docker-compose: Is it possible to share env variable within services? - docker-compose

I have docker compose file as follows.
docker-compose.yml
version: '2'
services:
web:
environment:
- var1 : 'localhost'
- var2 : 'root'
api:
environment:
- var1 : 'localhost'
- var2 : 'root'
How can I share these env variables without declaring for each service?
is it possible to share env variables within services?

We can able to share environment variables using 'extends' option.
version: '2'
services:
web:
environment:
- var1 : 'localhost'
- var2 : 'root'
api:
extends: web # serveice api, will have access to all configs of web

Related

Cannot connect to mongodb container from another compose [duplicate]

I have two separate docker-compose.yml files in two different folders:
~/front/docker-compose.yml
~/api/docker-compose.yml
How can I make sure that a container in front can send requests to a container in api?
I know that --default-gateway option can be set using docker run for an individual container, so that a specific IP address can be assigned to this container, but it seems that this option is not available when using docker-compose.
Currently I end up doing a docker inspect my_api_container_id and look at the gateway in the output. It works but the problem is that this IP is randomly attributed, so I can't rely on it.
Another form of this question might thus be:
Can I attribute a fixed IP address to a particular container using docker-compose?
But in the end what I'm looking after is:
How can two different docker-compose projects communicate with each other?
You just need to make sure that the containers you want to talk to each other are on the same network. Networks are a first-class docker construct, and not specific to compose.
# front/docker-compose.yml
version: '2'
services:
front:
...
networks:
- some-net
networks:
some-net:
driver: bridge
...
# api/docker-compose.yml
version: '2'
services:
api:
...
networks:
- front_some-net
networks:
front_some-net:
external: true
Note: Your app’s network is given a name based on the “project name”, which is based on the name of the directory it lives in, in this case a prefix front_ was added
They can then talk to each other using the service name. From front you can do ping api and vice versa.
UPDATE: As of compose file version 3.5:
This now works:
version: "3.5"
services:
proxy:
image: hello-world
ports:
- "80:80"
networks:
- proxynet
networks:
proxynet:
name: custom_network
docker-compose up -d will join a network called 'custom_network'. If it doesn't exist, it will be created!
root#ubuntu-s-1vcpu-1gb-tor1-01:~# docker-compose up -d
Creating network "custom_network" with the default driver
Creating root_proxy_1 ... done
Now, you can do this:
version: "2"
services:
web:
image: hello-world
networks:
- my-proxy-net
networks:
my-proxy-net:
external:
name: custom_network
This will create a container that will be on the external network.
I can't find any reference in the docs yet but it works!
Just a small adittion to #johnharris85's great answer,
when you are running a docker compose file, a "default" network is created
so you can just add it to the other compose file as an external network:
# front/docker-compose.yml
version: '2'
services:
front_service:
...
...
# api/docker-compose.yml
version: '2'
services:
api_service:
...
networks:
- front_default
networks:
front_default:
external: true
For me this approach was more suited because I did not own the first docker-compose file and wanted to communicate with it.
All containers from api can join the front default network with following config:
# api/docker-compose.yml
...
networks:
default:
external:
name: front_default
See docker compose guide: using a pre existing network (see at the bottom)
The previous posts information is correct, but it does not have details on how to link containers, which should be connected as "external_links".
Hope this example make more clear to you:
Suppose you have app1/docker-compose.yml, with two services (svc11 and svc12), and app2/docker-compose.yml with two more services (svc21 and svc22) and suppose you need to connect in a crossed fashion:
svc11 needs to connect to svc22's container
svc21 needs to connect to svc11's container.
So the configuration should be like this:
this is app1/docker-compose.yml:
version: '2'
services:
svc11:
container_name: container11
[..]
networks:
- default # this network
- app2_default # external network
external_links:
- container22:container22
[..]
svc12:
container_name: container12
[..]
networks:
default: # this network (app1)
driver: bridge
app2_default: # external network (app2)
external: true
this is app2/docker-compose.yml:
version: '2'
services:
svc21:
container_name: container21
[..]
networks:
- default # this network (app2)
- app1_default # external network (app1)
external_links:
- container11:container11
[..]
svc22:
container_name: container22
[..]
networks:
default: # this network (app2)
driver: bridge
app1_default: # external network (app1)
external: true
Everybody has explained really well, so I'll add the necessary code with just one simple explanation.
