Problems with .env variables referencing other .env variables

[matgnt]

It turned out, docker-compose 1.25.0 and other older versions don't support this.

We should either (somehow) check and stop the starting process, or don't use them and instead fully write down the variable content, e.g.
.env-example:

BPA_PROFILE_ENDPOINT=https://${BPA_HOST}/profile.jsonld

vs.

BPA_PROFILE_ENDPOINT=https://localhost/profile.jsonld

[domwoe]

If look through .env-example I see the following cases:

BPA_PROFILE_ENDPOINT=https://${BPA_HOST}/profile.jsonld

LEDGER_URL=https://indy-test.bosch-digital.de
BPA_LEDGER_BROWSER=${LEDGER_URL}

AGENT_HTTP_PORT=8030
AGENT_ADMIN_PORT=8031
AGENT_ENDPOINT=http://${BPA_HOST}:${AGENT_HTTP_PORT}
ACAPY_ADMIN_URL=http://aca-py:${AGENT_ADMIN_PORT}
ACAPY_AGENT_URL=http://aca-py:${AGENT_HTTP_PORT}

Except the middle case (LEDGER_URL and BPA_LEDGER_BROWSER) which might make sense to configure them independently, I'd say the other ones are directly dependent. Couldn't we just move

BPA_PROFILE_ENDPOINT=https://${BPA_HOST}/profile.jsonld

AGENT_ENDPOINT=http://${BPA_HOST}:${AGENT_HTTP_PORT}
ACAPY_ADMIN_URL=http://aca-py:${AGENT_ADMIN_PORT}
ACAPY_AGENT_URL=http://aca-py:${AGENT_HTTP_PORT}

inside the docker-compose.yml and change the .env to the following?

LEDGER_URL=https://indy-test.bosch-digital.de
BPA_LEDGER_BROWSER=https://indy-test.bosch-digital.de