Support networking.k8s.io/v1beta1 Ingresses

Signed-off-by: Mikkel Oscar Lyderik Larsen <mikkel.larsen@zalando.de>

README.md

@@ -1,13 +1,10 @@
 # kube-metrics-adapter
 [![Build Status](https://travis-ci.org/zalando-incubator/kube-metrics-adapter.svg?branch=master)](https://travis-ci.org/zalando-incubator/kube-metrics-adapter)
 [![Coverage Status](https://coveralls.io/repos/github/zalando-incubator/kube-metrics-adapter/badge.svg?branch=master)](https://coveralls.io/github/zalando-incubator/kube-metrics-adapter?branch=master)
-
 Kube Metrics Adapter is a general purpose metrics adapter for Kubernetes that
 can collect and serve custom and external metrics for Horizontal Pod
 Autoscaling.
 
-It supports scaling based on [Prometheus metrics](https://prometheus.io/), [SQS queues](https://aws.amazon.com/sqs/) and others out of the box.
-
 It discovers Horizontal Pod Autoscaling resources and starts to collect the
 requested metrics and stores them in memory. It's implemented using the
 [custom-metrics-apiserver](https://github.com/kubernetes-incubator/custom-metrics-apiserver)
@@ -44,18 +41,6 @@ The `metric-config.*` annotations are used by the `kube-metrics-adapter` to
 configure a collector for getting the metrics. In the above example it
 configures a *json-path pod collector*.
 
-## Kubernetes compatibility
-
-Like the [support
-policy](https://kubernetes.io/docs/setup/release/version-skew-policy/) offered
-for Kubernetes, this project aims to support the latest three minor releases of
-Kubernetes.
-
-Currently the default supported API is `autoscaling/v2beta1`. However we aim to
-move to `autoscaling/v2beta2` (available since `v1.12`) in the near future as
-this adds a lot of improvements over `v2beta1`. The move to `v2beta2` will most
-likely happen as soon as [GKE adds support for it](https://issuetracker.google.com/issues/135624588).
-
 ## Building
 
 This project uses [Go modules](https://github.com/golang/go/wiki/Modules) as
@@ -86,9 +71,9 @@ Currently only `json-path` collection is supported.
 
 ### Supported metrics
 
-| Metric | Description | Type | K8s Versions |
+| Metric | Description | Type |
-| ------------ | -------------- | ------- | -- |
+| ------------ | -------------- | ------- |
-| *custom* | No predefined metrics. Metrics are generated from user defined queries. | Pods | `>=1.10` |
+| *custom* | No predefined metrics. Metrics are generated from user defined queries. | Pods |
 
 ### Example
 
@@ -106,7 +91,6 @@ metadata:
     metric-config.pods.requests-per-second.json-path/path: /metrics
     metric-config.pods.requests-per-second.json-path/port: "9090"
     metric-config.pods.requests-per-second.json-path/scheme: "https"
-    metric-config.pods.requests-per-second.json-path/aggregator: "max"
 spec:
   scaleTargetRef:
     apiVersion: apps/v1
@@ -144,11 +128,6 @@ The other configuration options `path`, `port` and `scheme` specify where the me
 endpoint is exposed on the pod. The `path` and `port` options do not have default values
 so they must be defined. The `scheme` is optional and defaults to `http`.
 
-The `aggregator` configuration option specifies the aggregation function used to aggregate
-values of JSONPath expressions that evaluate to arrays/slices of numbers.
-It's optional but when the expression evaluates to an array/slice, it's absence will
-produce an error. The supported aggregation functions are `avg`, `max`, `min` and `sum`.
-
 ## Prometheus collector
 
 The Prometheus collector is a generic collector which can map Prometheus
@@ -172,10 +151,10 @@ the trade-offs between the two approaches.
 
 ### Supported metrics
 
-| Metric | Description | Type | Kind | K8s Versions |
+| Metric | Description | Type | Kind |
-| ------------ | -------------- | ------- | -- | -- |
+| ------------ | -------------- | ------- | -- |
-| `prometheus-query` | Generic metric which requires a user defined query. | External | | `>=1.10` |
+| `prometheus-query` | Generic metric which requires a user defined query. | External | |
-| *custom* | No predefined metrics. Metrics are generated from user defined queries. | Object | *any* | `>=1.10` |
+| *custom* | No predefined metrics. Metrics are generated from user defined queries. | Object | *any* |
 
 ### Example: External Metric
 
@@ -280,9 +259,9 @@ box so users don't have to define those manually.
 
