docker-compose args from shell

Question

I want to build via the docker-compose an image that uses my private key for cloning private git repos.

More or less the compose becomes as fol

Answer 1

One way to do it that will work when building all the services and also with up is to pass the SSH key data as an environnement variable like this:

env RSA=$(cat ~/.ssh/id_rsa) docker-compose build

And then you set the build args in the compose file like this:

myservice:
 build:
  context: .
  args:
    RSA: |-
      ${RSA}