Compose: Compatibility issue: Empty env variable for external network name no longer supported

[fmuelle1]

Description of the issue

I have a compose file in compose version 2.1 that uses an externally defined Docker network.

version: '2.1'
services:
  db:
    image: postgres:latest
  redis:
    image: redis:latest
    networks:
        default:
          aliases:
            - redis-${NETWORK}
networks:
  default:
    external:
      name: ${NETWORK}

The name of the network is handed into the compose run via environment variable NETWORK.
I used the following command to test the compose file:

docker-compose -p myComposeID pull

If that env variable is not set at all or if it is an empty string, the following happen:

• Up to Docker compose version 1.15 it works and shows the following output:

docker -v
Docker version 18.06.1-ce, build e68fc7a215d7133c34aa18e3b72b4a21fd0c6136

docker-compose -v
docker-compose version 1.15.0, build e12f3b9

docker-compose -p myComposeID up -d
The NETWORK variable is not set. Defaulting to a blank string.
Creating network "mycomposeid_default" with the default driver
Pulling redis (redis:latest)...
latest: Pulling from library/redis

Digest: sha256:b950de29d5d4e4ef9a9d2713aa1213f76486dd8f9c0a43e9e8aac72e2cfc3827
Status: Downloaded newer image for redis:latest
Pulling db (postgres:latest)...
latest: Pulling from library/postgres

Digest: sha256:4b8d2a83873b0721a09bed00ba7aa1a45569ac1d763ca6873460626a6e8bd1a5
Status: Downloaded newer image for postgres:latest

Creating mycomposeid_redis_1 ... 
Creating mycomposeid_db_1 ...

Creating mycomposeid_redis_1 ... done
Creating mycomposeid_db_1 ... done

docker network ls
NETWORK ID          NAME                  DRIVER              SCOPE
251c6f977eab        bridge                bridge              local
0e5fabcbdd20        host                  host                local
d77b71b487fe        mycomposeid_default   bridge              local
1e6af3c3a339        none                  null                local


docker-compose -p myComposeID down
The NETWORK variable is not set. Defaulting to a blank string.
Stopping mycomposeid_db_1    ... 
Stopping mycomposeid_redis_1 ... 

Stopping mycomposeid_redis_1 ... done
Stopping mycomposeid_db_1    ... done

Removing mycomposeid_db_1    ... 
Removing mycomposeid_redis_1 ... 

Removing mycomposeid_db_1    ... done
Removing mycomposeid_redis_1 ... done
Removing network mycomposeid_default

The compose command creates a default network and connects the 2 container to the network. I was able to verify that the network is there and used by the container.

• From Docker compose version 1.15 and higher the same compose file with the same command fails with a stack trace:

docker -v
Docker version 18.06.1-ce, build e68fc7a215d7133c34aa18e3b72b4a21fd0c6136

docker-compose -v
docker-compose version 1.23.1, build b02f1306

docker-compose -p myComposeID pull
The NETWORK variable is not set. Defaulting to a blank string.
[6969] Failed to execute script docker-compose
Traceback (most recent call last):
  File "bin/docker-compose", line 6, in <module>
  File "compose/cli/main.py", line 71, in main
  File "compose/cli/main.py", line 124, in perform_command
  File "compose/cli/command.py", line 42, in project_from_options
  File "compose/cli/command.py", line 128, in get_project
  File "compose/project.py", line 100, in from_config
  File "compose/network.py", line 320, in get_networks
  File "compose/network.py", line 125, in true_name
  File "compose/network.py", line 146, in _set_legacy_flag
  File "compose/network.py", line 106, in inspect
  File "site-packages/docker/utils/decorators.py", line 17, in wrapped
docker.errors.NullResource: Resource ID was not provided

Context information (for bug reports)

Output of docker-compose version

docker-compose version 1.15.0
docker-compose version 1.23.2

Output of docker version

Docker version 18.06.1-ce

Additional information

OS version / distribution:
Amazon ECS-optimized Amazon Linux AMI 2017.09.g
Amazon ECS container agent version 1.16.2

[simonferquel]

This is a breaking change.
@ulyssessouza or @rumpl PTAL

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale[bot]]

This issue has been automatically closed because it had not recent activity during the stale period.

[AminovE99]

This error is actual. I had the same

[mansiganatralat]

Facing the same issue. Any solution?

[marono]

Anyone came up with a solution to this? Seeing the same in one of our CI environments ...

EDIT: Going to reply my own issue just in case someone else comes across this - if you've got parameterized network names in your docker-compose file, generate a .env with that network name before pulling. It will sort things out.

[14MR]

Just faced the problem with docker-compose version 1.26.2, build eefe0d31