Compose: Not possibe to set environment variable to empty string

[bergtwvd]

Version:
docker-compose version 1.11.2, build dfed245

I want to set the environment variable VAR1 in the compose file to an empty string, rather than having it unset.

````
version: '2'

services:
srv1:
image: myimagename
environment:

• VAR1=
  ````

However, with this setting in the docker compose file the variable VAR1 turns out to be unset once I run the container.

• If I use - VAR1="" then the value of VAR1 inside the container is ""
• If I use - VAR1=${UNSET} then VAR1 inside the container is unset
• If I use - VAR1: ${UNSET} I get the error services.rec.environment contains {"VAR1": ""}, which is an invalid type, it should be a string

Thus: how to assign an empty string to a variable in docker-compose?

[bergtwvd]

Found the problem - error in the shell script - close.

[daudn]

@bergtwvd How do you set ENV as empty?

[ryan-faculty]

so how did you do it?

[ryan-faculty]

Update: here's a hack: ENV EMPTY_VAR ${1:+1}
from https://docs.docker.com/engine/reference/builder/#environment-replacement