Fix handling of invalid/empty json response (#209)

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

.github/CODEOWNERS

@@ -1,35 +0,0 @@
-# These owners will be the default owners for everything in
-# the repo. 
-*       @arjunrn
-
-
-
-# Samples for assigning codeowners below:
-# Order is important; the last matching pattern takes the most
-# precedence. When someone opens a pull request that only
-# modifies JS files, only @js-owner and not the global
-# owner(s) will be requested for a review.
-# *.js    @js-owner
-
-# You can also use email addresses if you prefer. They'll be
-# used to look up users just like we do for commit author
-# emails.
-# *.go docs@example.com
-
-# In this example, @doctocat owns any files in the build/logs
-# directory at the root of the repository and any of its
-# subdirectories.
-# /build/logs/ @doctocat
-
-# The `docs/*` pattern will match files like
-# `docs/getting-started.md` but not further nested files like
-# `docs/build-app/troubleshooting.md`.
-# docs/*  docs@example.com
-
-# In this example, @octocat owns any file in an apps directory
-# anywhere in your repository.
-# apps/ @octocat
-
-# In this example, @doctocat owns any file in the `/docs`
-# directory in the root of your repository.
-# /docs/ @doctocat

.github/dependabot.yml

@@ -0,0 +1,14 @@
+version: 2
+updates:
+- package-ecosystem: gomod
+  directory: "/"
+  schedule:
+    interval: monthly
+    time: "07:00"
+  open-pull-requests-limit: 10
+- package-ecosystem: docker
+  directory: "/"
+  schedule:
+    interval: monthly
+    time: "07:00"
+  open-pull-requests-limit: 10

.golangci.yml

@@ -1,7 +1,4 @@
 run:
-  skip-files:
-  - "pkg/provider/generated.conversion.go"
-  - "pkg/provider/conversion.go"
 linters-settings:
   golint:
       min-confidence: 0.9

.travis.yml

@@ -2,10 +2,10 @@ language: go
 dist: xenial
 
 go:
-  - "1.13.x"
+  - "1.14.x"
 
 env:
-- GO111MODULE=on GOLANGCI_RELEASE="v1.16.0"
+- GO111MODULE=on GOLANGCI_RELEASE="v1.21.0"
 
 before_install:
   - GO111MODULE=off go get github.com/mattn/goveralls
@@ -13,8 +13,8 @@ before_install:
   - curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | sh -s -- -b $(go env GOPATH)/bin ${GOLANGCI_RELEASE}
 
 script:
-  - make check
   - make test
   - make build.docker
+  - make check
   - roveralls
   - goveralls -v -coverprofile=roveralls.coverprofile -service=travis-ci

MAINTAINERS

@@ -1,3 +1,2 @@
 Mikkel Larsen <mikkel.larsen@zalando.de>
-Arjun Naik <arjun.naik@zalando.de>
 Team Teapot <team-teapot@zalando.de>

Makefile

@@ -19,7 +19,8 @@ test:
 	go test -v $(GOPKGS)
 
 check:
-	golangci-lint run ./...
+	go mod download
+	golangci-lint run --timeout=2m ./...
 
 build.local: build/$(BINARY)
 build.linux: build/linux/$(BINARY)

example/deploy/hpa.yaml

@@ -1,4 +1,4 @@
-apiVersion: autoscaling/v2beta1
+apiVersion: autoscaling/v2beta2
 kind: HorizontalPodAutoscaler
 metadata:
   name: custom-metrics-consumer
@@ -25,25 +25,36 @@ spec:
   # - type: Resource
   #   resource:
   #     name: cpu
-  #     targetAverageUtilization: 50
+  #     current:
+  #       averageUtilization: 50
+
   - type: Pods
     pods:
-      metricName: queue-length
-      targetAverageValue: 1k
+      metric:
+        name: queue-length
+      target:
+        averageValue: 1k
+        type: AverageValue
+
   - type: Object
     object:
-      metricName: requests-per-second
-      target:
+      describedObject:
         apiVersion: extensions/v1beta1
         kind: Ingress
         name: custom-metrics-consumer
-      averageValue: 10
-      targetValue: 10 # this must be set, but has no effect if `averageValue` is defined.
+      metric:
+        name: requests-per-second
+      target:
+        averageValue: "10"
+        type: AverageValue
   - type: External
     external:
-      metricName: sqs-queue-length
-      metricSelector:
-        matchLabels:
-          queue-name: foobar
-          region: eu-central-1
-      targetAverageValue: 30
+      metric:
+        name: sqs-queue-length
+        selector:
+          matchLabels:
+            queue-name: foobar
+            region: eu-central-1
+      target:
+        averageValue: "30"
+        type: AverageValue

