I have the following compose file:
services:
myproject:
environment:
- ASPNETCORE_ENVIRONMENT=Development
- ASPNETCORE_URLS=https://+:443;http://+:80
- ASPNETCORE_HTTPS_PORT=44308
- PROJECT_NAME=MyProject
volumes:
- ${APPDATA}/ASP.NET/Https:/root/.aspnet/https:ro
- ${APPDATA}/Microsoft/UserSecrets:/root/.microsoft/usersecrets:ro
- ${APPDATA}/Turma/${PROJECT_NAME}/Logs:/var/logs/${PROJECT_NAME}
On the line:
- ${APPDATA}/Turma/${PROJECT_NAME}/Logs:/var/logs/${PROJECT_NAME}
It recognises ${APPDATA} but for ${PROJECT_NAME} it uses the literal string not the environment variable value.
Is there a way to make this work so the actual project name is used in path?
As far as I am aware, you cannot reference your env variables defined within the compose file later in the same compose file and have them interpreted. Your definition of $APPDATA works since that's set in the host's environment, not the compose file.
I tested both using the env variable and a .env file with compose 2.3 and 3, and neither worked.
I recommend wrapping your compose file in a run script where you can set the variables needed in your host shell, so you can have those interpreted properly. If you're deploying with a standard tool such as ansible, jenkins, etc. those can all set variables for you. This can look like the following:
#!/bin/bash
export PROJECT_NAME=foo
docker-compose up -d
unset PROJECT_NAME
Although it may not work for creating volumes, if you just need the variable to do something during the container's runtime (such as setting another environment variable), that can be put into an entrypoint script as well.
Related
I need some help with the following template:
services:
nginx:
image: nginx
restart: unless-stopped
labels:
- "traefik.enable=true"
- "traefik.http.routers.nginx-${COMPOSE_PROJECT_NAME}.rule=Host(`fuu.bar`)"
networks:
- treafik
My goal is to create a template which I can use e. g. in portainer with almost zero configuration.
I thought that the following variables are available in docker-compose config but the expression ${COMPOSE_PROJECT_NAME} results in an empty string: docker-compose config
services:
nginx:
image: nginx
restart: unless-stopped
labels:
- "traefik.enable=true"
- "traefik.http.routers.nginx-.rule=Host(`fuu.bar`)"
networks:
- treafik
Are there any default environment variables provided by docker-compose which I can use for environment interpolation?
---- Update
I use traefik (v2) as a reverse proxy. To make the containers available through treafik, you need to define routers on every service. The router name has to be unique. Lets imagine you deploy 2 or more stacks of the above template. The router name has to be unique for all services across all stacks. Because Im a lazy guy, I tried to simply integrate the environment variable COMPOSE_PROJECT_NAME (which I know is already unique in my setup because every stack must have a unique name). But the variable is not available when deploying the stack.
Of course, I could simply define the variable COMPOSE_PROJECT_NAME by myself in a .env-file, but i hoped that there are any default environment variables provided by docker.
You can use environment variables to passing strings to your docker file.
There are many ways through docker documentation. For example:
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:
Starting with +v1.28, .env file is placed at the base of the project
directory
Project directory can be explicitly defined with the --file option or
COMPOSE_FILE environment variable. Otherwise, it is the current
working directory where the docker compose command is executed
(+1.28).
For previous versions, it might have trouble resolving .env file with
--file or COMPOSE_FILE. To work around it, it is recommended to use --project-directory, which overrides the path for the .env file. This inconsistency is addressed in +v1.28 by limiting the filepath to the
project directory.
I have an environment file that contain a variable called Database_User.
In my docker-compose, I have this:
services:
database:
container_name: postgres
hostname: db
image: postgres:12-alpine
environment:
- POSTGRES_USER=${Database_User}
ports:
- "54321:5432"
env_file: project/myproject/.env
But, I am getting an error:
The Database_User variable is not set. Defaulting to a blank string.
