How to dynamically set environment variables (envs.ENV.env-vars)?

[ketozhang]

Is there any way to dynamically set environment variables?

In my use case, I want to set a secret variable dynamically using a command that takes in another env var for the secret key/name.

[tool.hatch.envs.default.env-vars]
SECRET_KEY="some-key-name"
SECRET="$(get-secret $SECRET_KEY)"  # get-secret is a placeholder command

The only way I can think of is to set it in scripts.

[tool.hatch.envs.default.scripts]
test="SECRET=$(get-secret $SECRET_KEY) printenv"

...which does not scale, unless you can use secret="export SECRET=..." then test=["secret", "printenv"], but I don't think hatch preserves export.

[ofek]

Hatch doesn't preserve exports because it's a different process for each command but you can instead do shell syntax like test=["secret && stuff"].

I will think of a way to support dynamic environment variables based on the output of commands, thanks! Please create an issue/feature request for that.

[ketozhang]

Today I tried this again replacing && with ; and hatch wasn't able to find the script.

setup = "docker compose up -d --wait"
teardown = "docker compose down"
test = ["setup; pytest; teardown"]

/bin/sh: setup: command not found
==================================================== test session starts ====================================================
platform darwin -- Python 3.12.4, pytest-8.2.2, pluggy-1.5.0
rootdir: REDACTED
configfile: pytest.ini
collected 0 items

=================================================== no tests ran in 0.01s ===================================================
/bin/sh: teardown: command not found

[ofek]

the way scripts work is that the part before the first space is replaced, try turning your test command into a list of strings instead

[ketozhang]

Gotcha that makes sense otherwise the logic behind replacement would be unwieldy (alternatively, scripts gets injected into HATCH_HOME/env/virtual/project_name/hash/bin/). IIRC, the teardown step does not get performed if pytest exits non-zero in this situation (which is why I replaced && with ;, to guarantee teardown always runs)

...but we can use this hack:

test = ["setup", "pytest || true", "teardown"]

Back in the scope of the OP, the environment variables are also not preserved using list of strings.