How to use environment variables in docker compose

Question

I would like to be able to use env variables inside docker-compose yml  with values passed in at the time of docker-compose up  This is the example  I am doing this today with basic docker run command  which is wrapped around my own script  Is there a way to achieve it with compose  without any such bash wrappers  proxy    hostname   hostname   volumes      -  mnt data logs  hostname  logs     -  mnt data  hostname  data

User · Answer

I have a simple bash script I created for this it just means running it on your file before use: https://github.com/antonosmond/subber

Basically just create your compose file using double curly braces to denote environment variables e.g:

app:
    build: "{{APP_PATH}}"
ports:
    - "{{APP_PORT_MAP}}"

Anything in double curly braces will be replaced with the environment variable of the same name so if I had the following environment variables set:

APP_PATH=~/my_app/build
APP_PORT_MAP=5000:5000

on running subber docker-compose.yml the resulting file would look like:

app:
    build: "~/my_app/build"
ports:
    - "5000:5000"

User · Answer

When using environment variables for volumes you need    create  env file in the same folder which contains docker-compose yaml  file declare variable in the  env file   HOSTNAME your hostname  Change  hostname to   HOSTNAME  at docker-compose yaml  file  proxy    hostname    HOSTNAME    volumes      -  mnt data logs   HOSTNAME   logs     -  mnt data   HOSTNAME   data    Of course you can do that dynamically on each build like   echo  HOSTNAME your hostname   gt   env  amp  amp  sudo docker-compose up

User · Answer

Since 1 25 4  docker-compose supports the option --env-file that enables you to specify a file containing variables   Yours should look like this   hostname my-host-name   And the command   docker-compose --env-file  path to my-env-file config

User · Answer

Use  env file to define dynamic values in docker-compse yml  Be it port or any other value   Sample docker-compose   testcore web         image  xxxxxxxxxxxxxxx dkr ecr ap-northeast-2 amazonaws com testcore latest        volumes               - c  logs c  logs        ports              -   TEST CORE PORT  80        environment              - CONSUL URL http     CONSUL IP  8500              - HOST   HOST ADDRESS    TEST CORE PORT    Inside  env file you can define the value of these variables   CONSUL IP 172 31 28 151 HOST ADDRESS 172 31 16 221 TEST CORE PORT 10002

User · Answer

The following is applicable for docker-compose 3 x Set environment variables inside the container         method - 1 Straight method   web    environment      - DEBUG 1       POSTGRES PASSWORD   postgres        POSTGRES USER   postgres       method - 2 The     env    file   Create a  env file in the same location as the docker-compose yml    cat  env TAG v1 5 POSTGRES PASSWORD   postgres    and your compose file will be like    cat docker-compose yml version   3  services    web      image   webapp   TAG       postgres password     POSTGRES PASSWORD     source

User · Answer

As far as I know  this is a work-in-progress  They want to do it  but it s not released yet  See 1377  the  new  495 that was mentioned by  Andy    I ended up implementing the  generate  yml as part of CI  approach as proposed by  Thomas

User · Answer

Create a template yml  which is your docker-compose yml with environment variable  Suppose your environment variables are in a file  env sh  Put the below piece of code in a sh file and run it       source env sh    rm -rf docker-compose yml    envsubst  lt   template yml     docker-compose yml     A new file docker-compose yml will be generated with the correct values of environment variables   Sample template yml file   oracledb          image    ORACLE DB IMAGE          privileged  true         cpuset   0          ports                  -    ORACLE DB PORT    ORACLE DB PORT           command   bin sh -c  chmod 777  tmp start   tmp start          container name    ORACLE DB CONTAINER NAME    Sample env sh file      bin bash  export ORACLE DB IMAGE  lt image-name gt   export ORACLE DB PORT  lt port to be exposed gt   export ORACLE DB CONTAINER NAME ORACLE DB SERVER

User · Answer

The best way is to specify environment variables outside the docker-compose yml file  You can use env file setting  and define your environment file within the same line  Then doing a docker-compose up again should recreate the containers with the new environment variables   Here is how my docker-compose yml looks like   services    web      env file  variables env      Note    docker-compose expects each line in an env file to be in VAR VAL format  Avoid using export inside the  env file  Also  the  env file should be placed in the folder where the docker-compose command is executed

