We recently open a discussion on the mattermost-docker repository, about the Docker requirements for Mattermost.
As you know, Mattermost have some requirements about server OS and software, and also about client Web browser. But the Mattermost Docker project have no requirements about the Docker and (especially) docker-compose version we support.
The most important point to define our requirements here, is docker-compose version 3. It allow to use the “future” of docker-compose, Docker stacks. But it required Docker engine version
1.13.0+, which is a “recent” version (2017-01). Also, some people might use the Ubuntu packaged Docker binary instead of the official (called
docker.io). I don’t know how many people it affect, but this package is, AFAIK, on
1.12.x. So using docker-compose
3.0+ could break things for those people.
From here, we have 3 solutions :
- we support docker-compose
3.0+and we consider people should have an almost up-to-date Docker version
- we do not support docker-compose
3.0+so we could announce “only” Docker
- we announce Docker
1.12+as requirements but we propose both
According to me, maintaining 2 docker-compose files is dirty since, for now, the only difference is a unique line, specifying the version number to use. But I also understand that some people may use sensitive systems and prefer to wait few months before updating Docker, and
1.13.0 is “only” 7 months old.
We would appreciate some other opinions from community to see if it is a mistake to drop support for Docker
1.12.x and fewer