Import docker compose file in another compose file

Question

Is it possible to "import" or link a docker-compose file into another docker-compose file?

Suppose I have two files:

# docker-compose-1.yml services:     A:         # config     B:         # config 

# docker-compose-2.yml services:     C:         # config     import: docker-compose-1.yml 

By running docker-compose -f docker-compose-2.yml up, I would like to start containers A, B (specified in the imported file) and C. Is this possible, without having to link both files with the -f parameter?

Answer 1

By extending

It's possible to extend or use multiple docker-compose files and their services and link them in just one file. You can take a look at this link to understand how is the other usages of multiple compose files. But you can't include the file yet without linking related files together as you mentioned.

Here, I defined a common-services.yaml:

version: '2'     services:     nginx_a:         image: nginx:latest         container_name: nginx         ports:          - 81:80          - 1443:443 

And then, I created a docker-compose.yml and included the common-services.yml file and its own service as well.

services:    nginx:      extends:          file: common-services.yml          service: nginx_a     nginx_b:       image: nginx:latest       container_name: nginx_b       volumes:       ports:        - 82:80        - 2443:443 

By .env technique

And if you want to avoid chaining usage of multiple files, there is also a technique with .env files. I will rewrite the previous example with .env technique.

COMPOSE_PATH_SEPARATOR=: COMPOSE_FILE=common-services.yml:docker-compose.yml 

Let's add another service as an example in the common-services.yml

 version: '2'  services:    ngin_a:      image: nginx:latest      container_name: nginx_a      ports:        - 81:80        - 1443:443     redis_c:      image: redis:latest      container_name: redis_c      ports:        - 6381:6380 

And finally, load all of them in the docker-compose file without even mention to those services.

version: '2'  services:    nginx_b:      image: nginx:latest      container_name: nginx_b      ports:        - 82:80        - 2443:443      env_file:        - .env 

In the end, you will have three running services.