pgBackRest with backup uploads to S3 behind HTTP proxy

pgBackRest does not support HTTP proxies (in its S3 client). This was raised on Github couple of times ([1], [2], [3], [4]).

Suggested workaround is to use ProxyChains.

Discovering you need to slap some extra component into a critical path of a critical workflow is exciting... Exciting as in need-to-go-to-a-dentist kind of exciting.

But happy to confirm that it just works! With Squid on the other end.

End of story - for now.