Use a network created outside of docker-compose (an "external" network) with docker-compose version 3.5+.
Further explanation can be found here.
First docker-compose.yml file should define network with name giveItANamePlease as follows.
networks:
my-network:
name: giveItANamePlease
driver: bridge
The services of first docker-compose.yml file can use network as follows:
networks:
- my-network
In second docker-compose file, we need to proxy the network by using the network name which we have used in first docker-compose file, which in this case is giveItANamePlease:
networks:
my-proxy-net:
external:
name: giveItANamePlease
And now you can use my-proxy-net in services of a second docker-compose.yml file as follows.
networks:
- my-proxy-net
Since Compose 1.18 (spec 3.5), you can just override the default network using your own custom name for all Compose YAML files you need. It is as simple as appending the following to them:
networks:
default:
name: my-app
The above assumes you have version set to 3.5 (or above if they don't deprecate it in 4+).
Other answers have pointed the same; this is a simplified summary.
UPDATE: As of docker-compose file version 3.5:
I came across a similar problem and I solved it by adding a small change in one of my docker-compose.yml project.
For instance, we have two API's scoring and ner. Scoring API needs to send a request to the ner API for processing the input request. In order to do that they both are supposed to share the same network.
Note: Every container has its own network which is automatically created at the time of running the app inside docker. For example ner API network will be created like ner_default and scoring API network will be named as scoring default. This solution will work for version: '3'.
As in the above scenario, my scoring API wants to communicate with ner API then I will add the following lines. This means Whenever I create the container for ner API then it automatically added to the scoring_default network.
networks:
default:
external:
name: scoring_default
ner/docker-compose.yml
version: '3'
services:
ner:
container_name: "ner_api"
build: .
...
networks:
default:
external:
name: scoring_default
scoring/docker-compose.yml
version: '3'
services:
api:
build: .
...
We can see this how the above containers are now a part of the same network called scoring_default using the command:
docker inspect scoring_default
{
"Name": "scoring_default",
....
"Containers": {
"14a6...28bf": {
"Name": "ner_api",
"EndpointID": "83b7...d6291",
"MacAddress": "0....",
"IPv4Address": "0.0....",
"IPv6Address": ""
},
"7b32...90d1": {
"Name": "scoring_api",
"EndpointID": "311...280d",
"MacAddress": "0.....3",
"IPv4Address": "1...0",
"IPv6Address": ""
},
...
}
You can add a .env file in all your projects containing COMPOSE_PROJECT_NAME=somename.
COMPOSE_PROJECT_NAME overrides the prefix used to name resources, as such all your projects will use somename_default as their network, making it possible for services to communicate with each other as they were in the same project.
NB: You'll get warnings for "orphaned" containers created from other projects.
So many answers!
First of all, avoid hyphens in entities names such as services and networks. They cause issues with name resolution.
Example: my-api won't work. myapi or api will work.
What worked for me is:
# api/docker-compose.yml
version: '3'
services:
api:
container_name: api
...
ports:
- 8081:8080
networks:
- mynetwork
networks:
mynetwork:
name: mynetwork
and
# front/docker-compose.yml
version: '3'
services:
front:
container_name: front
...
ports:
- 81:80
networks:
- mynetwork
networks:
mynetwork:
name: mynetwork
NOTE: I added ports to show how services can access each other, and how they are accessible from the host.
IMPORTANT: If you don't specify a network name, docker-compose will craft one for you. It uses the name of the folder the docker_compose.yml file is in. In this case: api_mynetwork and front_mynetwork. That will prevent communication between containers since they will by on different network, with very similar names.
Note that the network is defined exactly the same in both file, so you can start either service first and it will work. No need to specify which one is external, docker-compose will take care of managing that for you.
From the host
You can access either container using the published ports defined in docker-compose.yml.
You can access the Front container: curl http://localhost:81
You can access the API container: curl http://localhost:8081
From the API container
You can access the Front container using the original port, not the one you published in docker-compose.yml.
Example: curl http://front:80
From the Front container
You can access the API container using the original port, not the one you published in docker-compose.yml.
Example: curl http://api:8080
For using another docker-compose network you just do these(to share networks between docker-compose):
Run the first docker-compose project by up -d
Find the network name of the first docker-compose by: docker network ls(It contains the name of the root directory project)