go.mod

@@ -2,32 +2,30 @@ module github.com/zalando-incubator/kube-metrics-adapter
 
 require (
 	github.com/NYTimes/gziphandler v1.0.1 // indirect
-	github.com/aws/aws-sdk-go v1.16.6
-	github.com/coreos/go-systemd v0.0.0-20180705093442-88bfeed483d3 // indirect
-	github.com/golang/groupcache v0.0.0-20180513044358-24b0969c4cb7 // indirect
+	github.com/aws/aws-sdk-go v1.35.0
 	github.com/googleapis/gnostic v0.2.0 // indirect
-	github.com/grpc-ecosystem/grpc-gateway v1.4.1 // indirect
-	github.com/imdario/mergo v0.3.6 // indirect
-	github.com/inconshreveable/mousetrap v1.0.0 // indirect
-	github.com/kubernetes-incubator/custom-metrics-apiserver v0.0.0-20190918110929-3d9be26a50eb
-	github.com/oliveagle/jsonpath v0.0.0-20180606110733-2e52cf6e6852
-	github.com/prometheus/client_golang v0.9.2
-	github.com/prometheus/common v0.0.0-20181126121408-4724e9255275
-	github.com/sirupsen/logrus v1.4.2
-	github.com/soheilhy/cmux v0.1.4 // indirect
-	github.com/spf13/cobra v0.0.3
-	github.com/stretchr/testify v1.3.0
-	github.com/tmc/grpc-websocket-proxy v0.0.0-20171017195756-830351dc03c6 // indirect
+	github.com/influxdata/influxdb-client-go v0.1.5
+	github.com/kubernetes-incubator/custom-metrics-apiserver v0.0.0-20200618121405-54026617ec44
+	github.com/lib/pq v1.2.0 // indirect
+	github.com/mattn/go-colorable v0.1.4 // indirect
+	github.com/onsi/gomega v1.8.1 // indirect
+	github.com/prometheus/client_golang v1.7.1
+	github.com/prometheus/common v0.14.0
+	github.com/sirupsen/logrus v1.7.0
+	github.com/spf13/cobra v0.0.7
+	github.com/spyzhov/ajson v0.4.2
+	github.com/stretchr/testify v1.6.1
 	github.com/zalando-incubator/cluster-lifecycle-manager v0.0.0-20180921141935-824b77fb1f84
 	golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45
-	gopkg.in/inf.v0 v0.9.1 // indirect
-	k8s.io/api v0.0.0-20190918155943-95b840bb6a1f
-	k8s.io/apimachinery v0.0.0-20190913080033-27d36303b655
-	k8s.io/apiserver v0.0.0-20190918160949-bfa5e2e684ad // indirect
-	k8s.io/client-go v0.0.0-20190918160344-1fbdaa4c8d90
-	k8s.io/component-base v0.0.0-20190918160511-547f6c5d7090
-	k8s.io/klog v0.4.0
-	k8s.io/metrics v0.0.0-20190226180357-f3f09b9076d1
+	golang.org/x/tools v0.0.0-20200204192400-7124308813f3 // indirect
+	gonum.org/v1/netlib v0.0.0-20190331212654-76723241ea4e // indirect
+	honnef.co/go/tools v0.0.1-2020.1.3 // indirect
+	k8s.io/api v0.18.8
+	k8s.io/apimachinery v0.18.8
+	k8s.io/client-go v0.18.8
+	k8s.io/component-base v0.18.8
+	k8s.io/klog v1.0.0
+	k8s.io/metrics v0.18.8
 )
 
 go 1.13

main.go

@@ -18,6 +18,7 @@ package main
 
 import (
 	"flag"
+	_ "net/http/pprof"
 	"os"
 	"runtime"
 

