Use relative paths in generated Dockerfile

[pravindahal]

Thanks for contributing to Prefect!

Please describe your work and make sure your PR:

• adds new tests (if appropriate)
• add a changelog entry in the changes/ directory (if appropriate)
• updates docstrings for any new functions or function arguments, including docs/outline.toml for API reference docs (if appropriate)

What does this PR change?

Before the fix, in the temporary Dockerfile that is created when using Docker storage for a flow, full paths to files are inserted. This causes docker build to fail as reported here: #3023

[marvin-robot]

Here I am, brain the size of a planet and they ask me to welcome you to Prefect.

So, welcome to the community @pravindahal! 🎉 🎉

[codecov]

Codecov Report

Merging #3035 into master will increase coverage by 0.00%.
The diff coverage is 100.00%.

[thomasfrederikhoeck]

I think you still want to have the option for absoulte if you are using Docker for windows without SSH hence it should maybe be
if sys.platform == "win32" and not self.base_url.startswith("ssh://"):
at this location:

prefect/src/prefect/environments/storage/docker.py

Line 343 in e83e838

if sys.platform == "win32":

[pravindahal]

@thomasfrederikhoeck I am using Docker for Windows using wsl2 backend. So, self.base_url starts with npipe:/// for me.

EDIT: Also, there is no downside to always having relative paths, IMO.

[joshmeek]

@pravindahal it looks like your local git may not be authenticated with your github account (commits are showing up as grey octocat logo):

If you want you could try this:
https://docs.github.com/en/enterprise/2.18/user/github/committing-changes-to-your-project/why-are-my-commits-linked-to-the-wrong-user#commits-are-not-linked-to-any-user
https://docs.github.com/en/github/setting-up-and-managing-your-github-user-account/setting-your-commit-email-address#setting-your-commit-email-address-in-git

Also going to tag @lauralorenz if she wants to test this windows side 🙂

[pravindahal]

@joshmeek Thanks for pointing out. My git client was using my company email, which I hadn't added to github. Fixed it now.

[thomasfrederikhoeck]

@pravindahal I agree that there should be no downsides to relative paths. However it is worth noticing this comment (which leads me to suspect that someone has tried working on it before):

prefect/src/prefect/environments/storage/docker.py

Line 356 in f250e90

# problem with docker and relative paths only on windows

It might be worth testing out if the relative paths work on the legacy Hyper-V backend :-)

[pravindahal]

@thomasfrederikhoeck I went back and found out the change here #2390 addresses the exact same issue.

I will come back with an updated fix.

[pravindahal]

I think I found the real problem, which is with the dockerfile parameter to client.build. I will close this and open a new PR.

[pravindahal]

New PR here: #3044