To get this right it is important to correctly understand the differences between the environment and env_file properties and the .env file:
environment and env_file let you specify environment variables to be set in the container:
with environment you can specify the variables explicitly in the docker-compose.yml
with env_file you implicitly import all variables from that file
mixing both on the same service is bad practice since it will easily lead to unexpected behavior
the .env file is loaded by docker-compose into the environment of docker-compose itself where it can be used
to alter the behavior of docker-compose with respective CLI environment variables
for variable substitution in the docker-compose.yml
So your current configuration does not do what you probably think it does:
env_file: project/myproject/.env
Will load that .env file into the environment of the container and not of docker-compose. Therefor Database_User won't be set for variable substitution:
environment:
- POSTGRES_USER=${Database_User}
The solution here: remove env_file from your docker-compose.yml and place .env in the same directory you are starting docker-compose from. Alternatively you can specify an .env file by path with the --env-file flag:
docker-compose --env-file project/myproject/.env up
EDIT:
This answer clearly explains the important difference from defining environment variables in an env file vs using variable substitution in a docker-compose file. I have edited my answer for clarity but please make sure you also understand the other answer.
Option 1
You likely have not set the environment variable Database_User for variable substitution to work and need to source wherever you have that defined before running docker-compose.
source ./database_user_defined_here.env
docker-compose up
You can review the docs on environment variable substitution: https://docs.docker.com/compose/environment-variables/#substitute-environment-variables-in-compose-files
Option 2
If you're using an environment file, you shouldn't have to specify the environment section (then just define POSTGRES_USER=... in that file). Then you'd run:
docker-compose --env-file ./your-env-file.env up
Or you can also specify the env file in docker-compose.yml:
database:
...
env_file:
- your-env-file.env
However, you must specify the environment variables explicitly in this file. These docs go over env file syntax.
I'm trying to get the Env-Variables in Docker-Compose to work. My Files:
env/test.env:
XUSER=you
XHOME=/home/${XUSER}
docker-compose.yml:
version: '3'
services:
abc:
build: .
image: xyz:latest
container_name: xyz
env_file:
- env/test.env
user: "${XUSER}"
docker-compose up --build
docker-compose config
WARNING: The XUSER variable is not set. Defaulting to a blank string.
services:
kernel:
build:
context: xyz
container_name: xyz
environment:
XHOME: /home/you
XUSER: you
image: xyz:latest
user: ''
As you can see user: '' is an empty string, but the env_file works. I found some old Bug reports about this issue, I'm not sure I doing something wrong or not.
Although the other answers are both correct they do not highlight the underlying misunderstanding here enough:
With the env_file option you can specify a file with variables to be injected into the environment in the container.
Using variable substitution in the docker-compose.yml you can access variables in the environment of the docker-compose command, i.e. on the host.
You can set these using the usual mechanisms of your OS/shell, e.g. in bash:
export XUSER=you
docker-compose up
Additionally with docker-compose you can use a .env file in the current directory.
So in your concrete example you should just move env/test.env to .env to add the variables to the environment of docker-compose for variable substitution.
If you also want to add them to the environment in the container you can do it like this:
version: '3'
services:
abc:
build: .
image: xyz:latest
container_name: xyz
# add variables from the docker-compose environment to the container:
environment:
- XUSER=$XUSER
# or even shorter:
- XHOME
# use variable from the docker-compose environment in the config:
user: "${XUSER}"
It says WARNING: The XUSER variable is not set. Defaulting to a blank string. because ${XUSER} doesn't exist at the time this is executed:
user: "${XUSER}"
${XUSER} is not in your environment (you can verify this by running: env | grep XUSER, which should output nothing), and docker-compose didn't find any .env file at the same level or no .env file was passed at the time you ran docker-compose up --build or docker-compose config
Flexible solution:
Rename env/test.env for .env and place it a the root of the folder container your docker-compose file so that docker automatically parses it.