pkg/annotations/parser_test.go

@@ -65,6 +65,42 @@ func TestParser(t *testing.T) {
 			},
 			PerReplica: false,
 		},
+		{
+			Name: "influxdb metrics",
+			Annotations: map[string]string{
+				"metric-config.external.flux-query.influxdb/range1m": `from(bucket: "?") |> range(start: -1m)`,
+				"metric-config.external.flux-query.influxdb/range2m": `from(bucket: "?") |> range(start: -2m)`,
+				"metric-config.external.flux-query.influxdb/range3m": `from(bucket: "?") |> range(start: -3m)`,
+				"metric-config.external.flux-query.influxdb/address": "http://localhost:9999",
+				"metric-config.external.flux-query.influxdb/token":   "sEcr3TT0ken",
+				"metric-config.external.flux-query.influxdb/org-id":  "deadbeef",
+			},
+			MetricName: "flux-query",
+			MetricType: autoscalingv2.ExternalMetricSourceType,
+			ExpectedConfig: map[string]string{
+				"range1m": `from(bucket: "?") |> range(start: -1m)`,
+				"range2m": `from(bucket: "?") |> range(start: -2m)`,
+				"range3m": `from(bucket: "?") |> range(start: -3m)`,
+				"address": "http://localhost:9999",
+				"token":   "sEcr3TT0ken",
+				"org-id":  "deadbeef",
+			},
+		},
+		{
+			Name: "http metrics",
+			Annotations: map[string]string{
+				"metric-config.external.http.json/json-key":   "$.metric.value",
+				"metric-config.external.http.json/endpoint":   "http://metric-source.source-namespace.svc.cluster.local:8000/metrics",
+				"metric-config.external.http.json/aggregator": "avg",
+			},
+			MetricName: "http",
+			MetricType: autoscalingv2.ExternalMetricSourceType,
+			ExpectedConfig: map[string]string{
+				"json-key":   "$.metric.value",
+				"endpoint":   "http://metric-source.source-namespace.svc.cluster.local:8000/metrics",
+				"aggregator": "avg",
+			},
+		},
 	} {
 		t.Run(tc.Name, func(t *testing.T) {
 			hpaMap := make(AnnotationConfigMap)

pkg/collector/collector.go

@@ -46,6 +46,14 @@ type CollectorPlugin interface {
 	NewCollector(hpa *autoscalingv2.HorizontalPodAutoscaler, config *MetricConfig, interval time.Duration) (Collector, error)
 }
 
+type PluginNotFoundError struct {
+	metricTypeName MetricTypeName
+}
+
+func (p *PluginNotFoundError) Error() string {
+	return fmt.Sprintf("no plugin found for %s", p.metricTypeName)
+}
+
 func (c *CollectorFactory) RegisterPodsCollector(metricCollector string, plugin CollectorPlugin) error {
 	if metricCollector == "" {
 		c.podsPlugins.Any = plugin
@@ -139,7 +147,7 @@ func (c *CollectorFactory) NewCollector(hpa *autoscalingv2.HorizontalPodAutoscal
 		}
 	}
 
-	return nil, fmt.Errorf("no plugin found for %s", config.MetricTypeName)
+	return nil, &PluginNotFoundError{metricTypeName: config.MetricTypeName}
 }
 
 type MetricTypeName struct {
@@ -213,7 +221,9 @@ func ParseHPAMetrics(hpa *autoscalingv2.HorizontalPodAutoscaler) ([]*MetricConfi
 		if metric.Type == autoscalingv2.ExternalMetricSourceType &&
 			metric.External.Metric.Selector != nil &&
 			metric.External.Metric.Selector.MatchLabels != nil {
-			config.Config = metric.External.Metric.Selector.MatchLabels
+			for k, v := range metric.External.Metric.Selector.MatchLabels {
+				config.Config[k] = v
+			}
 		}
 
 		annotationConfigs, present := parser.GetAnnotationConfig(typeName.Metric.Name, typeName.Type)

