There is an issue with docker's scale
command. See as follows:
First, start up an instance of app
:
docker-compose build --no-cache && docker-compose up -d
We get one named container docker-numbering-issue_app_1
Then, scale it up to 2 instances:
docker-compose up -d --scale app=2 --no-recreate
all is well, we get another named container docker-numbering-issue_app_2
But, if we remove docker-numbering-issue_app_1
and then rename docker-numbering-issue_app_2
to docker-numbering-issue_app_1
:
docker-compose rm -f app_1 && docker rename docker-numbering-issue_app_2 docker-numbering-issue_app_1
and we try to scale again:
docker-compose up -d --scale app=2 --no-recreate
we'll see the new container is named docker-numbering-issue_app_3
!!! Unexpected name generation, IMO. This could be expected behavior but I missed or couldn't find in the docs where this is explained.