Then use that name by this structure at below in the second docker-compose file.
second docker-compose.yml
version: '3'
services:
service-on-second-compose: # Define any names that you want.
.
.
.
networks:
- <put it here(the network name that comes from "docker network ls")>
networks:
- <put it here(the network name that comes from "docker network ls")>:
external: true
I would ensure all containers are docker-compose'd to the same network by composing them together at the same time, using:
docker compose --file ~/front/docker-compose.yml --file ~/api/docker-compose.yml up -d
If you are
trying to communicate between two containers from different docker-compose projects and don't want to use the same network (because let's say they would have PostgreSQL or Redis container on the same port and you would prefer to not changing these ports and not use it at the same network)
developing locally and want to imitate communication between two docker compose projects
running two docker-compose projects on localhost
developing especially Django apps or Django Rest Framework (drf) API and running app inside container on some exposed port
getting Connection refused while trying to communicate between two containers
And you want to
container api_a communicate to api_b (or vice versa) without the same "docker network"
(example below)
you can use "host" of the second container as IP of your computer and port that is mapped from inside Docker container. You can obtain IP of your computer with this script (from: Finding local IP addresses using Python's stdlib):
import socket
def get_ip():
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
try:
# doesn't even have to be reachable
s.connect(('10.255.255.255', 1))
IP = s.getsockname()[0]
except:
IP = '127.0.0.1'
finally:
s.close()
return IP
Example:
project_api_a/docker-compose.yml:
networks:
app-tier:
driver: bridge
services:
api:
container_name: api_a
image: api_a:latest
depends_on:
- postgresql
networks:
- app-tier
inside api_a container you are running Django app:
manage.py runserver 0.0.0.0:8000
and second docker-compose.yml from other project:
project_api_b/docker-compose-yml :
networks:
app-tier:
driver: bridge
services:
api:
container_name: api_b
image: api_b:latest
depends_on:
- postgresql
networks:
- app-tier
inside api_b container you are running Django app:
manage.py runserver 0.0.0.0:8001
And trying to connect from container api_a to api_b then URL of api_b container will be:
http://<get_ip_from_script_above>:8001/
It can be especially valuable if you are using even more than two(three or more) docker-compose projects and it's hard to provide common network for all of it - it's good workaround and solution
To connect two docker-compose you need a network and putting both docker-composes in that network,
you could create netwrok with docker network create name-of-network,
or you could simply put network declaration in networks option of docker-compose file and when you run docker-compose (docker-compose up) the network would be created automatically.
put the below lines in both docker-compose files
networks:
net-for-alpine:
name: test-db-net
Note: net-for-alpine is internal name of the network and it will be used inside of the docker-compose files and could be different,
test-db-net is external name of the network and must be same in two docker-compose files.
Assume we have docker-compose.db.yml and docker-compose.alpine.yml
docker-compose.apline.yml would be:
version: '3.8'
services:
alpine:
image: alpine:3.14
container_name: alpine
networks:
- net-for-alpine
# these two command keeps apline container running
stdin_open: true # docker run -i
tty: true # docker run -t
networks:
net-for-alpine:
name: test-db-net
docker-compose.db.yml would be:
version: '3.8'
services:
db:
image: postgres:13.4-alpine
container_name: psql
networks:
- net-for-db
networks:
net-for-db:
name: test-db-net
To test the network, go inside alpine container
docker exec -it alpine sh
then with following commands you could check the network
# if it returns 0 or see nothing as a result, network is established
nc -z psql (container name)
or
ping pgsql
I'm running multiple identical docker-compose.yml files in different directories, using .env files to make a slight difference. And use Nginx Proxy Manage to communicate with other services. here is my file:
make sure you have created a public network
docker network create nginx-proxy-man
/domain1.com/docker-compose.yml, /domain2.com/docker-compose.yml, ...
version: "3.9"
services:
webserver:
build:
context: ./bin/${PHPVERSION}
container_name: "${COMPOSE_PROJECT_NAME}-${PHPVERSION}"
...
networks:
- default # network outside
- internal # network internal
database:
build:
context: "./bin/${DATABASE}"
container_name: "${COMPOSE_PROJECT_NAME}-${DATABASE}"
...
networks:
- internal # network internal
networks:
default:
external: true
name: nginx-proxy-man
internal:
internal: true
.env file just change COMPOSE_PROJECT_NAME
COMPOSE_PROJECT_NAME=domain1_com
.
.
.
PHPVERSION=php56
DATABASE=mysql57