pkg/collector/http_collector.go

@@ -0,0 +1,103 @@
+package collector
+
+import (
+	"fmt"
+	"net/url"
+	"time"
+
+	"github.com/zalando-incubator/kube-metrics-adapter/pkg/collector/httpmetrics"
+
+	"k8s.io/api/autoscaling/v2beta2"
+	"k8s.io/apimachinery/pkg/api/resource"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/metrics/pkg/apis/external_metrics"
+)
+
+const (
+	HTTPMetricName            = "http"
+	HTTPEndpointAnnotationKey = "endpoint"
+	HTTPJsonPathAnnotationKey = "json-key"
+	identifierLabel           = "identifier"
+)
+
+type HTTPCollectorPlugin struct{}
+
+func NewHTTPCollectorPlugin() (*HTTPCollectorPlugin, error) {
+	return &HTTPCollectorPlugin{}, nil
+}
+
+func (p *HTTPCollectorPlugin) NewCollector(_ *v2beta2.HorizontalPodAutoscaler, config *MetricConfig, interval time.Duration) (Collector, error) {
+	collector := &HTTPCollector{}
+	var (
+		value string
+		ok    bool
+	)
+	if value, ok = config.Config[HTTPJsonPathAnnotationKey]; !ok {
+		return nil, fmt.Errorf("config value %s not found", HTTPJsonPathAnnotationKey)
+	}
+	jsonPath := value
+
+	if value, ok = config.Config[HTTPEndpointAnnotationKey]; !ok {
+		return nil, fmt.Errorf("config value %s not found", HTTPEndpointAnnotationKey)
+	}
+	var err error
+	collector.endpoint, err = url.Parse(value)
+	if err != nil {
+		return nil, err
+	}
+	collector.interval = interval
+	collector.metricType = config.Type
+	if config.Metric.Selector == nil || config.Metric.Selector.MatchLabels == nil {
+		return nil, fmt.Errorf("no label selector specified for metric: %s", config.Metric.Name)
+	}
+	if _, ok := config.Metric.Selector.MatchLabels[identifierLabel]; !ok {
+		return nil, fmt.Errorf("%s is not specified as a label for metric %s", identifierLabel, config.Metric.Name)
+	}
+	collector.metric = config.Metric
+	var aggFunc httpmetrics.AggregatorFunc
+
+	if val, ok := config.Config["aggregator"]; ok {
+		aggFunc, err = httpmetrics.ParseAggregator(val)
+		if err != nil {
+			return nil, err
+		}
+	}
+	jsonPathGetter, err := httpmetrics.NewJSONPathMetricsGetter(httpmetrics.DefaultMetricsHTTPClient(), aggFunc, jsonPath)
+	if err != nil {
+		return nil, err
+	}
+	collector.metricsGetter = jsonPathGetter
+	return collector, nil
+}
+
+type HTTPCollector struct {
+	endpoint      *url.URL
+	interval      time.Duration
+	metricType    v2beta2.MetricSourceType
+	metricsGetter *httpmetrics.JSONPathMetricsGetter
+	metric        v2beta2.MetricIdentifier
+}
+
+func (c *HTTPCollector) GetMetrics() ([]CollectedMetric, error) {
+	metric, err := c.metricsGetter.GetMetric(*c.endpoint)
+	if err != nil {
+		return nil, err
+	}
+
+	value := CollectedMetric{
+		Type: c.metricType,
+		External: external_metrics.ExternalMetricValue{
+			MetricName:   c.metric.Name,
+			MetricLabels: c.metric.Selector.MatchLabels,
+			Timestamp: metav1.Time{
+				Time: time.Now(),
+			},
+			Value: *resource.NewMilliQuantity(int64(metric*1000), resource.DecimalSI),
+		},
+	}
+	return []CollectedMetric{value}, nil
+}
+
+func (c *HTTPCollector) Interval() time.Duration {
+	return c.interval
+}

