In the first line of the docker-compose.yml file we specify a version:
version: '3.9'
What exactly does this mean?!
After installing the latest version, I tried the following in my Windows 10 cmd:
docker-compose --version
and the output was:
Docker Compose version v2.17.2
so how is it that we type 3.9 in the first line?!
>Solution :
https://docs.docker.com/compose/compose-file/04-version-and-name/
Top-level version property is defined by the specification for backward compatibility but is only informative.
It specifies the version of the compose file schema, not the version of docker-compose.