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 · 2017-09-10T13:43:23.933

25

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 '17 at 13:43

answered Sep 10 '17 at 13:30

yamenk

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5

I meant values in docker env file, not docker-compose file environment section – JavaSa Sep 10 '17 at 13:35
1

@JavaSa updated answer. The result is the same for both env_file and environment. – yamenk Sep 10 '17 at 13:38
Ok, does this apply also to docker-compose2? – JavaSa Sep 10 '17 at 13:40
@JavaSa yes same result with compose version: "2" – yamenk Sep 10 '17 at 13:44
1

What if I'm not using an env.conf? Do quotes still work in the yml file itself? – void.pointer Oct 10 '18 at 23:50
2

based on my experience @void.pointer, it doesn't work in the docker-compose.yml – Boris Feb 26 '20 at 15:13
Is there a solution for Docker run -e ? (without using an env file) – Alexis.Rolland Jan 22 '22 at 10:54

rickdenhaan · Answer 2 · 2017-09-10T13:40:47.367

20

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 '17 at 13:40

answered Sep 10 '17 at 13:22

rickdenhaan

10,857
28
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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 `dockerfile`s. – BrainSlugs83 Jul 28 '19 at 23:15

score 5 · Answer 3 · answered Feb 28 '18 at 11:34

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

score 0 · Answer 4 · answered Feb 18 '21 at 11:52

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

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

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