[fix] Don't ignore --max-binpacking-time flag

Author: x13n

cluster-autoscaler/processors/binpacking/time_limiter.go

@@ -29,18 +29,27 @@ import (
 type TimeLimiter struct {
 	startTime             time.Time
 	maxBinpackingDuration time.Duration
+	now                   func() time.Time
 }
 
 // NewTimeLimiter returns an instance of a new TimeLimiter.
 func NewTimeLimiter(maxBinpackingDuration time.Duration) *TimeLimiter {
 	return &TimeLimiter{
 		maxBinpackingDuration: maxBinpackingDuration,
+		now:                   time.Now,
+	}
+}
+
+func newTimeLimiterWithClock(maxBinpackingDuration time.Duration, now func() time.Time) *TimeLimiter {
+	return &TimeLimiter{
+		maxBinpackingDuration: maxBinpackingDuration,
+		now:                   now,
 	}
 }
 
 // InitBinpacking initialises the TimeLimiter.
 func (b *TimeLimiter) InitBinpacking(autoscalingCtx *ca_context.AutoscalingContext, nodeGroups []cloudprovider.NodeGroup) {
-	b.startTime = time.Now()
+	b.startTime = b.now()
 }
 
 // MarkProcessed marks the nodegroup as processed.
@@ -49,9 +58,10 @@ func (b *TimeLimiter) MarkProcessed(autoscalingCtx *ca_context.AutoscalingContex
 
 // StopBinpacking returns true if the binpacking time exceeds maxBinpackingDuration.
 func (b *TimeLimiter) StopBinpacking(autoscalingCtx *ca_context.AutoscalingContext, evaluatedOptions []expander.Option) bool {
-	now := time.Now()
+	now := b.now()
 	if now.After(b.startTime.Add(b.maxBinpackingDuration)) {
 		klog.Infof("Binpacking is cut short after %v seconds due to exceeding maxBinpackingDuration", now.Sub(b.startTime).Seconds())
+		return true
 	}
 	return false
 }

cluster-autoscaler/processors/binpacking/time_limiter_test.go

@@ -0,0 +1,71 @@
+/*
+Copyright 2025 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package binpacking
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	testingclock "k8s.io/utils/clock/testing"
+)
+
+func TestTimeLimiter(t *testing.T) {
+	testCases := []struct {
+		name                  string
+		maxBinpackingDuration time.Duration
+		timeAdvanced          time.Duration
+		expectStop            bool
+	}{
+		{
+			name:                  "Time limit not exceeded",
+			maxBinpackingDuration: 10 * time.Second,
+			timeAdvanced:          5 * time.Second,
+			expectStop:            false,
+		},
+		{
+			name:                  "Time limit exceeded",
+			maxBinpackingDuration: 10 * time.Second,
+			timeAdvanced:          15 * time.Second,
+			expectStop:            true,
+		},
+		{
+			name:                  "Time limit met exactly",
+			maxBinpackingDuration: 10 * time.Second,
+			timeAdvanced:          10 * time.Second,
+			expectStop:            false,
+		},
+		{
+			name:                  "Zero duration",
+			maxBinpackingDuration: 0,
+			timeAdvanced:          1 * time.Millisecond,
+			expectStop:            true,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			fakeClock := testingclock.NewFakeClock(time.Now())
+			limiter := newTimeLimiterWithClock(tc.maxBinpackingDuration, fakeClock.Now)
+
+			limiter.InitBinpacking(nil, nil)
+			fakeClock.Step(tc.timeAdvanced)
+
+			assert.Equal(t, tc.expectStop, limiter.StopBinpacking(nil, nil))
+		})
+	}
+}