 ### Supported metrics
 
-| Metric | Description | Type | Kind | K8s Versions |
+| Metric | Description | Type | Kind |
-| ----------- | -------------- | ------ | ---- | ---- |
+| ----------- | -------------- | ------ | ---- |
-| `requests-per-second` | Scale based on requests per second for a certain ingress. | Object | `Ingress` | `>=1.14` (can work with `>=1.10`) |
+| `requests-per-second` | Scale based on requests per second for a certain ingress. | Object | `Ingress` |
 
 ### Example
 
@@ -309,10 +288,7 @@ spec:
         apiVersion: extensions/v1beta1
         kind: Ingress
         name: myapp
-      averageValue: 10 # Only works with Kubernetes >=1.14
+      targetValue: 10 # this will be treated as targetAverageValue
-      # for Kubernetes <1.14 you can use `targetValue` instead:
-      targetValue: 10 # this must be set, but has no effect if `averageValue` is defined.
-                      # Otherwise it will be treated as targetAverageValue
 ```
 
 ### Metric weighting based on backend
@@ -326,17 +302,13 @@ return the requests-per-second being sent to the `backend1`. The ingress annotat
 the backend weights can be obtained can be specified through the flag `--skipper-backends-annotation`.
 
 
-**Note:** For Kubernetes `<v1.14` the HPA does not support `averageValue` for
+**Note:** As of Kubernetes v1.10 the HPA does not support `targetAverageValue` for
 metrics of type `Object`. In case of requests per second it does not make sense
 to scale on a summed value because you can not make the total requests per
 second go down by adding more pods. For this reason the skipper collector will
 automatically treat the value you define in `targetValue` as an average per pod
 instead of a total sum.
 
-**ONLY use `targetValue` if you are on Kubernetes
-`<1.14`, it is not as percise as using `averageValue` and will not be supported
-after Kubernetes `v1.16` is released according to the [support policy](https://kubernetes.io/docs/setup/release/version-skew-policy/).**
-
 ## AWS collector
 
 The AWS collector allows scaling based on external metrics exposed by AWS
@@ -368,9 +340,9 @@ PolicyDocument:
 
 ### Supported metrics
 
-| Metric | Description | Type | K8s Versions |
+| Metric | Description | Type |
-| ------------ | ------- | -- | -- |
+| ------------ | ------- | -- |
-| `sqs-queue-length` | Scale based on SQS queue length | External | `>=1.10` |
+| `sqs-queue-length` | Scale based on SQS queue length | External |
 
 ### Example
 
@@ -416,9 +388,9 @@ The ZMON collector allows scaling based on external metrics exposed by
 
 ### Supported metrics
 
-| Metric | Description | Type | K8s Versions |
+| Metric | Description | Type |
-| ------------ | ------- | -- | -- |
+| ------------ | ------- | -- |
-| `zmon-check` | Scale based on any ZMON check results | External | `>=1.10` |
+| `zmon-check` | Scale based on any ZMON check results | External |
 
 ### Example
 

SECURITY.md

@@ -1,8 +1,7 @@
 We acknowledge that every line of code that we write may potentially contain security issues.
-We are trying to deal with it responsibly and provide patches as quickly as possible.
 
-We host our bug bounty program on HackerOne, it is currently private, therefore if you would like to report a vulnerability and get rewarded for it, please ask to join our program by filling this form:
+We are trying to deal with it responsibly and provide patches as quickly as  possible. If you have anything to report to us please use the following channels:
 
-https://corporate.zalando.com/en/services-and-contact#security-form
