From 2dff21660b68b237e88b5928429b008a47e2d6f2 Mon Sep 17 00:00:00 2001
From: Ian Bishop <151477169+ianb-mp@users.noreply.github.com>
Date: Tue, 21 May 2024 16:41:45 +1000
Subject: [PATCH] knownhosts hostname fix (#206)

---
 pkg/ssh/hostkey/callbacks.go | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/pkg/ssh/hostkey/callbacks.go b/pkg/ssh/hostkey/callbacks.go
index 689cb0b6..aa71c181 100644
--- a/pkg/ssh/hostkey/callbacks.go
+++ b/pkg/ssh/hostkey/callbacks.go
@@ -98,7 +98,15 @@ func wrapCallback(hkc ssh.HostKeyCallback, path string, permissive, hash bool) s
 			return fmt.Errorf("failed to open ssh known_hosts file %s for writing: %w", path, err)
 		}
 
-		knownHostsEntry := knownhosts.Normalize(remote.String())
+		knownHostsEntry := ""
+		if t, ok := remote.(*net.TCPAddr); ok && t.IP.IsUnspecified() {
+			// fallback to hostname if remote addr is unspecified
+			// see: https://github.com/k0sproject/k0sctl/issues/717
+			knownHostsEntry = knownhosts.Normalize(hostname)
+		} else {
+			knownHostsEntry = knownhosts.Normalize(remote.String())
+		}
+
 		if hash {
 			knownHostsEntry = knownhosts.HashHostname(knownHostsEntry)
 		}