fix(gpu): keep template device names and marks within API limits

A VMI name can be a 253-character DNS subdomain, and worker VMIs
named after Cluster API machines do grow long. Carried as a label
value it fails the 63-character limit, and with a suffix appended it
fails the name limit, so the webhook could not create the template
device at all. The mark is now a plain "true", and a name too long
for the suffix is shortened with a hash of the full VMI name.

The device-reference parser also refused nothing after the JSON list,
so a malformed annotation could pass as valid.

Fixes: a11737a2dd ("feat(gpu): fix the shared GPU keys, settings and binding contract")

Assisted-by: LLM
Signed-off-by: Aleksei Sviridkin <f@lex.la>

internal/gpu/config.go

@@ -31,6 +31,8 @@ type Config struct {
 	// set adds class and agent-reported names (model.ResourceNames).
 	ResourceNames []string
 
+	// RawResourceNames is the hoster's gpu.rawResourceNames; empty means
+	// RawNamesAllowed.
 	RawResourceNames RawNamesPolicy
 
 	// LostCapacityGrace is how long a device stays missing or unhealthy, or

internal/gpu/consts.go

@@ -31,8 +31,10 @@ const (
 	// to a VMI, so a reinvocation recognises its own entries.
 	VMIGPUNamePrefix = "gpudev-"
 
-	// LabelTemplateDevice marks a GPUDevice the webhook created from a
-	// deviceTemplate entry. Its value is the VMI name. Tenants cannot set it.
+	// LabelTemplateDevice, valued LabelValueTrue, marks a GPUDevice the
+	// webhook created from a deviceTemplate entry. Tenants cannot set it. The
+	// VMI is found through model.TemplateDeviceName, not the label, since a
+	// VMI name can exceed a label value's 63 characters.
 	LabelTemplateDevice = Group + "/template-device"
 
 	// LabelUsageMonitor is the reserved selector key of the controller-owned

internal/gpu/controller/setup_test.go

@@ -22,8 +22,8 @@ import (
 	"github.com/cozystack/cozystack/internal/gpu"
 )
 
-// Setup is wired into cozystack-controller before any reconciler exists:
-// it must succeed and touch nothing, so it accepts a nil manager.
+// Setup may be called before any reconciler exists: it must succeed and
+// touch nothing, so it accepts a nil manager.
 func TestSetupWithoutReconcilersIsANoOp(t *testing.T) {
 	if err := Setup(nil, gpu.Config{Enabled: true}); err != nil {
 		t.Fatalf("Setup: %v", err)

internal/gpu/doc.go

@@ -38,6 +38,10 @@ limitations under the License.
 //     with a Result, and admits the VMI only if all of them are Succeeded
 //     and share one node.
 //
+// model.Snapshot.CheckOrder judges one order. To judge a set, such as a
+// VMI's template devices, add each admitted device to the snapshot as Bound
+// before checking the next.
+//
 // The binder, for a request whose devices all carry the same ID, either
 // places the whole set on one eligible node with room for all of it, moving
 // or binding devices as needed, and writes Result Succeeded on each; or

internal/gpu/model/refs.go

@@ -18,10 +18,15 @@ package model
 
 import (
 	"bytes"
+	"crypto/sha256"
+	"encoding/hex"
 	"encoding/json"
 	"errors"
 	"fmt"
 	"strconv"
+	"strings"
+
+	"k8s.io/apimachinery/pkg/util/validation"
 )
 
 // DeviceRef is one entry of the gpu.AnnotationDevices list on a VMI:
@@ -47,6 +52,9 @@ func ParseDeviceRefs(s string) ([]DeviceRef, error) {
 	if err := dec.Decode(&refs); err != nil {
 		return nil, fmt.Errorf("parse device references: %w", err)
 	}
+	if dec.More() {
+		return nil, errors.New("parse device references: data after the list")
+	}
 	if len(refs) == 0 {
 		return nil, errors.New("device references: empty list")
 	}
@@ -80,7 +88,15 @@ func FormatDeviceRefs(refs []DeviceRef) (string, error) {
 
