tree a1e5341a9b71f973e1c24734872b0e1cc897f93c
parent c89df2f0de65533e0801c6472cc4cee8b13cd761
author Serge Bazanski <serge@nexantic.com> 1623095934 +0200
committer Sergiusz Bazanski <serge@nexantic.com> 1623110526 +0000

m/pkg/combinectx: implement

This implements combinectx, a Go library for combining two contexts into
a single one. We need this for the new curator logic (where we want to
cancel RPC calls both when the incoming request gets canceled but also
when leadership status changes), and this functionality has been
factored out as a reusable, generic library.

Prior art:

1) https://github.com/golang/go/issues/36503
   Proposal to add Merge() to context stdlib package. Unimplemented.

2) https://github.com/teivah/onecontext
   Complex reflect-based logic for arbitrary amount of contexts to join,
   no functionality to detect which context caused the joined context to
   be canceled.

3) https://github.com/LK4D4/joincontext
   No functionality to detect which context caused the joined context to
   be canceled.

Change-Id: I774607da38b06c192ff0fee133eb258abd500864
Reviewed-on: https://review.monogon.dev/c/monogon/+/123
Reviewed-by: Leopold Schabel <leo@nexantic.com>