webserver.container_name: domain1_com-php56 - will join the default network (name: nginx-proxy-man), previously created for Nginx Proxy Manager to be accessible from the outside.
Note: container_name is unique in the same network.
database.container_name: domain1_com-mysql57 - easier to distinguish
In the same docker-compose.yml, the services will connect to each other via the service name because of the same network domain1_com_internal. And to be more secure, set this network with the option internal: true
Note, if you don't explicitly specify networks for each service, but just use a common external network for both docker-compose.yml, then it's likely that domain1_com will use domain2_com's database.
Another option is just running up the first module with the 'docker-compose' check the ip related with the module, and connect the second module with the previous net like external, and pointing the internal ip
example
app1 - new-network created in the service lines, mark as external: true at the bottom
app2 - indicate the "new-network" created by app1 when goes up, mark as external: true at the bottom, and set in the config to connect, the ip that app1 have in this net.
With this, you should be able to talk with each other
*this way is just for local-test focus, in order to don't do an over complex configuration
** I know is very 'patch way' but works for me and I think is so simple some other can take advantage of this
Answer for Docker Compose '3' and up
By default Docker Compose uses a bridge network to provision inter-container communication. Read this article for more info about inter-container networking.
What matters for you, is that by default Docker Compose creates a hostname that equals the service name in the docker-compose.yml file. Consider the following docker-compose.yml:
version: '3.9'
services:
server:
image: node:16.9.0
container_name: server
tty: true
stdin_open: true
depends_on:
- mongo
command: bash
mongo:
image: mongo
environment:
MONGO_INITDB_DATABASE: my-database
When you run docker-compose up, Docker will create a default network and assigns the service name as hostname for both mongo and server.
You can now access the backend container via:
docker exec -it server bash
And now you can ping the mongo container using Dockers internal network (default on port 27017 in this case):
curl -v http://mongo:27017/my-database
That's it. The same applies for your setup.
I have had a similar example where I was working with separate docker-compose files working on a docker swarm with an overlay network to do that all I had to do is change the networks parameters as so:
first docker-compose.yaml
version: '3.9'
.
.
.
networks:
net:
driver: overlay
attachable: true
docker-compose -p app up
since I have specified the app name as app using -p the initial network will be app_net.
Now in order to run another docker-compose with multiple services that will use the same network you will need to set these as so:
second docker-compose.yaml
version: '3.9'
.
.
.
networks:
net-ref:
external: true
name: app_net
docker stack deploy -c docker-compose.yml mystack
No matter what name you give to the stack the network will not be affected and will always refer to the existing external network called app_net.
PS: It's important to make sure to check your docker-compose version.
version: '2'
services:
bot:
build: .
volumes:
- '.:/home/node'
- /home/node/node_modules
networks:
- my-rede
mem_limit: 100m
memswap_limit: 100m
cpu_quota: 25000
container_name: 236948199393329152_585042339404185600_bot
command: node index.js
environment:
NODE_ENV: production
networks:
my-rede:
external:
name: name_rede_externa
Follow up of JohnHarris answer, just adding some more details which may be useful to someone: Lets take two docker-compose file and connect them through networks:
1st foldername/docker-compose.yml:
version: '2'
services:
some-contr:
container_name: []
build: .
...
networks:
- somenet
ports:
- "8080:8080"
expose:
# Opens port 8080 on the container
- "8080"
environment:
PORT: 8080
tty: true
networks:
boomnet:
driver: bridge
2nd docker-compose.yml:
version: '2'
services:
pushapiserver:
container_name: [container_name]
build: .
command: "tail -f /dev/null"
volumes:
- ./:/[work_dir]
working_dir: /[work dir]
image: [name of image]
ports:
- "8060:8066"
environment:
PORT: 8066
tty: true
networks:
- foldername_somenet
networks:
foldername_somenet:
external: true
Now you can make api calls to one another services(b/w diff containers)like:
http://pushapiserver:8066/send_push call from some code in files for 1st docker-compose.yml
Two common mistakes (atleast i made them few times):
take note of [foldername] in which your docker-compose.yml file is present. Please see above in 2nd docker-compose.yml i have added foldername in network bc docker create network by [foldername]_[networkname]
Port: this one is very common. Please note i have used 8066 when trying to make connection i.e. http://pushapiserver:8066/... 8066 is port of docker container(2nd docker-compose.yml) so when trying to talk with different docker compose.
docker will use docker container port[8066] and not host machine mapped port
[8060]

