docker-compose-yml

• Compose YAML format has it's own versions:

Compose file format	Docker Engine release
3.8	19.03.0+
3.7	18.06.0+
3.6	18.02.0+
3.5	17.12.0+
3.4	17.09.0+
3.3	17.06.0+
3.2	17.04.0+
3.1	1.13.1+
3.0	1.13.0+
2.3	17.06.0+
2.2	1.13.0+
2.1	1.12.0+
2.0	1.10.0+
1.0	1.9.1.+

• YAML file can be used with docker-compose command for local docker automation or..

• With docker directly in production with Swarm (as of v1.13)

• docker-compose --help

• docker-compose.yml is default filename, but any can be used with docker-compose -f

More details https://docs.docker.com/compose/compose-file/compose-versioning/

Template

version: '3.1'  # if no version is specificed then v1 is assumed. Recommend v2 minimum

services:  # containers. same as docker run
  servicename: # a friendly name. this is also DNS name inside network
    image: # Optional if you use build:
    command: # Optional, replace the default CMD specified by the image
    environment: # Optional, same as -e in docker run
    volumes: # Optional, same as -v in docker run
  servicename2:

volumes: # Optional, same as docker volume create

networks: # Optional, same as docker network create

Using Compose to Build

• Compose can also build your custom images

• Will build them with docker-compose up if not found in cache

• Also rebuild with docker-compose build

• Great for complex builds that have lots of vars or build args

• Compose file build options