+Email: Tech-Security@zalando.de
-
+OR
-You can also send you report via this form if you do not want to join our bug bounty program and just want to report a vulnerability or security issue.
+Submit your vulnerability report through our bug bounty program at: https://hackerone.com/zalando

example/deploy/hpa.yaml

@@ -37,8 +37,7 @@ spec:
         apiVersion: extensions/v1beta1
         kind: Ingress
         name: custom-metrics-consumer
-      averageValue: 10
+      targetValue: 10 # this will be treated as targetAverageValue
-      targetValue: 10 # this must be set, but has no effect if `averageValue` is defined.
   - type: External
     external:
       metricName: sqs-queue-length

pkg/collector/collector.go

@@ -165,7 +165,6 @@ type MetricConfig struct {
 	ObjectReference custom_metrics.ObjectReference
 	PerReplica      bool
 	Interval        time.Duration
-	MetricSpec      autoscalingv2.MetricSpec
 }
 
 // ParseHPAMetrics parses the HPA object into a list of metric configurations.
@@ -207,15 +206,12 @@ func ParseHPAMetrics(hpa *autoscalingv2.HorizontalPodAutoscaler) ([]*MetricConfi
 			MetricTypeName:  typeName,
 			ObjectReference: ref,
 			Config:          map[string]string{},
-			MetricSpec:      metric,
 		}
 
 		if metric.Type == autoscalingv2.ExternalMetricSourceType &&
 			metric.External.Metric.Selector != nil &&
 			metric.External.Metric.Selector.MatchLabels != nil {
-			for k, v := range metric.External.Metric.Selector.MatchLabels {
+			config.Config = metric.External.Metric.Selector.MatchLabels
-				config.Config[k] = v
-			}
 		}
 
 		annotationConfigs, present := parser.GetAnnotationConfig(typeName.Metric.Name, typeName.Type)

pkg/collector/json_path_collector.go

@@ -4,7 +4,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
-	"math"
 	"net/http"
 	"net/url"
 	"strconv"
@@ -22,7 +21,6 @@ type JSONPathMetricsGetter struct {
 	scheme   string
 	path     string
 	port     int
-	aggregator string
 }
 
 // NewJSONPathMetricsGetter initializes a new JSONPathMetricsGetter.
@@ -30,12 +28,12 @@ func NewJSONPathMetricsGetter(config map[string]string) (*JSONPathMetricsGetter,
 	getter := &JSONPathMetricsGetter{}
 
 	if v, ok := config["json-key"]; ok {
-		path, err := jsonpath.Compile(v)
+		pat, err := jsonpath.Compile(v)
 		if err != nil {
 			return nil, fmt.Errorf("failed to parse json path definition: %v", err)
 		}
 
-		getter.jsonPath = path
+		getter.jsonPath = pat
 	}
 
 	if v, ok := config["scheme"]; ok {
@@ -54,10 +52,6 @@ func NewJSONPathMetricsGetter(config map[string]string) (*JSONPathMetricsGetter,
 		getter.port = n
 	}
 
-	if v, ok := config["aggregator"]; ok {
-		getter.aggregator = v
-	}
-
 	return getter, nil
 }
 
@@ -89,38 +83,11 @@ func (g *JSONPathMetricsGetter) GetMetric(pod *corev1.Pod) (float64, error) {
 		return float64(res), nil
 	case float64:
 		return res, nil
-	case []interface{}:
-		s, err := castSlice(res)
-		if err != nil {
-			return 0, err
-		}
-		return reduce(s, g.aggregator)
 	default:
 		return 0, fmt.Errorf("unsupported type %T", res)
 	}
 }
 
-// castSlice takes a slice of interface and returns a slice of float64 if all
-// values in slice were castable, else returns an error
-func castSlice(in []interface{}) ([]float64, error) {
-	out := []float64{}
-
-	for _, v := range in {
-		switch v := v.(type) {
-		case int:
-			out = append(out, float64(v))
-		case float32:
-			out = append(out, float64(v))
-		case float64:
-			out = append(out, v)
-		default:
-			return nil, fmt.Errorf("slice was returned by JSONPath, but value inside is unsupported: %T", v)