Amazon MWAA Local Runner : Where to add the Airflow variables and connections in docker-compose-local.yml

I am using Amazon MWAA local runner repository for developing and testing my dags locally before I submit a PR to main/dev branch.
I have forked it from here
I would like to export an Airflow variable and an Airflow connection as soon as I start the container : ./mwaa-local-env start
The Airflow variable : Key = deploy_environment and Value = qa
The Airflow connection : conn id = slack_conn ; conn type = HTTP ; password = *****
Something like this
I was only able to change the docker/docker-compose-local.yml to include the Airflow variable in the file.
version: '3.7'
services:
postgres:
image: postgres:10-alpine
environment:
- POSTGRES_USER=airflow
- POSTGRES_PASSWORD=airflow
- POSTGRES_DB=airflow
logging:
options:
max-size: 10m
max-file: "3"
volumes:
- "${PWD}/db-data:/var/lib/postgresql/data"
local-runner:
image: amazon/mwaa-local:2.0.2
restart: always
depends_on:
- postgres
environment:
- LOAD_EX=n
- EXECUTOR=Local
- AIRFLOW__CORE__SQL_ALCHEMY_CONN=postgresql+psycopg2://airflow:airflow#postgres:5432/airflow
- AIRFLOW_VAR_DEPLOY_ENVIRONMENT=qa
logging:
options:
max-size: 10m
max-file: "3"
volumes:
- ${PWD}/dags:/usr/local/airflow/dags
- ${PWD}/plugins:/usr/local/airflow/plugins
- $HOME/.aws/credentials:/usr/local/airflow/.aws/credentials:ro
ports:
- "8080:8080"
command: local-runner
healthcheck:
test: ["CMD-SHELL", "[ -f /usr/local/airflow/airflow-webserver.pid ]"]
interval: 30s
timeout: 30s
retries: 3
I thought AIRFLOW_VAR_DEPLOY_ENVIRONMENT=qa would do the job. However this is what I get after I start Airflow environment.
For adding an Airflow connection, I have not been able to figure out how to export that in docker-compose-local.yml
Any help in exporting the above two is appreciated!
The connection information can be stored as a JSON string in the environment variable. Not all of the keys are required. Only provide what's needed for the Slack provider module.
export AIRFLOW_CONN_SLACK_CONN='{
"conn_type": "my-conn-type",
"login": "my-login",
"password": "my-password",
"host": "my-host",
"port": 1234,
"schema": "my-schema",
"extra": {
"param1": "val1",
"param2": "val2"
}
}'
You can also store the connection information in URI format in the environment variable.
export AIRFLOW_CONN_SLACK_CONN='my-conn-type://login:password#host:port/schema?param1=val1&param2=val2'
The environment variable name must be prefixed with AIRFLOW_CONN_.
Reference: Storing connections in environment variables (Airflow)

