extractor_test.go

/*
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 metrics

import (
	"context"
	"testing"

	"github.com/google/go-cmp/cmp"
	dto "github.com/prometheus/client_model/go"
	"google.golang.org/protobuf/proto"
	"k8s.io/utils/ptr"

	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/datalayer"
)

const (
	// use hardcoded values - importing causes cycle
	defaultTotalQueuedRequestsMetric    = "vllm:num_requests_waiting"
	defaultTotalRunningRequestsMetric   = "vllm:num_requests_running"
	defaultKvCacheUsagePercentageMetric = "vllm:gpu_cache_usage_perc"
	defaultLoraInfoMetric               = "vllm:lora_requests_info"
	defaultCacheInfoMetric              = "vllm:cache_config_info"
)

func TestExtractorExtract(t *testing.T) {
	ctx := context.Background()

	if _, err := NewExtractor("vllm: dummy", "", "", "", ""); err == nil {
		t.Error("expected to fail to create extractor with invalid specification")
	}

	extractor, err := NewExtractor(defaultTotalQueuedRequestsMetric, defaultTotalRunningRequestsMetric,
		defaultKvCacheUsagePercentageMetric, defaultLoraInfoMetric, defaultCacheInfoMetric)
	if err != nil {
		t.Fatalf("failed to create extractor: %v", err)
	}

	if exType := extractor.TypedName().Type; exType == "" {
		t.Error("empty extractor type")
	}

	if inputType := extractor.ExpectedInputType(); inputType != PrometheusMetricType {
		t.Errorf("incorrect expected input type: %v", inputType)
	}

	ep := datalayer.NewEndpoint(nil, nil)
	if ep == nil {
		t.Fatal("expected non-nil endpoint")
	}

	tests := []struct {
		name    string
		data    any
		wantErr bool
		updated bool // whether metrics are expected to change
	}{
		{
			name:    "nil data",
			data:    nil,
			wantErr: true,
			updated: false,
		},
		{
			name:    "empty PrometheusMetricMap",
			data:    PrometheusMetricMap{},
			wantErr: true,  // errors when metrics are missing
			updated: false, // and also not updated...
		},
		{
			name: "single valid metric",
			data: PrometheusMetricMap{
				defaultTotalQueuedRequestsMetric: &dto.MetricFamily{
					Type: dto.MetricType_GAUGE.Enum(),
					Metric: []*dto.Metric{
						{
							Gauge: &dto.Gauge{Value: ptr.To(5.0)},
						},
					},
				},
			},
			wantErr: true, // missing metrics can return an error
			updated: true, // but should still update
		},
		{
			name: "multiple valid metrics",
			data: PrometheusMetricMap{
				defaultTotalQueuedRequestsMetric: &dto.MetricFamily{
					Type: dto.MetricType_GAUGE.Enum(),
					Metric: []*dto.Metric{
						{
							Gauge: &dto.Gauge{Value: ptr.To(5.0)},
						},
					},
				},
				defaultTotalRunningRequestsMetric: &dto.MetricFamily{
					Type: dto.MetricType_GAUGE.Enum(),
					Metric: []*dto.Metric{
						{
							Gauge: &dto.Gauge{Value: ptr.To(1.0)},
						},
					},
				},
				defaultKvCacheUsagePercentageMetric: &dto.MetricFamily{
					Type: dto.MetricType_GAUGE.Enum(),
					Metric: []*dto.Metric{
						{
							Gauge: &dto.Gauge{Value: ptr.To(0.5)},
						},
					},
				},
				defaultLoraInfoMetric: &dto.MetricFamily{
					Type: dto.MetricType_GAUGE.Enum(),
					Metric: []*dto.Metric{
						{
							Label: []*dto.LabelPair{
								{
									Name:  proto.String(LoraInfoRunningAdaptersMetricName),
									Value: proto.String("lora1"),
								},
								{
									Name:  proto.String(LoraInfoWaitingAdaptersMetricName),
									Value: proto.String("lora2"),
								},
								{
									Name:  proto.String(LoraInfoMaxAdaptersMetricName),
									Value: proto.String("1"),
								},
							},
						},
					},
				},
				defaultCacheInfoMetric: &dto.MetricFamily{
					Type: dto.MetricType_GAUGE.Enum(),
					Metric: []*dto.Metric{
						{
							Label: []*dto.LabelPair{
								{
									Name:  proto.String(CacheConfigBlockSizeInfoMetricName),
									Value: proto.String("16"),
								},
								{
									Name:  proto.String(CacheConfigNumGPUBlocksMetricName),
									Value: proto.String("1024"),
								},
							},
							Gauge: &dto.Gauge{Value: ptr.To(1.0)},
						},
					},
				},
			},
			wantErr: false,
			updated: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			defer func() {
				if r := recover(); r != nil {
					t.Errorf("Extract panicked: %v", r)
				}
			}()

			before := ep.GetMetrics().Clone()
			err := extractor.Extract(ctx, tt.data, ep)
			after := ep.GetMetrics()

			if tt.wantErr && err == nil {
				t.Errorf("expected error but got nil")
			}
			if !tt.wantErr && err != nil {
				t.Errorf("unexpected error: %v", err)
			}

			if tt.updated {
				if diff := cmp.Diff(before, after); diff == "" {
					t.Errorf("expected metrics to be updated, but no change detected")
				}
			} else {
				if diff := cmp.Diff(before, after); diff != "" {
					t.Errorf("expected no metrics update, but got changes:\n%s", diff)
				}
			}
		})
	}
}