-		}
-	}
-
-	return out, nil
-}
-
 // getPodMetrics returns the content of the pods metrics endpoint.
 func getPodMetrics(pod *corev1.Pod, scheme, path string, port int) ([]byte, error) {
 	if pod.Status.PodIP == "" {
@@ -164,64 +131,3 @@ func getPodMetrics(pod *corev1.Pod, scheme, path string, port int) ([]byte, erro
 
 	return data, nil
 }
-
-// reduce will reduce a slice of numbers given a aggregator function's name. If it's empty or not recognized, an error is returned.
-func reduce(values []float64, aggregator string) (float64, error) {
-	switch aggregator {
-	case "avg":
-		return avg(values), nil
-	case "min":
-		return min(values), nil
-	case "max":
-		return max(values), nil
-	case "sum":
-		return sum(values), nil
-	default:
-		return 0, fmt.Errorf("slice of numbers was returned by JSONPath, but no valid aggregator function was specified: %v", aggregator)
-	}
-}
-
-// avg implements the average mathematical function over a slice of float64
-func avg(values []float64) float64 {
-	sum := sum(values)
-	return sum / float64(len(values))
-}
-
-// min implements the absolute minimum mathematical function over a slice of float64
-func min(values []float64) float64 {
-	// initialized with positive infinity, all finite numbers are smaller than it
-	curMin := math.Inf(1)
-
-	for _, v := range values {
-		if v < curMin {
-			curMin = v
-		}
-	}
-
-	return curMin
-}
-
-// max implements the absolute maximum mathematical function over a slice of float64
-func max(values []float64) float64 {
-	// initialized with negative infinity, all finite numbers are bigger than it
-	curMax := math.Inf(-1)
-
-	for _, v := range values {
-		if v > curMax {
-			curMax = v
-		}
-	}
-
-	return curMax
-}
-
-// sum implements the summation mathematical function over a slice of float64
-func sum(values []float64) float64 {
-	res := 0.0
-
-	for _, v := range values {
-		res += v
-	}
-
-	return res
-}

pkg/collector/json_path_collector_test.go

@@ -1,105 +0,0 @@
-package collector
-
-import (
-	"testing"
-
-	"github.com/oliveagle/jsonpath"
-	"github.com/stretchr/testify/require"
-)
-
-func TestNewJSONPathMetricsGetter(t *testing.T) {
-	configNoAggregator := map[string]string{
-		"json-key": "$.value",
-		"scheme":   "http",
-		"path":     "/metrics",
-		"port":     "9090",
-	}
-	jpath1, _ := jsonpath.Compile(configNoAggregator["json-key"])
-	getterNoAggregator, err1 := NewJSONPathMetricsGetter(configNoAggregator)
-
-	require.NoError(t, err1)
-	require.Equal(t, &JSONPathMetricsGetter{
-		jsonPath: jpath1,
-		scheme:   "http",
-		path:     "/metrics",
-		port:     9090,
-	}, getterNoAggregator)
-
-	configAggregator := map[string]string{
-		"json-key":   "$.values",
-		"scheme":     "http",
-		"path":       "/metrics",
-		"port":       "9090",
-		"aggregator": "avg",
-	}
-	jpath2, _ := jsonpath.Compile(configAggregator["json-key"])
-	getterAggregator, err2 := NewJSONPathMetricsGetter(configAggregator)
-
-	require.NoError(t, err2)
-	require.Equal(t, &JSONPathMetricsGetter{
-		jsonPath:   jpath2,
-		scheme:     "http",
-		path:       "/metrics",
-		port:       9090,
-		aggregator: "avg",
-	}, getterAggregator)
-
-	configErrorJSONPath := map[string]string{
-		"json-key": "{}",
-		"scheme":   "http",
-		"path":     "/metrics",
-		"port":     "9090",
-	}
-
-	_, err3 := NewJSONPathMetricsGetter(configErrorJSONPath)
-	require.Error(t, err3)
-
-	configErrorPort := map[string]string{
-		"json-key": "$.values",
-		"scheme":   "http",
-		"path":     "/metrics",
-		"port":     "a9090",
