CODEWITHSUNDEEP
dockerdocker-compose
Dancrumb
Dancrumb

Reputation: 27539

Can you define optional docker-compose services?

Is there a way to define a Docker Compose service such that it is only brought up when you explicitly request it?

That is to say:

docker-compose up

would not start it, but

docker-compose up optional_service

would.

Upvotes: 62

Views: 25534

Answers (3)

yoannisj
yoannisj

Reputation: 986

Docker compose now supports profiles, which allow you to a) disable one or more services by default, and b) enable them when docker compose is ran with the corresponding --profile argument.

This is done by adding a profiles key to your service in the docker-compose.yml file. Services that have don't have this key are always started by docker-compose (for all profiles).

For example, with the following docker-compose.yml file

version: '3.9'
services
  app_service:
    # ...
  test_service:
    profiles:
      - testing
    # ...

Running docker-compose up will only start the app_service, and running docker-compose --profile testing up will start both the app_service and the test_service.

Multiple profiles can be specified by passing multiple --profile flags.

More info can be found here: https://docs.docker.com/compose/profiles/

Edit: I had to update to docker engine v20.10.5 for this to work.

Upvotes: 87

eshaan7
eshaan7

Reputation: 1068

The extend keyword has been removed in version 3.x.

I faced the same issue and this is what I did:

  • From Docker's official docs, we can use a COMPOSE_FILE environment variable in a .env file.
  • The way this works is: when you do docker-compose up, instead of reading docker-compose.yml, it will read all the compose files specified in COMPOSE_FILE variable.

For example,

COMPOSE_FILE=docker-compose.yml:./optional/docker-compose.prod.yml
  • the good part is that:
    • the .env file is auto-read (if located in the same level as docker-compose.yml), when we invoke docker-compose up.
    • no need to specify each file with a -f flag in CLI.
  • The one drawback is: need to create separate compose files for each service you wish to make optional.

Note: separate file names with a : in case of linux or ; in case of windows.

Upvotes: 19

ivan.sim
ivan.sim

Reputation: 9268

One way to achieve that is to define your optional service in a different compose file. Then to start the optional service, run:

$ docker-compose -f docker-compose.yml -f optional-service.yaml up

For example, if I have a docker-compose.yml file that looks like:

version: '2.1'
services:
  lb:
    image: nginx:1.13           
  db:
    image: redis:3.2.9

I can extend it with an optional-service.yml that looks like:

version: '2.1'
services:
  busy:
    image: busybox

Notice that both compose files must use the same Compose file version.

You can read more about it in the Compose documentation.

Upvotes: 39

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