Allow pull requests from Github

[tobiasdiez]

I've heard that once upon a time there was a bot that created trac issues based on GitHub PRs. Apparently the bot was lost.

I found https://github.com/trac-hacks/trac-github which has the feature to "update the local git mirror used by Trac after each push to GitHub, and notify the new changesets to Trac;". Sounds like this is exactly what would be needed to allow PRs from github.
I couldn't find anything on how to install trac plugins here on sage.

Related:

• Meta-ticket: Migration from Trac to GitHub #30363: Migrate to GitHub

Depends on #30363

CC: @embray @mkoeppe @robertwb @slel @williamstein

Component: misc

Issue created by migration from https://trac.sagemath.org/ticket/30406

[davidlowryduda]

comment:1

Is this functionality that we want? There are several warnings about how the sage github repo doesn't accept PRs and to instead use trac.

[davidlowryduda]

comment:2

Ah, only now do I see that this is morally a continuation of the commentary occuring in #30363

[tobiasdiez]

comment:3

Thanks for the link, I had forgotten where I read about the lost bot.

[embray]

comment:4

We are accepting merge requests through GitLab: https://gitlab.com/sagemath/sage

The GitHub page should link to that.

[mkoeppe]

comment:6

Setting new milestone based on a cursory review of ticket status, priority, and last modification date.

[slel]

comment:7

The bot to turn pull requests to the SageMath repo at GitHub
into Trac tickets once existed.

In a 2014-08 sage-devel discussion, Robert described:

All pull requests on github turn into tickets, so this easy web
interface flow works now.

The bot stopped working around mid 2015.

In a 2016-07 sage-devel discussion, Paul wrote:

[...] there are a couple pull requests from the middle of 2015 that never became
Trac tickets. The bot appears to have stopped creating tickets before then.

There are open pull requests from the end of 2014 that became part of Sage 6.4.
The bot does not appear to close pull requests on GitHub.

and Robert wrote:

I was running a small script on trac.sagemath.org:12000 that was
listening for github pull requests and comments (via github webhooks)
and publishing them to trac (via the trac scripts shipped with Sage).
Nothing too fancy, but I can't find the code for it at the moment (but
it's probably still sitting in that image unless it's been redone
since then). I don't remember if I ever pushed anything back to github
(which would require write access) but pull requests should get closed
when their associated changes get merged into master.

In a 2018-02 discussion on the sagemath-admins mailing list, Robert wrote:

Sorry, I have no idea where the source to that is. However, the whole
thing was like 100 lines or so. It just listened for github hooks and
posted the information to a new/existing ticket on trac, and vice
versa (maybe was invoked via patchbot when something changed, I don't
remember how the hooks went the other direction).

At this point, probably less effort to re-implement than track it
down. Huge +1 to tighter github integration; using trac to push
changes at the very least is a huge barrier for casual development.
(I'm very happy with migrating Cython completely over to Github,
modulo I don't keep track of the jenkins server that used to regularly
build and test Sage with Cython head).

[slel]

comment:8

Christopher Swenson pointed me to this:

https://github.com/swenson/sage-workflow/blob/master/sagedev/pr_export.py

[embray]

comment:10

If you really want to do this I would recommend looking at the gitlab hook in the Trac plugin (ironically still hosted on GH though I would prefer to move it): https://github.com/sagemath/sage_trac_plugin/blob/master/sage_trac/gitlab.py

Most of this could be refactored to abstract out the GitLab and GitHub API differences. Personally I am not motivated to do it though.

[kwankyu]

comment:12

Though we migrate to github, trac may function as a secondary issue tracker or at least archiver if this ticket is achieved. Or would we close trac completely after the migration?

[mkoeppe]

comment:13

I would think we would probably keep Trac around in read-only mode for a little while, just so that people can easily see that nothing has been lost in the conversion. But definitely not more than that. Definitely not a converter from GH to Trac.

[mkoeppe]

Dependencies: #30363

[williamstein]

comment:15

We would not want to break links to trac somehow. Eg we could host all of trac.sagemath.org in static readonly mode (e.g via github pages) forever to preserve the links.

[mkoeppe]

comment:16

Or set up http redirects to the Issues? The plan is to map them 1:1

[mkoeppe]

comment:17

I've added these ideas to #30363, let's take the discussion there.