-	}
-
-	_, err4 := NewJSONPathMetricsGetter(configErrorPort)
-	require.Error(t, err4)
-}
-
-func TestCastSlice(t *testing.T) {
-	res1, err1 := castSlice([]interface{}{1, 2, 3})
-	require.NoError(t, err1)
-	require.Equal(t, []float64{1.0, 2.0, 3.0}, res1)
-
-	res2, err2 := castSlice([]interface{}{float32(1.0), float32(2.0), float32(3.0)})
-	require.NoError(t, err2)
-	require.Equal(t, []float64{1.0, 2.0, 3.0}, res2)
-
-	res3, err3 := castSlice([]interface{}{float64(1.0), float64(2.0), float64(3.0)})
-	require.NoError(t, err3)
-	require.Equal(t, []float64{1.0, 2.0, 3.0}, res3)
-
-	res4, err4 := castSlice([]interface{}{1, 2, "some string"})
-	require.Errorf(t, err4, "slice was returned by JSONPath, but value inside is unsupported: %T", "string")
-	require.Equal(t, []float64(nil), res4)
-}
-
-func TestReduce(t *testing.T) {
-	average, err1 := reduce([]float64{1, 2, 3}, "avg")
-	require.NoError(t, err1)
-	require.Equal(t, 2.0, average)
-
-	min, err2 := reduce([]float64{1, 2, 3}, "min")
-	require.NoError(t, err2)
-	require.Equal(t, 1.0, min)
-
-	max, err3 := reduce([]float64{1, 2, 3}, "max")
-	require.NoError(t, err3)
-	require.Equal(t, 3.0, max)
-
-	sum, err4 := reduce([]float64{1, 2, 3}, "sum")
-	require.NoError(t, err4)
-	require.Equal(t, 6.0, sum)
-
-	_, err5 := reduce([]float64{1, 2, 3}, "inexistent_function")
-	require.Errorf(t, err5, "slice of numbers was returned by JSONPath, but no valid aggregator function was specified: %v", "inexistent_function")
-}

pkg/collector/max_collector.go

@@ -0,0 +1,67 @@
+package collector
+
+import (
+	"fmt"
+	"strings"
+	"time"
+
+	"k8s.io/apimachinery/pkg/api/resource"
+)
+
+// MaxWeightedCollector is a simple aggregator collector that returns the maximum value
+// of metrics from all collectors.
+type MaxWeightedCollector struct {
+	collectors []Collector
+	interval   time.Duration
+	weight     float64
+}
+
+// NewMaxWeightedCollector initializes a new MaxWeightedCollector.
+func NewMaxWeightedCollector(interval time.Duration, weight float64, collectors ...Collector) *MaxWeightedCollector {
+	return &MaxWeightedCollector{
+		collectors: collectors,
+		interval:   interval,
+		weight:     weight,
+	}
+}
+
+// GetMetrics gets metrics from all collectors and return the higest value.
+func (c *MaxWeightedCollector) GetMetrics() ([]CollectedMetric, error) {
+	errors := make([]error, 0)
+	collectedMetrics := make([]CollectedMetric, 0)
+	for _, collector := range c.collectors {
+		values, err := collector.GetMetrics()
+		if err != nil {
+			if _, ok := err.(NoResultError); ok {
+				errors = append(errors, err)
+				continue
+			}
+			return nil, err
+		}
+		collectedMetrics = append(collectedMetrics, values...)
+	}
+	if len(collectedMetrics) == 0 {
+		if len(errors) == 0 {
+			return nil, fmt.Errorf("no metrics collected, cannot determine max")
+		}
+		errorStrings := make([]string, len(errors))
+		for i, e := range errors {
+			errorStrings[i] = e.Error()
+		}
+		allErrors := strings.Join(errorStrings, ",")
+		return nil, fmt.Errorf("could not determine maximum due to errors: %s", allErrors)
+	}
+	max := collectedMetrics[0]
+	for _, value := range collectedMetrics {
+		if value.Custom.Value.MilliValue() > max.Custom.Value.MilliValue() {
+			max = value
+		}
+	}
+	max.Custom.Value = *resource.NewMilliQuantity(int64(c.weight*float64(max.Custom.Value.MilliValue())), resource.DecimalSI)
+	return []CollectedMetric{max}, nil
+}
+
+// Interval returns the interval at which the collector should run.
+func (c *MaxWeightedCollector) Interval() time.Duration {
