Fixes

Fixes #2938 by @stacimc

Description

This PR updates the env recipe to make it "smarter". Instead of copying over the file and overwriting changes, the Python script now keeps changed env values and even extra env key-value pairs in the file.

Assume the following env.template file:

key_one=value_one
key_two=value_two

Assume the following .env file:

key_one=new_value_one
key_three=value_three

After just env the .env file would be as follows.

key_one=new_value_one
key_two=value_two

# Preserved variables
key_three=value_three

Testing Instructions

0. Make some changes to the catalog/.env file. You could change some values, delete some keys or add some new keys.
1. Run just env.
2. See that the changes are preserved, deleted keys are restored and custom extra keys are kept at the bottom of the file.
3. Confirm this against the printed logs.

Shortcomings

This approach does not preserve any extra comments in the .env file. Those will be deleted.

Checklist

• My pull request has a descriptive title (not a vague title likeUpdate index.md).
• My pull request targets the default branch of the repository (main) or a parent feature branch.
• My commit messages follow best practices.
• My code follows the established code style of the repository.
• I added or updated tests for the changes I made (if applicable).
• I added or updated documentation (if applicable).
• I tried running the project locally and verified that there are no visible errors.
• I ran the DAG documentation generator (ov just catalog/generate-docs for catalog
  PRs) or the media properties generator (ov just catalog/generate-docs media-props
  for the catalog or ov just api/generate-docs for the API) where applicable.

Developer Certificate of Origin

Developer Certificate of Origin
Version 1.1

Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
1 Letterman Drive
Suite D4700
San Francisco, CA, 94129

Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.


Developer's Certificate of Origin 1.1

By making a contribution to this project, I certify that:

(a) The contribution was created in whole or in part by me and I
    have the right to submit it under the open source license
    indicated in the file; or

(b) The contribution is based upon previous work that, to the best
    of my knowledge, is covered under an appropriate open source
    license and I have the right under that license to submit that
    work with modifications, whether created in whole or in part
    by me, under the same open source license (unless I am
    permitted to submit under a different license), as indicated
    in the file; or

(c) The contribution was provided directly to me by some other
    person who certified (a), (b) or (c) and I have not modified
    it.

(d) I understand and agree that this project and the contribution
    are public and that a record of the contribution (including all
    personal information I submit with it, including my sign-off) is
    maintained indefinitely and may be redistributed consistent with
    this project or the open source license(s) involved.