Add a github action to sync shared source from aspnetcore

[Tratcher]

This mirrors an action we have in aspnetcore to sync changes to shared HTTP source code files.
https://github.com/dotnet/aspnetcore/actions/workflows/runtime-sync.yml

The one in aspnet triggers on a nightly schedule and sends a PR to aspnetcore if it detects any diffs. However, sometimes changes need to be submitted to runtime instead. The new action added here will only trigger manually, and will send a pr to runtime with any diffs.

[ghost]

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Issue Details

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This mirrors an action we have in aspnetcore to sync changes from shared HTTP source code files.
https://github.com/dotnet/aspnetcore/actions/workflows/runtime-sync.yml

The one in aspnet triggers on a nightly schedule and sends a PR to aspnetcore if it detects any diffs. However, sometimes changes need to be submitted to runtime instead. The new action added here will only trigger manually, and will send a pr to runtime with any diffs.

Author:	Tratcher
Assignees:	Tratcher
Labels:	area-System.Net.Http
Milestone:	-

[JamesNK]

A couple of questions:

• How is the sync triggered?
• How are reaction changes on the PR added? For example, a sync change renames a method and runtime code needs to react to that.

[Tratcher]

A couple of questions:

• How is the sync triggered?

It's triggered manually from the https://github.com/dotnet/runtime/actions page. Compare to this one that has a "Run Workflow" option: https://github.com/dotnet/runtime/actions/workflows/create-codespaces-prebuild.yml

• How are reaction changes on the PR added? For example, a sync change renames a method and runtime code needs to react to that.

You'd check out the branch and push additional changes.

[JamesNK]

I don't know anything about github actions.

This approve is moral support for the feature 😄

[Tratcher]

FYI, here is an example of the issue and PR the runtime->aspnetcore version of this script generates:
dotnet/aspnetcore#18943 (comment)
dotnet/aspnetcore#38614

This is also a case where the changes need to go into runtime instead. The new aspnetcore->runtime script only generates a PR in runtime, it references the same issue in aspnetcore.

[safern]

Is this extra file needed? We could just inline this command in the gh action?

Also, I wonder if using git diff would be easier? Something like

git diff -M -C -b --ignore-cr-at-eol --ignore-space-at-eol --exit-code > ..\artifacts\diff.txt
$changed = !$?

The only issue I see with git diff are untracked files, so we would need to run git add -N . before running the command. Just an idea to consider.

[Tratcher]

I guess the aspnetcore version of this file did a lot more to open and comment on the github issue. Inlining just this part might be easier now.
https://github.com/dotnet/aspnetcore/blob/main/.github/workflows/ReportDiff.ps1

[ManickaP]

Love the idea, thanks for submitting this!

[Tratcher]

I'm going to merge this so we can do a live test, and then iterate on feedback.