+	return c.interval
+}

pkg/collector/max_collector_test.go

@@ -0,0 +1,99 @@
+package collector
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+	"k8s.io/apimachinery/pkg/api/resource"
+	"k8s.io/metrics/pkg/apis/custom_metrics"
+)
+
+type dummyCollector struct {
+	value int64
+}
+
+func (c dummyCollector) Interval() time.Duration {
+	return time.Second
+}
+
+func (c dummyCollector) GetMetrics() ([]CollectedMetric, error) {
+	switch c.value {
+	case 0:
+		return nil, NoResultError{query: "invalid query"}
+	case -1:
+		return nil, fmt.Errorf("test error")
+	default:
+		quantity := resource.NewQuantity(c.value, resource.DecimalSI)
+		return []CollectedMetric{
+			{
+				Custom: custom_metrics.MetricValue{
+					Value: *quantity,
+				},
+			},
+		}, nil
+	}
+}
+
+func TestMaxCollector(t *testing.T) {
+	for _, tc := range []struct {
+		name     string
+		values   []int64
+		expected int
+		weight   float64
+		errored  bool
+	}{
+		{
+			name:     "basic",
+			values:   []int64{100, 10, 9},
+			expected: 100,
+			weight:   1,
+			errored:  false,
+		},
+		{
+			name:     "weighted",
+			values:   []int64{100, 10, 9},
+			expected: 20,
+			weight:   0.2,
+			errored:  false,
+		},
+		{
+			name:    "with error",
+			values:  []int64{10, 9, -1},
+			weight:  0.5,
+			errored: true,
+		},
+		{
+			name:     "some invalid results",
+			values:   []int64{0, 1, 0, 10, 9},
+			expected: 5,
+			weight:   0.5,
+			errored:  false,
+		},
+		{
+			name:    "both invalid results and errors",
+			values:  []int64{0, 1, 0, -1, 10, 9},
+			weight:  0.5,
+			errored: true,
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			collectors := make([]Collector, len(tc.values))
+			for i, v := range tc.values {
+				collectors[i] = dummyCollector{value: v}
+			}
+			wc := NewMaxWeightedCollector(time.Second, tc.weight, collectors...)
+			metrics, err := wc.GetMetrics()
+			if tc.errored {
+				require.Error(t, err)
+			} else {
+				require.NoError(t, err)
+				require.Len(t, metrics, 1)
+				require.EqualValues(t, tc.expected, metrics[0].Custom.Value.Value())
+			}
+
+		})
+
+	}
+}

pkg/collector/prometheus_collector.go

@@ -3,7 +3,6 @@ package collector
 import (
 	"context"
 	"fmt"
-	"math"
 	"net/http"
 	"time"
 
@@ -147,7 +146,7 @@ func (c *PrometheusCollector) GetMetrics() ([]CollectedMetric, error) {
 		sampleValue = scalar.Value
 	}
 
-	if math.IsNaN(float64(sampleValue)) {
+	if sampleValue.String() == "NaN" {
 		return nil, &NoResultError{query: c.query}
 	}
 

pkg/collector/skipper_collector.go

@@ -5,7 +5,6 @@ import (
 	"errors"
 	"fmt"
 	"math"
-	"regexp"
 	"strings"
 	"time"
 
@@ -17,7 +16,7 @@ import (
 )
 
 const (
-	rpsQuery                  = `scalar(sum(rate(skipper_serve_host_duration_seconds_count{host=~"%s"}[1m])) * %.4f)`
+	rpsQuery                  = `scalar(sum(rate(skipper_serve_host_duration_seconds_count{host="%s"}[1m])))`
 	rpsMetricName             = "requests-per-second"
 	rpsMetricBackendSeparator = ","
 )
@@ -73,7 +72,8 @@ type SkipperCollector struct {
 }
 
 // NewSkipperCollector initializes a new SkipperCollector.
-func NewSkipperCollector(client kubernetes.Interface, plugin CollectorPlugin, hpa *autoscalingv2.HorizontalPodAutoscaler, config *MetricConfig, interval time.Duration, backendAnnotations []string, backend string) (*SkipperCollector, error) {
+func NewSkipperCollector(client kubernetes.Interface, plugin CollectorPlugin, hpa *autoscalingv2.HorizontalPodAutoscaler,
+	config *MetricConfig, interval time.Duration, backendAnnotations []string, backend string) (*SkipperCollector, error) {
