Environment variable interpolation not working

Feedback & Bug Reports
1

Hello,

I’m trying to interpolate an environment variable within another one as it’s stated in the project configuration UI (Environment variables section).

No matter which variable I use (even the example: ${HOME}) it’s always escaped (\$HOME). I’m using export as a build step to print all the environment variables and debug it.

2

May we see the whole of your config file? I take it you’re using Circle 2.0?

Note that env vars don’t work in all parts of a file. For example, they do work in commands, but they don’t work in cache key definitions.

3

https://github.com/hugomarisco/circle-test/blob/master/.circleci/config.yml

here is my configuration file

And here is a screenshot of how I’m trying to add an environment variable:

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Screen Shot 2018-02-27 at 13.34.49.png1408×702 45.7 KB

And here is the result: https://imgur.com/a/9Qwot (I can’t upload more than one image per post with my permissions on this forum)

Thank you for your help

4

Righto, so you’re trying to set API_URL equal to another variable. I don’t know if that works from the dialogue box, but the help text says it should!

If I were debugging this, I would try these:

  • Swap ${CIRCLE_BRANCH} in that dialogue box for a non-variable value. Does that work? If it does, then maybe this dialogue only works for things that exist forever (e.g. $HOME) and the one you are trying to use is created too late to be interpolated correctly?
  • Consider deleting this var and adding API_URL=${CIRCLE_BRANCH} in an early run step in your config file instead.
  • If that does not work, try putting export in front of it. I am not an expert on env var behaviour, but I believe this can make a difference when wanting env vars to be exposed to new processes.

Let us know how you get on.

5

Hello,

Your assumptions are right and after carefully reading the 2.0 docs about this matter I found this: https://circleci.com/docs/2.0/env-vars/#interpolating-environment-variables-to-set-other-environment-variables

So I’m simply writing the variables I need to $BASH_ENV in a build step and I can now access them on later steps.

Thank you once again for your time, really appreciated

1 Like
6

Great stuff! I believe you can mark your answer above as the solution by clicking the ‘solved’ widget just below it - that may be useful for a future reader.