pkg/collector/http_collector_test.go

@@ -0,0 +1,94 @@
+package collector
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"k8s.io/api/autoscaling/v2beta2"
+	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+type testExternalMetricsHandler struct {
+	values []int64
+	test   *testing.T
+}
+
+func (t testExternalMetricsHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	response, err := json.Marshal(testMetricResponse{t.values})
+	require.NoError(t.test, err)
+	w.Header().Set("Content-Type", "application/json")
+	_, err = w.Write(response)
+	require.NoError(t.test, err)
+}
+
+func makeHTTPTestServer(t *testing.T, values []int64) string {
+	server := httptest.NewServer(&testExternalMetricsHandler{values: values, test: t})
+	return server.URL
+}
+
+func TestHTTPCollector(t *testing.T) {
+	for _, tc := range []struct {
+		name       string
+		values     []int64
+		output     int
+		aggregator string
+	}{
+		{
+			name:       "basic",
+			values:     []int64{3},
+			output:     3,
+			aggregator: "sum",
+		},
+		{
+			name:       "sum",
+			values:     []int64{3, 5, 6},
+			aggregator: "sum",
+			output:     14,
+		},
+		{
+			name:       "average",
+			values:     []int64{3, 5, 6},
+			aggregator: "sum",
+			output:     14,
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			testServer := makeHTTPTestServer(t, tc.values)
+			plugin, err := NewHTTPCollectorPlugin()
+			require.NoError(t, err)
+			testConfig := makeTestHTTPCollectorConfig(testServer, tc.aggregator)
+			collector, err := plugin.NewCollector(nil, testConfig, testInterval)
+			require.NoError(t, err)
+			metrics, err := collector.GetMetrics()
+			require.NoError(t, err)
+			require.NotNil(t, metrics)
+			require.Len(t, metrics, 1)
+			require.EqualValues(t, metrics[0].External.Value.Value(), tc.output)
+		})
+	}
+}
+
+func makeTestHTTPCollectorConfig(endpoint, aggregator string) *MetricConfig {
+	config := &MetricConfig{
+		MetricTypeName: MetricTypeName{
+			Type: v2beta2.ExternalMetricSourceType,
+			Metric: v2beta2.MetricIdentifier{
+				Name: "test-metric",
+				Selector: &v1.LabelSelector{
+					MatchLabels: map[string]string{identifierLabel: "test-metric"},
+				},
+			},
+		},
+		Config: map[string]string{
+			HTTPJsonPathAnnotationKey: "$.values",
+			HTTPEndpointAnnotationKey: endpoint,
+		},
+	}
+	if aggregator != "" {
+		config.Config["aggregator"] = aggregator
+	}
+	return config
+}

pkg/collector/httpmetrics/aggregator.go

@@ -0,0 +1,65 @@
+package httpmetrics
+
+import (
+	"fmt"
+	"math"
+)
+
+type AggregatorFunc func(...float64) float64
+
+// Average implements the average mathematical function over a slice of float64
+func Average(values ...float64) float64 {
+	sum := Sum(values...)
+	return sum / float64(len(values))
+}
+
+// Minimum implements the absolute minimum mathematical function over a slice of float64
+func Minimum(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
+}
+
+// Maximum implements the absolute maximum mathematical function over a slice of float64
+func Maximum(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
+}
+
+// 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 ParseAggregator(aggregator string) (AggregatorFunc, error) {
+	switch aggregator {
+	case "avg":
+		return Average, nil
+	case "min":
+		return Minimum, nil
+	case "max":
+		return Maximum, nil
+	case "sum":
+		return Sum, nil
+	default:
+		return nil, fmt.Errorf("aggregator function: %s is unknown", aggregator)
+	}
+}

pkg/collector/httpmetrics/aggregator_test.go

@@ -0,0 +1,57 @@
+package httpmetrics
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestReduce(t *testing.T) {
+	for _, tc := range []struct {
+		input      []float64
+		output     float64
+		aggregator string
+		parseError bool
+	}{
+		{
+			input:      []float64{1, 2, 3},
+			output:     2.0,
+			aggregator: "avg",
+			parseError: false,
+		},
+		{
+			input:      []float64{1, 2, 3},
+			output:     1.0,
+			aggregator: "min",
+			parseError: false,
+		},
+		{
+			input:      []float64{1, 2, 3},
+			output:     3.0,
+			aggregator: "max",
+			parseError: false,
+		},
+		{
+			input:      []float64{1, 2, 3},
+			output:     6.0,
+			aggregator: "sum",
+			parseError: false,
+		},
+		{
+			input:      []float64{1, 2, 3},
+			aggregator: "non-existent",
+			parseError: true,
+		},
+	} {
+		t.Run(fmt.Sprintf("Test function: %s", tc.aggregator), func(t *testing.T) {
+			aggFunc, err := ParseAggregator(tc.aggregator)
+			if tc.parseError {
+				require.Error(t, err)
+			} else {
+				val := aggFunc(tc.input...)
+				require.Equal(t, tc.output, val)
+			}
+		})
+	}
+}

