Preserve kernel-range form for Vips remoteports

The previous commit on this branch accidentally changed the Vips path in
ResolveNFSTarget from "<startIP>-<endIP>" (kernel-range syntax that expands
to every IP in the range) to "<startIP>,<endIP>" (just two IPs, comma-joined).
That drops every IP between the endpoints and defeats the load-balancing the
range form was emitting.

The comma-joined form is correct for the new DNS-resolution output in
materializeNFSTarget (which produces a list of discrete IPs from
getaddrinfo). It is NOT correct for the Vips range, which is a 2-element
[startIP, endIP] contract documented at ExpectedVIPRangeLen.

Restore "<startIP>-<endIP>" for the 2-element case and "first-last" for the
defensive >2 case. Update tests to match.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: npujari-crusoe

internal/crusoe/disk.go

@@ -165,13 +165,16 @@ func CheckDiskMatchesRequest(disk *crusoeapi.DiskV1Alpha5,
 // authoritative VIP set from the storage API and bypasses OVN's DNS intercept,
 // which has produced ENOKEY, EPROTONOSUPPORT and the musl REFUSED failure
 // modes from INC-450 in production. When vips is populated we return the
-// full set joined by "," so the kernel's NFS client receives an explicit IP
-// list in remoteports= and never invokes the dns_resolver keyring upcall.
-// Only when vips is empty do we fall back to dns_name (which the caller will
-// resolve in-process before passing to mount).
+// kernel-range form "<startIP>-<endIP>" so remoteports= expands to every IP
+// in the range without invoking the dns_resolver keyring upcall. Only when
+// vips is empty do we fall back to dns_name (which the caller will resolve
+// in-process before passing to mount).
 //
-// Vips is contracted to be a 2-element [startIP, endIP] range; we tolerate
-// other lengths defensively but warn so the discrepancy is visible.
+// Vips is contracted to be a 2-element [startIP, endIP] range. We tolerate
+// other lengths defensively but warn so the discrepancy is visible. We do
+// NOT comma-join the range endpoints — comma-joining would yield only the
+// two endpoint IPs and drop every IP in between, defeating the load-balancing
+// the range is meant to provide.
 func ResolveNFSTarget(disk *crusoeapi.DiskV1Alpha5) (host, remotePorts string, ok bool) {
 	if len(disk.Vips) > 0 {
 		return resolveFromVIPs(disk)
@@ -183,25 +186,27 @@ func ResolveNFSTarget(disk *crusoeapi.DiskV1Alpha5) (host, remotePorts string, o
 	return "", "", false
 }
 
-// resolveFromVIPs builds an explicit IP-list remoteports string from a disk's
-// vips field. The first IP doubles as the mount-source host so busybox-mount
-// in the Alpine CSI pod never has to do its own getaddrinfo either.
+// resolveFromVIPs builds the kernel-range remoteports string ("startIP-endIP")
+// from a disk's vips field. The first IP doubles as the mount-source host so
+// busybox-mount in the Alpine CSI pod never has to do its own getaddrinfo
+// either. The hyphenated range form is parsed by the Linux NFS client and
+// expanded to every IP between start and end inclusive.
 func resolveFromVIPs(disk *crusoeapi.DiskV1Alpha5) (host, remotePorts string, ok bool) {
 	switch len(disk.Vips) {
 	case 0:
 		return "", "", false
 	case ExpectedVIPRangeLen:
-		return disk.Vips[0], strings.Join(disk.Vips, ","), true
+		return disk.Vips[0], fmt.Sprintf("%s-%s", disk.Vips[0], disk.Vips[1]), true
 	case 1:
 		klog.Warningf("disk %s returned %d vip(s), expected %d ([startIP, endIP]); using single vip %q",
 			disk.Id, len(disk.Vips), ExpectedVIPRangeLen, disk.Vips[0])
 
 		return disk.Vips[0], disk.Vips[0], true
 	default:
-		klog.Warningf("disk %s returned %d vips, expected %d ([startIP, endIP]); joining all into remoteports",
-			disk.Id, len(disk.Vips), ExpectedVIPRangeLen)
+		klog.Warningf("disk %s returned %d vips, expected %d ([startIP, endIP]); using first and last %q-%q",
+			disk.Id, len(disk.Vips), ExpectedVIPRangeLen, disk.Vips[0], disk.Vips[len(disk.Vips)-1])
 
-		return disk.Vips[0], strings.Join(disk.Vips, ","), true
+		return disk.Vips[0], fmt.Sprintf("%s-%s", disk.Vips[0], disk.Vips[len(disk.Vips)-1]), true
 	}
 }
 

internal/crusoe/disk_test.go

@@ -38,14 +38,14 @@ func TestResolveNFSTarget(t *testing.T) {
 				Vips:    []string{"1.2.3.4", "1.2.3.8"},
 			},
 			wantHost:        "1.2.3.4",
-			wantRemotePorts: "1.2.3.4,1.2.3.8",
+			wantRemotePorts: "1.2.3.4-1.2.3.8",
 			wantOK:          true,
 		},
 		{
-			name:            "vip range produces comma-joined remoteports",
+			name:            "vip range produces kernel-range remoteports",
 			disk:            crusoeapi.DiskV1Alpha5{Vips: []string{"1.2.3.4", "1.2.3.8"}},
 			wantHost:        "1.2.3.4",
-			wantRemotePorts: "1.2.3.4,1.2.3.8",
+			wantRemotePorts: "1.2.3.4-1.2.3.8",
 			wantOK:          true,
 		},
 		{
@@ -56,10 +56,10 @@ func TestResolveNFSTarget(t *testing.T) {
 			wantOK:          true,
 		},
 		{
-			name:            "more than two vips joins the entire list",
+			name:            "more than two vips uses first and last as range endpoints",
 			disk:            crusoeapi.DiskV1Alpha5{Vips: []string{"1.2.3.4", "1.2.3.5", "1.2.3.8"}},
 			wantHost:        "1.2.3.4",
-			wantRemotePorts: "1.2.3.4,1.2.3.5,1.2.3.8",
+			wantRemotePorts: "1.2.3.4-1.2.3.8",
 			wantOK:          true,
 		},
 	}