 	return &SkipperCollector{
 		client:             client,
 		objectReference:    config.ObjectReference,
@@ -125,28 +125,42 @@ func getWeights(ingressAnnotations map[string]string, backendAnnotations []strin
 
 // getCollector returns a collector for getting the metrics.
 func (c *SkipperCollector) getCollector() (Collector, error) {
+	var annotations map[string]string
+	var hosts []string
+
+	switch c.objectReference.APIVersion {
+	case "extensions/v1beta1":
 		ingress, err := c.client.ExtensionsV1beta1().Ingresses(c.objectReference.Namespace).Get(c.objectReference.Name, metav1.GetOptions{})
 		if err != nil {
 			return nil, err
 		}
+		annotations = ingress.Annotations
+		for _, rule := range ingress.Spec.Rules {
+			hosts = append(hosts, rule.Host)
+		}
+	case "networking.k8s.io/v1beta1":
+		ingress, err := c.client.NetworkingV1beta1().Ingresses(c.objectReference.Namespace).Get(c.objectReference.Name, metav1.GetOptions{})
+		if err != nil {
+			return nil, err
+		}
+		annotations = ingress.Annotations
+		for _, rule := range ingress.Spec.Rules {
+			hosts = append(hosts, rule.Host)
+		}
+	}
 
-	backendWeight, err := getWeights(ingress.Annotations, c.backendAnnotations, c.backend)
+	backendWeight, err := getWeights(annotations, c.backendAnnotations, c.backend)
 	if err != nil {
 		return nil, err
 	}
 	config := c.config
 
-	var escapedHostnames []string
+	var collector Collector
-	for _, rule := range ingress.Spec.Rules {
+	collectors := make([]Collector, 0, len(hosts))
-		escapedHostnames = append(escapedHostnames, regexp.QuoteMeta(strings.Replace(rule.Host, ".", "_", -1)))
+	for _, host := range hosts {
-	}
+		host := strings.Replace(host, ".", "_", -1)
-
-	if len(escapedHostnames) == 0 {
-		return nil, fmt.Errorf("no hosts defined on ingress %s/%s, unable to create collector", c.objectReference.Namespace, c.objectReference.Name)
-	}
-
 		config.Config = map[string]string{
-		"query": fmt.Sprintf(rpsQuery, strings.Join(escapedHostnames, "|"), backendWeight),
+			"query": fmt.Sprintf(rpsQuery, host),
 		}
 
 		config.PerReplica = false // per replica is handled outside of the prometheus collector
@@ -155,6 +169,15 @@ func (c *SkipperCollector) getCollector() (Collector, error) {
 			return nil, err
 		}
 
+		collectors = append(collectors, collector)
+	}
+
+	if len(collectors) > 0 {
+		collector = NewMaxWeightedCollector(c.interval, backendWeight, collectors...)
+	} else {
+		return nil, fmt.Errorf("no hosts defined on ingress %s/%s, unable to create collector", c.objectReference.Namespace, c.objectReference.Name)
+	}
+
 	return collector, nil
 }
 
@@ -174,10 +197,6 @@ func (c *SkipperCollector) GetMetrics() ([]CollectedMetric, error) {
 		return nil, fmt.Errorf("expected to only get one metric value, got %d", len(values))
 	}
 
-	value := values[0]
-
-	// For Kubernetes <v1.14 we have to fall back to manual average
-	if c.config.MetricSpec.Object.Target.AverageValue == nil {
 	// get current replicas for the targeted scale object. This is used to
 	// calculate an average metric instead of total.
 	// targetAverageValue will be available in Kubernetes v1.12
@@ -191,9 +210,9 @@ func (c *SkipperCollector) GetMetrics() ([]CollectedMetric, error) {
 		return nil, fmt.Errorf("unable to get average value for %d replicas", replicas)
 	}
 
+	value := values[0]
 	avgValue := float64(value.Custom.Value.MilliValue()) / float64(replicas)
 	value.Custom.Value = *resource.NewMilliQuantity(int64(avgValue), resource.DecimalSI)
-	}
 
 	return []CollectedMetric{value}, nil
 }