Declare env variable which value include space for docker/docker-compose

Question

I have an environment variable defined in a file passed in via --env-file like this:
TEST_VAR=The value

Does anybody know whether this is legal? should I place " around the value for this to be interpreted as needed in docker? Thanks

EDIT: Quotation marks will not be a good solution as it is will be part of the val see reference here.

yamenk · Accepted Answer · 2017-09-10 13:43:23Z

29

Lets see the result running the following compose file:

version: "3"

services:
    service:
        image: alpine
        command: env
        env_file: env.conf

env.conf:

TEST_VAR1=The value
TEST_VAR2="The value2"

docker-compose up Result:

service_1 | PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
service_1  | TEST_VAR2="The value2"
service_1  | TEST_VAR1=The value
service_1  | HOME=/root

Therefore, it is legal to have spaces in the env value.

edited Sep 10, 2017 at 13:43

answered Sep 10, 2017 at 13:30

yamenk

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7 Comments

JavaSa Over a year ago

I meant values in docker env file, not docker-compose file environment section

yamenk Over a year ago

@JavaSa updated answer. The result is the same for both env_file and environment.

JavaSa Over a year ago

Ok, does this apply also to docker-compose2?

void.pointer Over a year ago

What if I'm not using an env.conf? Do quotes still work in the yml file itself?

Boris Over a year ago

based on my experience @void.pointer, it doesn't work in the docker-compose.yml

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rickdenhaan · Accepted Answer · 2017-09-10 13:40:47Z

21

You can escape the space with a \:

TEST_VAR=The\ value

Edit: This is how I pass them when starting the container (i.e. docker run -e TEST_VAR=The\ value hello-world). If you're using docker-compose or an env file, see the answer by @yamenk.

edited Sep 10, 2017 at 13:40

answered Sep 10, 2017 at 13:22

rickdenhaan

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1 Comment

BrainSlugs83 Over a year ago

This worked for me; so, I'm not sure what the other commentators are talking about! -- and the other answers are complete nonsense, and not related to dockerfiles.

MortenB · Accepted Answer · 2018-02-28 11:34:58Z

4

In Dockerfile use doublequotes, do not use singlequotes because they do not expand variables inside, excerp from passing buildargs/envs to dockerfile and into a python script below:

ARG HOST="welfare-dev testapi"
ENV HOST "${HOST}"
ARG SITENAME="Institusjon"
ENV SITENAME "${SITENAME}"
RUN cd ${TESTDIR}/sensiotools/sensiotools && cd test && \
  ./testapi-events.py --activate --sitename="${SITENAME}" --host="${HOST}" --dbcheck --debug --wait=0.5 && \
  ./testapi-events.py --deactivate --sitename="${SITENAME}" --host="${HOST}" --dbcheck --debug

answered Feb 28, 2018 at 11:34

MortenB

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Comments

Gabriele · Accepted Answer · 2021-02-18 11:52:57Z

0

My case with docker-compose, if that can help. I couldn't make use of the suggestions in the other answers.

For a variable in volumes, I could use the .env file:

# .env
LOCAL_DIR=/local/path

while for a variable with spaces (for https://github.com/wolfcw/libfaketime in my case) I had to use command line: FAKETIME_ARG="@2021-02-11 13:23:02" docker-compose up.

The resulting docker-compose file (note the ${} just for LOCAL_DIR) :

# docker-compose.yml
services:
  myservice:
    build:
      context: ./path/to/dir/of/Dockerfile
      args:
        - FAKETIME_ARG
    volumes:
      - ${LOCAL_DIR}:/path/in/container

answered Feb 18, 2021 at 11:52

Gabriele

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