how to cross docker-compose.yml file to link container

Question

docker-composeA.yml

mysql:
    image: mysql
    environment:
        - XXX=XXX
gogs:
    image: gogs/gogs
    links:
        - mysql:mysql # ok

docker-composeB.yml

tomcat:
    image: javaweb:8
    links:
        - mysql:mysql // wrong, can not find mysql defination

Now I want to link mysql container which defined in docker-composeA.yml, but when I run docker-compose up with docker-composeB.yml, it said 'mysql is undefined'. So How could I link container cross docker-compose.yml files.

Answer 1

links and depends_on both require a reference to a service defined in the same Docker Compose file. You need external_links .