From: Tom Clegg <tom@tomclegg.ca>
Date: Thu, 6 Feb 2020 16:09:32 +0000 (-0500)
Subject: 16133: Don't take multiple hops when getting collections.
X-Git-Tag: 2.0.0~11^2~1
X-Git-Url: https://git.arvados.org/arvados.git/commitdiff_plain/14bb7aa24ed7a06ce94e59f64ab32bdb44641168

16133: Don't take multiple hops when getting collections.

Arvados-DCO-1.1-Signed-off-by: Tom Clegg <tom@tomclegg.ca>
---

diff --git a/lib/controller/federation/conn.go b/lib/controller/federation/conn.go
index 4d4141ffd6..2aebc0e970 100644
--- a/lib/controller/federation/conn.go
+++ b/lib/controller/federation/conn.go
@@ -231,7 +231,13 @@ func (conn *Conn) CollectionGet(ctx context.Context, options arvados.GetOptions)
 		// UUID is a PDH
 		first := make(chan arvados.Collection, 1)
 		err := conn.tryLocalThenRemotes(ctx, func(ctx context.Context, remoteID string, be backend) error {
-			if remoteID != "" && strings.Contains(downstream, remoteID) {
+			if remoteID != "" && downstream != "" {
+				// If remoteID isn't in downstream, we
+				// might find the collection by taking
+				// another hop, but we don't bother:
+				// token salting and blob signature
+				// rewriting don't work over multiple
+				// hops.
 				return notFoundError{}
 			}
 			c, err := be.CollectionGet(ctx, options)