nextjs + react-env: how to pass env variables from docker compose

I am using the https://github.com/andrewmclagan/react-env way to pass env variables to browser. I am able to do using .env file, but not through the docker compose
I have a docker compose file. I have to set the api url for the nextjs project
node_nextjs:
image: "node16_build_custom"
ports:
- 3000:3000
environment:
- DS_PATH=/home/simha/app/torsha_datasets
- REACT_APP_API_HOST=http://localhost:8000
volumes:
- type: bind
source: ../CODE/nextjs_frontend
target: /home/simha/app
command:
- sh
- -c
- |
id
yarn react-env
pm2-runtime npm -- start
stdin_open: true # Add this line into your service
tty: true # Add this line into your service
networks:
- nginx_network
I am setting the REACT_APP_API_HOST=http://localhost:8000 in the docker compose
but yarn react-env does not create the env variable inside public/__ENV.js
I see
window.__ENV = {};
How to pass the docker compose env varialbe inside .env file
i tried
.env
REACT_APP_API_HOST=$REACT_APP_API_HOST
This does not work.

Docker is not getting Postgres environment variables

Docker is using the variables from my .env file and i keep getting the error:
Unhandled rejection SequelizeConnectionError: role "eli" does not
exist
I would like for Postgres to get the variables from the environment set in docker-compose.yml
.env
POSTGRES_PORT=5432
POSTGRES_DB=elitest4
POSTGRES_USER=eli
POSTGRES_PASSWORD=
docker-compose.yml
# docker-compose.yml
version: "3"
services:
app:
build: .
depends_on:
- database
ports:
- 8000:8000
environment:
- POSTGRES_HOST=database
env_file:
- .env
database:
image: postgres:9.6.8-alpine
environment: # postgress should be getting these variables, not the variables set in the env file thats for localhost
POSTGRES_PASSWORD: password
POSTGRES_USER: user
POSTGRES_DB: db
volumes:
- pgdata:/var/lib/postgresql/pgdata
ports:
- 8002:5432
env_file:
- .env
react_client:
build:
context: ./client
dockerfile: Dockerfile
image: react_client
working_dir: /home/node/app/client
volumes:
- ./:/home/node/app
ports:
- 8001:8001
env_file:
- ./client/.env
volumes:
pgdata:
TL/DR
Try updating the docker-compose service database environment section as follows:
environment:
POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-password}
POSTGRES_USER: ${POSTGRES_USER:-user}
POSTGRES_DB: ${POSTGRES_DB:-db}
Also notice that if you would like to see how each bound variable ultimately evaluates in Compose you can run the following command to see the "effective" compose file:
$ docker-compose config
This command will print out what your compose file looks like with all variable substitution replaced with its evaluation.
See the Environment variables in Compose and the Variable substitution sections in the documentation.
Pay close attention to this section:
When you set the same environment variable in multiple files, here’s
the priority used by Compose to choose which value to use:
1. Compose file
2. Shell environment variables
3. Environment file Dockerfile
4. Variable is not defined
In the example below, we set the same environment variable on an Environment file, and the Compose file:
$ cat ./Docker/api/api.env
NODE_ENV=test
$ cat docker-compose.yml
version: '3'
services:
api:
image: 'node:6-alpine'
env_file:
- ./Docker/api/api.env
environment:
- NODE_ENV=production
When you run the container, the environment variable defined in the Compose file takes precedence.
$ docker-compose exec api node
process.env.NODE_ENV 'production'
Having any ARG or ENV setting in a Dockerfile evaluates only if there is no Docker Compose entry for environment or env_file.
Specifics for NodeJS containers
If you have a package.json entry for script:start like NODE_ENV=test node server.js, then this overrules any setting in your docker-compose.yml file.