 // TemplateDeviceName names the GPUDevice created for the deviceTemplate
 // entry at index of a VMI's references, so a repeated admission or a
-// recreated VMI finds the same device.
+// recreated VMI finds the same device. A VMI name too long to take the
+// suffix is shortened and made unique by a hash of the full name.
 func TemplateDeviceName(vmi string, index int) string {
-	return vmi + "-gpu-" + strconv.Itoa(index)
+	suffix := "-gpu-" + strconv.Itoa(index)
+	if len(vmi)+len(suffix) <= validation.DNS1123SubdomainMaxLength {
+		return vmi + suffix
+	}
+	sum := sha256.Sum256([]byte(vmi))
+	hash := hex.EncodeToString(sum[:])[:10]
+	keep := validation.DNS1123SubdomainMaxLength - len(suffix) - len(hash) - 1
+	return strings.TrimRight(vmi[:keep], "-.") + "-" + hash + suffix
 }

internal/gpu/model/refs_test.go

@@ -18,7 +18,10 @@ package model
 
 import (
 	"reflect"
+	"strings"
 	"testing"
+
+	"k8s.io/apimachinery/pkg/util/validation"
 )
 
 func TestParseDeviceRefs(t *testing.T) {
@@ -41,6 +44,7 @@ func TestParseDeviceRefs(t *testing.T) {
 		{name: "template without class", in: `[{"deviceTemplate":{"count":1}}]`, wantErr: true},
 		{name: "unknown field", in: `[{"name":"nvidia.com/gpu"}]`, wantErr: true},
 		{name: "same device twice", in: `[{"device":"a"},{"device":"a"}]`, wantErr: true},
+		{name: "data after the list", in: `[{"device":"a"}] x`, wantErr: true},
 	}
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
@@ -71,4 +75,23 @@ func TestTemplateDeviceName(t *testing.T) {
 	if got := TemplateDeviceName("vm-instance-trainer", 1); got != "vm-instance-trainer-gpu-1" {
 		t.Errorf("TemplateDeviceName = %q", got)
 	}
+	// Worker VMIs are named after Cluster API machines and can reach the
+	// 253 characters of a DNS subdomain.
+	long := strings.Repeat("a", 120) + "." + strings.Repeat("b", 132)
+	other := strings.Repeat("a", 120) + "." + strings.Repeat("b", 131) + "c"
+	for _, vmi := range []string{long, other, strings.Repeat("x", 245) + "-" + "yyyyyyy"} {
+		got := TemplateDeviceName(vmi, 12)
+		if errs := validation.IsDNS1123Subdomain(got); len(errs) > 0 {
+			t.Errorf("TemplateDeviceName(%d chars) = %q: %v", len(vmi), got, errs)
+		}
+		if !strings.HasSuffix(got, "-gpu-12") {
+			t.Errorf("TemplateDeviceName lost the index: %q", got)
+		}
+	}
+	if TemplateDeviceName(long, 0) == TemplateDeviceName(other, 0) {
+		t.Error("two long VMI names sharing a prefix map to one device")
+	}
+	if TemplateDeviceName(long, 0) != TemplateDeviceName(long, 0) {
+		t.Error("TemplateDeviceName is not deterministic")
+	}
 }

internal/gpu/webhook/register_test.go

@@ -22,8 +22,8 @@ import (
 	"github.com/cozystack/cozystack/internal/gpu"
 )
 
-// Register is wired into cozystack-controller before any webhook exists:
-// it must succeed and touch nothing, so it accepts a nil manager.
+// Register may be called before any webhook exists: it must succeed and
+// touch nothing, so it accepts a nil manager.
 func TestRegisterWithoutWebhooksIsANoOp(t *testing.T) {
 	if err := Register(nil, gpu.Config{Enabled: true}); err != nil {
 		t.Fatalf("Register: %v", err)