pkg/collector/httpmetrics/json_path.go

@@ -0,0 +1,128 @@
+package httpmetrics
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"net/url"
+	"time"
+
+	"github.com/spyzhov/ajson"
+)
+
+// JSONPathMetricsGetter is a metrics getter which looks up pod metrics by
+// querying the pods metrics endpoint and lookup the metric value as defined by
+// the json path query.
+type JSONPathMetricsGetter struct {
+	jsonPath   string
+	aggregator AggregatorFunc
+	client     *http.Client
+}
+
+// NewJSONPathMetricsGetter initializes a new JSONPathMetricsGetter.
+func NewJSONPathMetricsGetter(httpClient *http.Client, aggregatorFunc AggregatorFunc, jsonPath string) (*JSONPathMetricsGetter, error) {
+	// check that jsonPath parses
+	_, err := ajson.ParseJSONPath(jsonPath)
+	if err != nil {
+		return nil, err
+	}
+	return &JSONPathMetricsGetter{client: httpClient, aggregator: aggregatorFunc, jsonPath: jsonPath}, nil
+}
+
+var DefaultRequestTimeout = 15 * time.Second
+var DefaultConnectTimeout = 15 * time.Second
+
+func CustomMetricsHTTPClient(requestTimeout time.Duration, connectTimeout time.Duration) *http.Client {
+	client := &http.Client{
+		Transport: &http.Transport{
+			DialContext: (&net.Dialer{
+				Timeout: connectTimeout,
+			}).DialContext,
+			MaxIdleConns:          50,
+			IdleConnTimeout:       90 * time.Second,
+			ExpectContinueTimeout: 1 * time.Second,
+		},
+		Timeout: requestTimeout,
+	}
+	return client
+}
+
+func DefaultMetricsHTTPClient() *http.Client {
+	return CustomMetricsHTTPClient(DefaultRequestTimeout, DefaultConnectTimeout)
+}
+
+// GetMetric gets metric from pod by fetching json metrics from the pods metric
+// endpoint and extracting the desired value using the specified json path
+// query.
+func (g *JSONPathMetricsGetter) GetMetric(metricsURL url.URL) (float64, error) {
+	data, err := g.fetchMetrics(metricsURL)
+	if err != nil {
+		return 0, err
+	}
+
+	// parse data
+	root, err := ajson.Unmarshal(data)
+	if err != nil {
+		return 0, err
+	}
+
+	nodes, err := root.JSONPath(g.jsonPath)
+	if err != nil {
+		return 0, err
+	}
+
+	if len(nodes) != 1 {
+		return 0, fmt.Errorf("unexpected json: expected single numeric or array value")
+	}
+
+	node := nodes[0]
+	if node.IsArray() {
+		if g.aggregator == nil {
+			return 0, fmt.Errorf("no aggregator function has been specified")
+		}
+		values := make([]float64, 0, len(nodes))
+		items, _ := node.GetArray()
+		for _, item := range items {
+			value, err := item.GetNumeric()
+			if err != nil {
+				return 0, fmt.Errorf("did not find numeric type: %w", err)
+			}
+			values = append(values, value)
+		}
+		return g.aggregator(values...), nil
+	} else if node.IsNumeric() {
+		res, _ := node.GetNumeric()
+		return res, nil
+	}
+
+	value, err := node.Value()
+	if err != nil {
+		return 0, fmt.Errorf("failed to check value of jsonPath result: %w", err)
+	}
+	return 0, fmt.Errorf("unsupported type %T", value)
+}
+
+func (g *JSONPathMetricsGetter) fetchMetrics(metricsURL url.URL) ([]byte, error) {
+	request, err := http.NewRequest(http.MethodGet, metricsURL.String(), nil)
+	if err != nil {
+		return nil, err
+	}
+
+	resp, err := g.client.Do(request)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	data, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("unsuccessful response: %s", resp.Status)
+	}
+
+	return data, nil
+}