User · Answer

env SOME VAR  I am some var  OTHER VAR  I am other var  docker stack deploy -c docker-compose yml   Use the version 3 6    version   3 6  services    one      image   nginx alpine      environment        foo   bar        SOME VAR        baz     OTHER VAR       labels        some-label    SOME VAR    two      image   nginx alpine      environment        hello   world        world     SOME VAR       labels        some-label    OTHER VAR    I got it form this link  https   github com docker cli issues 939

User · Answer

The DOCKER solution   It looks like docker-compose 1 5  has enabled variables substitution  https   github com docker compose releases  The latest Docker Compose allows you to access environment variables from your compose file  So you can source your environment variables  then run Compose like so   set -a source  my-env docker-compose up -d   Then you can reference the variables in docker-compose yml using   VARIABLE   like so   db    image   postgres   POSTGRES VERSION     And here is more info from the docs  taken here  https   docs docker com compose compose-file  variable-substitution     When you run docker-compose up with this configuration  Compose looks   for the POSTGRES VERSION environment variable in the shell and   substitutes its value in  For this example  Compose resolves the image   to postgres 9 3 before running the configuration       If an environment variable is not set  Compose substitutes with an   empty string  In the example above  if POSTGRES VERSION is not set    the value for the image option is postgres        Both  VARIABLE and   VARIABLE  syntax are supported  Extended   shell-style features  such as   VARIABLE-default  and     VARIABLE foo bar   are not supported       If you need to put a literal dollar sign in a configuration value  use   a double dollar sign         And I believe this feature was added in this pull request  https   github com docker compose pull 1765  The BASH solution   I notice folks have issues with Docker s environment variables support  Instead of dealing with environment variables in Docker  let s go back to basics  like bash  Here is a more flexible method using a bash script and a  env file   An example  env file   EXAMPLE URL http   example com   Note that the variable below is commented out and will not be used    EXAMPLE URL http   example2 com  SECRET KEY ABDFWEDFSADFWWEFSFSDFM    You can even define the compose file in an env variable like so  COMPOSE CONFIG my-compose-file yml   You can define other compose files  and just comment them out   when not needed    COMPOSE CONFIG another-compose-file yml   then run this bash script in the same directory  which should deploy everything properly      bin bash  docker rm -f  docker ps -aq -f name myproject    set -a source  env cat   COMPOSE CONFIG    envsubst   docker-compose -f - -p  myproject  up -d   Just reference your env variables in your compose file with the usual bash syntax  ie   SECRET KEY  to insert the SECRET KEY from the  env file    Note the COMPOSE CONFIG is defined in my  env file and used in my bash script  but you can easily just replace   COMPOSE CONFIG  with the my-compose-file yml in the bash script   Also note that I labeled this deployment by naming all of my containers with the  myproject  prefix  You can use any name you want  but it helps identify your containers so you can easily reference them later  Assuming that your containers are stateless  as they should be  this script will quickly remove and redeploy your containers according to your  env file params and your compose YAML file   Update Since this answer seems pretty popular  I wrote a blog post that describes my Docker deployment workflow in more depth  http   lukeswart net 2016 03 lets-deploy-part-1  This might be helpful when you add more complexity to a deployment configuration  like nginx configs  LetsEncrypt certs  and linked containers

User · Answer

add env to  env file Such as VERSION 1 0 0  then save it to deploy sh INPUTFILE docker-compose yml RESULT NAME docker-compose product yml NAME test  prepare             local inFile   pwd   INPUTFILE         local outFile   pwd   RESULT NAME         cp  inFile  outFile         while read -r line  do             OLD IFS  quot  IFS quot              IFS  quot   quot              pair   line              IFS  quot  OLD IFS quot                 sed -i -e  quot s      pair 0      pair 1   g quot   outFile             done  lt  env                deploy             docker stack deploy -c  outFile  NAME             prepare deploy

User · Answer

It seems that docker-compose has native support now for default environment variables in file   all you need to do is declare your variables in a file named  env and they will be available in docker-compose yml   For example  for  env file with contents   MY SECRET KEY SOME SECRET IMAGE NAME docker image   You could access your variable inside docker-compose yml or forward them into the container   my-service    image    IMAGE NAME    environment      MY SECRET KEY    MY SECRET KEY

User · Answer

You cannot     yet  But this is an alternative  think like a docker-composer yml generator   https   gist github com Vad1mo 9ab63f28239515d4dafd  Basically a shell script that will replace your variables  Also you can use Grunt task to build your docker compose file at the end of your CI process

[docker] How to use environment variables in docker compose

Examples related to docker

Examples related to docker-compose