I have a .env file like this:
PROJECT_DIR=./test_dir
SUB_DIR=$(PROJECT_DIR)/sub_dir
And docker-compose.yml file like this:
version: '3.5'
services:
service_nginx:
image: nginx
volumes:
- ${SUB_DIR}:/var/www/html
But I can't use $SUB_DIR in docker-compose.yml file for volume, I got error like this:
ERROR: Named volume "$(PROJECT_DIR)/sub_dir:/var/www/html:rw" is used in service "service_nginx" but no declaration was found in the volumes section.
Update your env file as follows
export PROJECT_DIR=./test_dir
export SUB_DIR=$(PROJECT_DIR)/sub_dir
Then run the following command to read the varialbes;
. ./.env
Then deploy the stack from same terminal session.
Related
Is there a way to inject environment variables to all of my docker-compose services, without explicitly declaring them in each service's configuration?
1)using the env_file directive
you can use the env_file directive within your docker-compose.yml file
You can pass multiple environment variables from an external file
through to a service’s containers with the ‘env_file’ option, just
like with docker run --env-file=FILE ...:
you will have to declare the env file for each service that will use it and that is it.
example :
the docker-compose.yml file :
version: "3"
services:
database:
image: "ubuntu"
tty: true
env_file:
- same-variables.env
web:
image: "ubuntu"
tty: true
env_file:
- same-variables.env
the same-variables.env file
IS_DOCKER_COMPOSE=yes
then if you do opening a terminal :
docker exec -it <docker_container> "echo $IS_DOCKER_COMPOSE"
result will be :
yes
2)using the .env file in project root
According to the doc: https://docs.docker.com/compose/environment-variables/#the-env-file
You can set default values for any environment variables referenced in
the Compose file, or used to configure Compose, in an environment file
named .env. The .env file path is as follows
Create an .env file as the root of your project as follow.
example :
your .env file :
TAG=v1.5
your docker-compose.yml file :
version: '3'
services:
web:
image: "webapp:$TAG"
organization of your project should be :
root_folder
|-.env
|-docker-compose.yaml
with the .env file with all your variable
the env file will work for all of them at the same time
My docker-compose.yml
version: '3'
services:
test:
build: .
My Dockerfile
FROM alpine:latest
ENTRYPOINT echo $ARG1 $ARG2
My .env file
ARG1=argument100
ARG2=argument200
If I run docker-compose run test the empty line got printed. However, it I add env_file section to my docker-compose.yml I am getting the expected output.
New docker-compose.yml
version: '3'
services:
test:
build: .
env_file:
- .env
Running docker-compose again
$ docker-compose run test
argument100 argument200
Am I using an illegal way to pass arguments to the ENTRYPOINT command inside the Docker? Why is .env not loaded automatically upon docker-compose run?
The .env file is used to set variables in the docker-compose command itself that can be used to expand variables in the docker-compose.yml file itself. The env_file specification will define variables inside the containers. They operate at two different levels.
There's also a third type of variable, build args, that can be injected into the building of an image.
Each of these has a distinct purpose, and are not multiple ways to do the same thing.
I have a .env file with a large list of variables in the root of my node project. In the root is also my docker-compose.yml file:
version: '3'
services:
api:
build: .
env_file:
- .env
ports:
- 5000:5000
I'm trying to pass in these variables to Docker (from here), but when I run docker-compose up, I'm running into an error in my node app because it doesn't have access to these variables. What am I doing wrong? Thanks.
Change the file name to something different like node.env. The .env file is used by the docker-compose itself to define the content of the docker-compose file itself.
Example:
$ cat .env
TAG=v1.5
$ cat docker-compose.yml
version: '3'
services:
web:
image: "webapp:${TAG}"
The content of this file is not used inside the docker instance itself.
I have a cache folder and the path is stored in an evironment variable: $LOCAL_CACHE (export LOCAL_CACHE=/home/me/path/to/any/cache/folder)
Now I want to append some additional folders inside my .env file:
My .env file:
LOCAL_COMPOSER_DIR=${LOCAL_CACHE}/composer
LOCAL_NPM_DIR=${LOCAL_CACHE}/npm
LOCAL_BOWER_DIR=${LOCAL_CACHE}/bower
My docker_compose.yml looks like that:
version: '2'
services:
composer:
env_file: .env
image: composer/composer
volumes:
- ./src:${APP_ROOT}
- ${LOCAL_COMPOSER_DIR}:/composer
working_dir: ${APP_ROOT}
When I start the service with docker-compose run composer instal. ... it stops with following error: ERROR: Named volume "$LOCAL_CACHE"/composer":/composer:rw" is used in service "composer" but no declaration was found in the volumes section.
I'm not shure but it seems, the .env file doesn't support the use of variables.
Yes. Into .env file you can not use variables. Suddenly but true. Actual for docker compose version 1.8.
But you can use variables into docker-compose.yml file like
volumes:
- ${LOCAL_COMPOSER_DIR}/${CACHE_DIR}:/composer/${CACHE_DIR}
This answer suggest us another way.
i get crazy with the env_file setting inside my docker-compose.yml.
when i name the file .env and put it in the root of my project everything works fine. the main point of having this env file was to have multiple enviroments (dev, staging, production) where i made my settings.
as soon i name my file different (for example dev.env and put it inside a env folder) and try to load it inside my docker-compose file it won't work.
i make a simple example to make things clear.
for simplicity i use one variable DC_DOCKERFILE where i define what dockerfile to load.
file: .env in the root folder:
COMPOSE_PROJECT_NAME=test
DC_DOCKERFILE=./Dockerfile.bash.dev
file: docker-compose.yml:
version: "2"
services:
bash:
build:
context: .
dockerfile: ${DC_DOCKERFILE}
and docker-compose config shows everything is cool and build works as well:
networks: {}
services:
bash:
build:
context: /devops/myproject
dockerfile: ./Dockerfile.bash.dev
version: '2.0'
volumes: {}
now the point which freaks me out:
create a folder env in the root of the project
move .env to ./env/dev.env
add env_file: ./env/dev.env inside my docker-compose.yml
env content looks same like above so i don't post the content again.
my new docker-compose.yml:
version: "2"
services:
bash:
env_file: ./env/dev.env
build:
context: .
dockerfile: ${DC_DOCKERFILE}
only change, add the env_file settings.
and now i docker-compose config gives me this:
networks: {}
services:
bash:
build:
context: /devops/myproject
dockerfile: ''
environment:
COMPOSE_PROJECT_NAME: test
DC_DOCKERFILE: ./Dockerfile.bash.dev
version: '2.0'
volumes: {}
say what? where the hack is my dockerfile settings?
of course docker-compose build don't like that too and bothers with:
docker-compose build --force-rm --no-cache
WARNING: The DC_DOCKERFILE variable is not set. Defaulting to a blank string.
Building bash
ERROR: Cannot locate specified Dockerfile: Dockerfile
the variables get loaded but somehow not assigned.
so i don't get it.
am i maybe wrong and i can't use the env file for docker-compose stuff inside the docker-compose.yml file. would make sence that it need to be loaded first somehow via docker-compose parameter or something but after i spend so much time i want to know if i can load it inside or not :)
thanks for help and hell yeah for open source and the awesome community.
peace out
When .env file is present in the folder docker-compose command is executed, those environment variables are used as environment variables for docker-compose execution and variable substitution. (https://docs.docker.com/compose/env-file/).
However when you define env_file option to your service, the service will get those variables from the file as environment variables and those are not used for variable substitution.