pkg/collector/httpmetrics/json_path_test.go

@@ -0,0 +1,84 @@
+package httpmetrics
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func makeTestHTTPServer(t *testing.T, response []byte) *httptest.Server {
+	h := func(w http.ResponseWriter, r *http.Request) {
+		require.Equal(t, r.URL.Path, "/metrics")
+		w.Header().Set("Content-Type", "application/json")
+		_, err := w.Write(response)
+		require.NoError(t, err)
+	}
+	return httptest.NewServer(http.HandlerFunc(h))
+}
+
+func TestJSONPathMetricsGetter(t *testing.T) {
+	for _, tc := range []struct {
+		name         string
+		jsonResponse []byte
+		jsonPath     string
+		result       float64
+		aggregator   AggregatorFunc
+		err          error
+	}{
+		{
+			name:         "basic single value",
+			jsonResponse: []byte(`{"value":3}`),
+			jsonPath:     "$.value",
+			result:       3,
+			aggregator:   Average,
+		},
+		{
+			name:         "basic average",
+			jsonResponse: []byte(`{"value":[3,4,5]}`),
+			jsonPath:     "$.value",
+			result:       4,
+			aggregator:   Average,
+		},
+		{
+			name:         "dotted key",
+			jsonResponse: []byte(`{"metric.value":5}`),
+			jsonPath:     "$['metric.value']",
+			result:       5,
+			aggregator:   Average,
+		},
+		{
+			name:         "json path not resulting in array or number should lead to error",
+			jsonResponse: []byte(`{"metric.value":5}`),
+			jsonPath:     "$['invalid.metric.values']",
+			err:          errors.New("unexpected json: expected single numeric or array value"),
+		},
+		{
+			name:         "invalid json should error",
+			jsonResponse: []byte(`{`),
+			jsonPath:     "$['invalid.metric.values']",
+			err:          errors.New("unexpected end of file"),
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			server := makeTestHTTPServer(t, tc.jsonResponse)
+			defer server.Close()
+			getter, err := NewJSONPathMetricsGetter(DefaultMetricsHTTPClient(), tc.aggregator, tc.jsonPath)
+			require.NoError(t, err)
+			url, err := url.Parse(fmt.Sprintf("%s/metrics", server.URL))
+			require.NoError(t, err)
+			metric, err := getter.GetMetric(*url)
+			if tc.err != nil {
+				require.Error(t, err)
+				require.Equal(t, tc.err.Error(), err.Error())
+				return
+			}
+			require.NoError(t, err)
+			require.Equal(t, tc.result, metric)
+		})
+	}
+}

pkg/collector/httpmetrics/pod_metrics.go

@@ -0,0 +1,118 @@
+package httpmetrics
+
+import (
+	"fmt"
+	"net/url"
+	"strconv"
+	"time"
+
+	v1 "k8s.io/api/core/v1"
+)
+
+type PodMetricsGetter interface {
+	GetMetric(pod *v1.Pod) (float64, error)
+}
+
+type PodMetricsJSONPathGetter struct {
+	scheme       string
+	path         string
+	rawQuery     string
+	port         int
+	metricGetter *JSONPathMetricsGetter
+}
+
+func (g PodMetricsJSONPathGetter) GetMetric(pod *v1.Pod) (float64, error) {
+	if pod.Status.PodIP == "" {
+		return 0, fmt.Errorf("pod %s/%s does not have a pod IP", pod.Namespace, pod.Name)
+	}
+	metricsURL := g.buildMetricsURL(pod.Status.PodIP)
+	return g.metricGetter.GetMetric(metricsURL)
+}
+
+func NewPodMetricsJSONPathGetter(config map[string]string) (*PodMetricsJSONPathGetter, error) {
+	getter := PodMetricsJSONPathGetter{}
+	var (
+		jsonPath   string
+		aggregator AggregatorFunc
+		err        error
+	)
+
+	if v, ok := config["json-key"]; ok {
+		jsonPath = v
+	}
+
+	if v, ok := config["scheme"]; ok {
+		getter.scheme = v
+	}
+
+	if v, ok := config["path"]; ok {
+		getter.path = v
+	}
+
+	if v, ok := config["raw-query"]; ok {
+		getter.rawQuery = v
+	}
+
+	if v, ok := config["port"]; ok {
+		n, err := strconv.Atoi(v)
+		if err != nil {
+			return nil, err
+		}
+		getter.port = n
+	}
+
+	if v, ok := config["aggregator"]; ok {
+		aggregator, err = ParseAggregator(v)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	requestTimeout := DefaultRequestTimeout
+	connectTimeout := DefaultConnectTimeout
+
+	if v, ok := config["request-timeout"]; ok {
+		d, err := time.ParseDuration(v)
+		if err != nil {
+			return nil, err
+		}
+		if d < 0 {
+			return nil, fmt.Errorf("Invalid request-timeout config value: %s", v)
+		}
+		requestTimeout = d
+	}
+
+	if v, ok := config["connect-timeout"]; ok {
+		d, err := time.ParseDuration(v)
+		if err != nil {
+			return nil, err
+		}
+		if d < 0 {
+			return nil, fmt.Errorf("Invalid connect-timeout config value: %s", v)
+		}
+		connectTimeout = d
+	}
+
+	jsonPathGetter, err := NewJSONPathMetricsGetter(CustomMetricsHTTPClient(requestTimeout, connectTimeout), aggregator, jsonPath)
+	if err != nil {
+		return nil, err
+	}
+	getter.metricGetter = jsonPathGetter
+	return &getter, nil
+}
+
+// buildMetricsURL will build the full URL needed to hit the pod metric endpoint.
+func (g *PodMetricsJSONPathGetter) buildMetricsURL(podIP string) url.URL {
+	var scheme = g.scheme
+
+	if scheme == "" {
+		scheme = "http"
+	}
+
+	return url.URL{
+		Scheme:   scheme,
+		Host:     fmt.Sprintf("%s:%d", podIP, g.port),
+		Path:     g.path,
+		RawQuery: g.rawQuery,
+	}
+}

