docker-compose scaling fix

[alexander-danilenko]

Description

There is --scale parameter in docker-compose (docs) that allows to start several instances of certain container. It's not working in current implementation.

Docker compose's --scale parameter is useful for running several container replicas in the same terminal window which is extremely handy for running on remote servers.

Current behavior:

After running the following command:

docker-compose up --build --scale uashield=5

I'm getting the following error:

Recreating uashield_uashield_1 ... done
Recreating uashield_uashield_2 ... error

ERROR: for uashield_uashield_2  Cannot create container for service uashield: b'Conflict. The container name "/uashield" is already in use by container "853da05e2937124032ca3398b9dcd8d2b40ec4be3d5947ac8c1e7d21b1ee2409". You have to remove (or rename) that container to be able to reuse that name.'

ERROR: for uashield  Cannot create container for service uashield: b'Conflict. The container name "/uashield" is already in use by container "853da05e2937124032ca3398b9dcd8d2b40ec4be3d5947ac8c1e7d21b1ee2409". You have to remove (or rename) that container to be able to reuse that name.'
ERROR: Encountered errors while bringing up the project.

Expected behavior

After running the following command:

docker-compose up --build --scale uashield=5

no errors need to be thrown. Containers need to be scaled to 5 running instances in parallel.

Proposed solution

Now scale parameter does not respected by docker-compose because of strictly defined container_name and image properties in uashield service. Just removing them will resolve the problem and container names for replicas will not conflict with any other replicas.

[Razikus]

Looks like good small change, thanks!