Python 3 Support

[aneeshusa]

Does NixOps support Python 3? I couldn't tell from setup.py or the issues, but it looks like it's Python 2 only right now. (I'm waiting for #502 so I can try nixops out.)

I think this would be nice to go along with NixOS/nixpkgs#18185.

[domenkozar]

It doesn't support it yet.

[aske]

I can try migrating NixOps to python3 (looks like we'll need to use boto3 library; need to check libraries used for non-AWS backends before that, though).

[aske]

I'll make the PR to explicitly set python 2 version so we can move further with moving to python3 by default a bit later.

Alright, the rough roadmap right now looks like this:

1. Migrate to boto3
2. Upgrade/move to other libs for non-AWS backends
3. Migrate tests to nose2 (or py.test?)
4. Do the actual 2->3 migration

[aske]

Also, cc @edolstra @rbvermaa I guess, in case they have any comments.

[domenkozar]

@aske the plan sounds good. I'd keep nose2 for having a small scope for this somewhat big task.

[domenkozar]

Boto3 migration guide: http://boto3.readthedocs.io/en/latest/guide/migration.html

[aske]

I hope I'll be able to start working on migrating to boto3 this or next weekend (was a bit swamped with work).

[bachp]

I don't think nixops needs to support python2 along side python3. I assume it is mostly installed vis nixpkgs which already has python3 and it can easily be switched there.

Please correct me if I'm wrong.

[edolstra]

Yeah, I don't think there's any reason to keep supporting Python 2.

[teto]

Any news on the python3 front ? is there a PR one can follow/help with ?

[domenkozar]

First we need to migrate to boto3 as per checklist from @aske.

[aske]

Hm, hackathon at NixCon looks like the perfect opportunity to finally start working on this.

[domenkozar]

Small boto3 progress: #749

[davidak]

The clock is ticking...

[takeda]

So I pulled the trigger and made somewhat large changes in moving everything to boto3 the dependency is still there, but hopefully there's not much left. The changes I did though require testing, so if anyone could find issues and show the command and backtrace, that might help me fix them.

#1186

I also added typing information to the functions/methods that I touched so hopefully it will also help migrating to python 3 and find bugs in the code.

[takeda]

I moved my commits into a new nixops-aws repo: NixOS/nixops-aws#1 since my old PR is no longer valid after dividing nixops into modules.

[asymmetric]

Should we close this then?

---

EDIT It seems there are some changes needed on nixops itself, so this shouldn't be closed yet, sorry.

[davidak]

Should we close this then?

This issue is not yet solved, so no!

Python 2.7 will not be maintained past 2020.

https://pythonclock.org/

So, to make this tool usable and maintainable past next year, we need to migrate it! We have 3 months and 15 days left...

[takeda]

@asymmetric this patch doesn't make nixops python 3 complaint, it targets the dependence on boto which is python 2 only (and no longer supported AFAIK). The changes mentioned in that old PR was splitting nixops into modules so I redone my PR to just target nixops-aws.

@davidak with how things are moving I don't think we will make it in 3 months :) but it's not like python2.7 suddenly will stop from working, although new versions of packages will start breaking as maintainers will stop caring about 2.7.

[grahamc]

NixOps is now python3 only.

[jonringer]

it would be nice to expose the python3 version in nixpkgs, seeing as I would like to stop fixing python2 packages to ensure nixopsUnstable still builds with the python2 package set. NixOS/nixpkgs#95609 (comment)

plus it would be nice for the 20.09 release to not have a version based on an EOL python interpreter

[nixos-discourse]

This issue has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/new-nixos-org-design/9080/33

[dotlambda]

Are there any plans to make the Python 3 versions of NixOps the default for 21.05?

[mweinelt]

Or for 21.11?