55_3976a0934e55_api_web_1  Cannot create container for service web: invalid IP address in add-host: "db"

ERROR: for web  Cannot create container for service web: invalid IP address in add-host: "db"
ERROR: Encountered errors while bringing up the project.

Rolling back to 17.03.1-ce fixes this error. Any idea what is causing this?

[shin-]

Please share your Compose file(s).

[dummycode]

web:
      build: .
      ports:
          - "8878:80"
      volumes:
          - .:/var/www/my-api
      links:
          - db
      extra_hosts:
          - "db:db"
      environment:
          - TERM=xterm
  db:
      image: mysql:5.6.22
      environment:
          - MYSQL_ROOT_PASSWORD=password
          - MYSQL_DATABASE=mydatabasename
          - MYSQL_USER=root
          - MYSQL_PASSWORD=password
      ports:
         - "3333:3306"

[shin-]

That is not a valid extra_hosts entry (it should be host:IP). The good news is you can omit it entirely, since links already does what you're trying to do.

[dummycode]

Ah, guess I was confused why this broke after upgrading? Glad to know it is just an error on my end though.

[shin-]

My guess would be that the new engine release has additional checks on the extra_hosts field.