From a211b681ad75ed05c33198c3ea806652ccf9d78f Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Fri, 25 Sep 2020 16:16:28 +0200
Subject: [PATCH] backend-common: use localhost to fall back to IPv4 if IPv6
 isn't available

---
 packages/backend-common/src/discovery/SingleHostDiscovery.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/packages/backend-common/src/discovery/SingleHostDiscovery.ts b/packages/backend-common/src/discovery/SingleHostDiscovery.ts
index 1970583e5f..184746b924 100644
--- a/packages/backend-common/src/discovery/SingleHostDiscovery.ts
+++ b/packages/backend-common/src/discovery/SingleHostDiscovery.ts
@@ -49,7 +49,10 @@ export class SingleHostDiscovery implements PluginEndpointDiscovery {
     // Translate bind-all to localhost, and support IPv6
     let host = listenHost;
     if (host === '::') {
-      host = '::1';
+      // We use localhost instead of ::1, since IPv6-compatible systems should default
+      // to using IPv6 when they see localhost, but if the system doesn't support IPv6
+      // things will still work.
+      host = 'localhost';
     } else if (host === '0.0.0.0') {
       host = '127.0.0.1';
     }