docker stack: setting environment variable from secrets

I was trying to set the password from secrets but it wasn't picking it up.
Docker Server verions is 17.06.2-ce. I used the below command to set the secret:
echo "abcd" | docker secret create password -
My docker compose yml file looks like this
version: '3.1'
...
build:
context: ./test
dockerfile: Dockerfile
environment:
user_name: admin
eureka_password: /run/secrets/password
secrets:
- password
I also have root secrets tag:
secrets:
password:
external: true
When I hardcode the password in environment it works but when I try via the secrets it doesn't pick up. I tried to change the compose version to 3.2 but with no luck. Any pointers are highly appreciated!
To elaborate on the original accepted answer, just change your docker-compose.yml file so that it contains this as your entrypoint:
version: "3.7"
services:
server:
image: alpine:latest
secrets:
- test
entrypoint: [ '/bin/sh', '-c', 'export TEST=$$(cat /var/run/secrets/test) ; source /entrypoint.sh' ]
secrets:
test:
external: true
That way you don't need any additional files!
You need modify docker compose to read the secret env file from /run/secrets. If you want to set environment variables via bash, you can overwrite your docker-compose.yaml file as displayed below.
You can save the following code as entrypoint_overwrited.sh:
# get your envs files and export envars
export $(egrep -v '^#' /run/secrets/* | xargs)
# if you need some specific file, where password is the secret name
# export $(egrep -v '^#' /run/secrets/password| xargs)
# call the dockerfile's entrypoint
source /docker-entrypoint.sh
In your docker-compose.yaml overwrite the dockerfile and entrypoint keys:
version: '3.1'
#...
build:
context: ./test
dockerfile: Dockerfile
entrypoint: source /data/entrypoint_overwrited.sh
tmpfs:
- /run/secrets
volumes:
- /path/your/data/where/is/the/script/:/data/
environment:
user_name: admin
eureka_password: /run/secrets/password
secrets:
- password
Using the snippets above, the environment variables user_name or eureka_password will be overwritten. If your secret env file defines the same env vars, the same will happen if you define in your service some env_file.
I found this neat extension to Alejandro's approach: make your custom entrypoint load from ENV_FILE variables to ENV ones:
environment:
MYSQL_PASSWORD_FILE: /run/secrets/my_password_secret
entrypoint: /entrypoint.sh
and then in your entrypoint.sh:
#!/usr/bin/env bash
set -e
file_env() {
local var="$1"
local fileVar="${var}_FILE"
local def="${2:-}"
if [ "${!var:-}" ] && [ "${!fileVar:-}" ]; then
echo >&2 "error: both $var and $fileVar are set (but are exclusive)"
exit 1
fi
local val="$def"
if [ "${!var:-}" ]; then
val="${!var}"
elif [ "${!fileVar:-}" ]; then
val="$(< "${!fileVar}")"
fi
export "$var"="$val"
unset "$fileVar"
}
file_env "MYSQL_PASSWORD"
Then, when the upstream image changes adds support for _FILE variables, you can drop the custom entrypoint without making changes to your compose file.
One option is to map your secret directly before you run your command:
entrypoint: "/bin/sh -c 'eureka_password=`cat /run/secrets/password` && echo $eureka_password'"
For example MYSQL password for node:
version: "3.7"
services:
app:
image: xxx
entrypoint: "/bin/sh -c 'MYSQL_PASSWORD=`cat /run/secrets/sql-pass` npm run start'"
secrets:
- sql-pass
secrets:
sql-pass:
external: true
Because you are initialising the eureka_password with a file instead of value.