tree 561f648952e5a39cd3947aff540e33119cc02834
parent 5fa14a31b0b4bd95cf10a1394d2322db110b25b4
author Russ Cox <rsc@golang.org> 1556052584 -0400
committer Russ Cox <rsc@golang.org> 1556204049 +0000

cmd/go: add support for GOPROXY list

Following discussion on golang.org/issue/26334, this CL changes
the GOPROXY environment setting to be a list of proxies, tried in
sequence. The first successful or non-404/410 error is taken as
authoritative. Otherwise the next proxy is tried, and so on.

As in earlier releases, GOPROXY=direct means "connect directly",
but now it can appear in a longer list as well.

This will let companies run a proxy holding only their private modules
and let users set GOPROXY=thatproxy,publicproxy or GOPROXY=thatproxy,direct
to fall back to an alternate mechanism for fetching public modules.

Fixes #26334.

Change-Id: I642f0ae655ec307d9cdcad0830c0baac8670eb9c
Reviewed-on: https://go-review.googlesource.com/c/go/+/173441
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>