Or use:
docker-compose --env-file path/to/env/test.env up --build
docker-compose --env-file path/to/env/test.env config
Permanent solution:
Export them manually in your environment by running:
export XUSER=you && export XHOME=/home/${XUSER}
Or you use your env/test.env file as a source (note that you'll need to prefix with 'export'):
env/test.env:
export XUSER=you
export XHOME=/home/${XUSER}
And then your run . /path/to/env/test.env or source /path/to/env/test.env
What you need to do is create .env file at the same directory as your docker-compose.yml file, the content of .env is :
XUSER=user1
then run docker-compose config
reference : https://docs.docker.com/compose/environment-variables/
Since +1.28 .env file is placed in project root, not where docker-compose is executed. If you do that the variables will be automatically pulled through to be available to the container.
This works great in dev, especially with a a bind-mount volume to make .env available to compose in project root without also going into image build by including .env in .dockerignore
But in production I was not comfortable including it in my project root especially since I was pulling those project files down from github. The Compose file expects them to be in the production environment to replace for substitution SECRET_VAR=${SECRET_VAR}
So one hack solution was to stick the .env file high in my production directory tree, far away from my project (ideally these would come from an environment store on the hosting service, or another encrypted store), but inject those variables into the container at runtime by using the --env_file flag in Compose up.
The env_file flag works Like this:
docker-compose -f docker-compose.prod.yml --env-file ../.env up -d
Its in the docs
I also started encountering this after upgrading to Docker Desktop 4.12.0. This error started happening for quoted strings inside of .env (when using env_file to load variables in docker-compose.yml). In that case, be sure to use single quotes instead of double quotes, i.e.
MY_VAR='foo$bar'
# ... instead of...
MY_VAR="foo$bar"
Try this, I hope it will work.
You need to escape the variable if you want it to be expanded inside the container, using a double-dollar sign ($${envVariable}).
If however, you want it to be interpreted on your host, the $envVariable needs to be defined in your environment or in the .env file. The env_file option defines environment variables that will be available inside the container only.
Within my docker-compose.yml file I have a service with lines like the following
environment:
- ENV1=hello
- ENV2=world
command: -f ./tmp/config.toml
volumes:
- ./config/config_x.toml:/tmp/config.toml
I want to make it so that if ENV1 is defined (i.e. not an empty string), then mount the volume
- ./config/config_x.toml:/tmp/config.toml
otherwise, mount the volume
- ./config/config_y.toml:/tmp/config.toml
What would be the best way of doing this?
You can add an env variable which holds the name of the volume you want to mount. For ex:
environment:
- ENV1=myvolume
- ENV2=world
command: -f ./tmp/config.toml
volumes:
- ./${myvolume}/config_x.toml:/tmp/config.toml
Docker-compose doesn't have explicit conditional statement(if) concepts.
To achieve what you want, you have to define a single property key which the value is different according to your target environment.
Besides, the interpolation of variable in a docker-compose template is done broadly in two ways :
set the variables in the caller shell
use an .env file (while it doesn't work with docker stack deploy).
Using .env is not enough for your case because you need to have a file by environment with the expected value for the same property key.
A possible approach would be probably to set variables in the shell.
Either manually : SRC_VOLUME=config_x.toml docker-compose up
and SRC_VOLUME=config_y.toml docker-compose up for the second.
Or by defining two files that contain the key=value that you have to write into your shell environment.
For example :
SRC_VOLUME=config_x.toml
and that in the second :
SRC_VOLUME=config_y.toml
In any case you just need to use a placeholder in the docker-compose template :
volumes:
- ./config/${SRC_VOLUME}:/tmp/config.toml
I'm trying to get a docker-compose file working with multiple .env files, and I'm not having any luck. I'm trying to setup three .env files:
global settings that are the same across all container instances
environment-specific settings (stuff just for test or dev)
local settings - overridable things that a developer might need to change in case they have conflicts with, say, a port number
My docker-compose.yml file looks like this:
version: '2'
services:
db:
env_file:
- ./.env
- ./.env.${ENV}
- ./.env.local
image: postgres
ports:
- ${POSTGRES_PORT}:5432
.env looks like this:
POSTGRES_USER=myapp
and the .env.development looks like this:
POSTGRES_PASSWORD=supersecretpassword
POSTGRES_HOST=localhost
POSTGRES_PORT=25432
POSTGRES_DB=myapp_development
.env.local doesn't exist in this case.
After running ENV=development docker-compose up, I receive the following output:
$ ENV=development docker-compose up
WARNING: The POSTGRES_PASSWORD variable is not set. Defaulting to a blank string.
WARNING: The POSTGRES_DB variable is not set. Defaulting to a blank string.
WARNING: The POSTGRES_PORT variable is not set. Defaulting to a blank string.
ERROR: The Compose file './docker-compose.yml' is invalid because:
services.db.ports is invalid: Invalid port ":5432", should be [[remote_ip:]remote_port[-remote_port]:]port[/protocol]
From that error message, it looks like none of my environment variables are being used. I just upgraded to the newest available docker-compose as well - same errors:
$ docker-compose --version
docker-compose version 1.8.0-rc1, build 9bf6bc6
Any ideas here? Would be nice to have a single docker-compose.yml that would work across multiple environments.
In order to apply different/multiple env_files depending on the running environment, such as development/staging/production, I think a better way for docker-compose is to use multiple docker-compose yml files.
For example:
1. Start with a base file that defines the canonical configuration for the services.
docker-compose.yml
web:
image: example/my_web_app:latest
env_file:
- .env
2. Add the override file for development, as its name implies, can contain configuration overrides for existing services or entirely new services.
docker-compose.override.yml
web:
build: .
volumes:
- '.:/code'
ports:
- 8883:80
env_file:
- .env.dev
When you run docker-compose up it reads the overrides automatically.
3. Create another override file for the production environment.
docker-compose.prod.yml
web:
ports:
- 80:80
env_file:
- .env.prod
To deploy with this production Compose file you can run
docker-compose -f docker-compose.yml -f docker-compose.prod.yml up
Note
My Docker version:
$ docker -v
Docker version 18.06.1-ce, build e68fc7a
$ docker-compose -v
docker-compose version 1.22.0, build f46880fe
Reference: https://docs.docker.com/compose/extends/
Keep in mind that there are 2 different environments where you are defining variables. The host machine where you are executing the docker-compose command, and the container itself (running the db service in your case).
Your docker-compose.yml file has access to your host's environment variables. Hence ENV is reachable from the docker-compose command, but not these in your .env files.
On the contrary, the value for ENV is not reachable inside the container, but all variables defined in your .env files will.
I don't know if you really need your db container to access the variables defined on your .env.development. But at least seem that your host machine needs to have the content of that file, so when the docker-compose command is called, the POSTGRES_PORT variable is defined.
To fix your specific problem you would need to define the environment variables on your host machine too, not only for the container. You could do something like this:
#Set for host
ENV=development
#Also sets the variables on the host
source ./.env.$ENV
#POSTGRES_PORT defined in .env.development is used here
docker-compose up
#since env_file also contains .env.development, the variables will be reachable from the container.
Hope that helps.
There is a misconception regarding the .env file and the env_file option in the docker-compose.yml, as it is very ambiguous. Shin points it out very nicely in the github issue docker-compose doesn't use env_file. I will just quote his summary:
Variable substitution in your docker-compose.yml file will be pulled (in decreasing order of priority) from your shell's environment and your .env file.
Variables available in your container are a combination of values found in your env_file files and values described in the environment section of the service.
Those are two entirely separate sets of features.
while reading this page: https://docs.docker.com/compose/environment-variables/
and from my understanding, you should do the following:
for the global variables(that should not change) make an env file like so:
VAR1=VALUE1
VAR2=VALUE2
and for the others(that might change) you should add their name under environment in docker-compose.yml like this:
environment:
- VAR1
- VAR2
this will take the VAR1 and VAR2 values from the shell you are running docker-compose.
I hope this helps.