pkg/collector/httpmetrics/pod_metrics_test.go

@@ -0,0 +1,190 @@
+package httpmetrics
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+func compareMetricsGetter(t *testing.T, first, second *PodMetricsJSONPathGetter) {
+	require.Equal(t, first.metricGetter.jsonPath, second.metricGetter.jsonPath)
+	require.Equal(t, first.scheme, second.scheme)
+	require.Equal(t, first.path, second.path)
+	require.Equal(t, first.port, second.port)
+}
+
+func TestNewPodJSONPathMetricsGetter(t *testing.T) {
+	configNoAggregator := map[string]string{
+		"json-key": "$.value",
+		"scheme":   "http",
+		"path":     "/metrics",
+		"port":     "9090",
+	}
+	getterNoAggregator, err1 := NewPodMetricsJSONPathGetter(configNoAggregator)
+
+	require.NoError(t, err1)
+	compareMetricsGetter(t, &PodMetricsJSONPathGetter{
+		metricGetter: &JSONPathMetricsGetter{jsonPath: configNoAggregator["json-key"]},
+		scheme:       "http",
+		path:         "/metrics",
+		port:         9090,
+	}, getterNoAggregator)
+
+	configAggregator := map[string]string{
+		"json-key":   "$.values",
+		"scheme":     "http",
+		"path":       "/metrics",
+		"port":       "9090",
+		"aggregator": "avg",
+	}
+	getterAggregator, err2 := NewPodMetricsJSONPathGetter(configAggregator)
+
+	require.NoError(t, err2)
+	compareMetricsGetter(t, &PodMetricsJSONPathGetter{
+		metricGetter: &JSONPathMetricsGetter{jsonPath: configAggregator["json-key"], aggregator: Average},
+		scheme:       "http",
+		path:         "/metrics",
+		port:         9090,
+	}, getterAggregator)
+
+	configErrorJSONPath := map[string]string{
+		"json-key": "{}",
+		"scheme":   "http",
+		"path":     "/metrics",
+		"port":     "9090",
+	}
+
+	_, err3 := NewPodMetricsJSONPathGetter(configErrorJSONPath)
+	require.Error(t, err3)
+
+	configErrorPort := map[string]string{
+		"json-key": "$.values",
+		"scheme":   "http",
+		"path":     "/metrics",
+		"port":     "a9090",
+	}
+
+	_, err4 := NewPodMetricsJSONPathGetter(configErrorPort)
+	require.Error(t, err4)
+
+	configWithRawQuery := map[string]string{
+		"json-key":  "$.values",
+		"scheme":    "http",
+		"path":      "/metrics",
+		"port":      "9090",
+		"raw-query": "foo=bar&baz=bop",
+	}
+	getterWithRawQuery, err5 := NewPodMetricsJSONPathGetter(configWithRawQuery)
+
+	require.NoError(t, err5)
+	compareMetricsGetter(t, &PodMetricsJSONPathGetter{
+		metricGetter: &JSONPathMetricsGetter{jsonPath: configWithRawQuery["json-key"]},
+		scheme:       "http",
+		path:         "/metrics",
+		port:         9090,
+		rawQuery:     "foo=bar&baz=bop",
+	}, getterWithRawQuery)
+}
+
+func TestBuildMetricsURL(t *testing.T) {
+	scheme := "http"
+	ip := "1.2.3.4"
+	port := "9090"
+	path := "/v1/test/"
+	rawQuery := "foo=bar&baz=bop"
+
+	// Test building URL with rawQuery
+	configWithRawQuery := map[string]string{
+		"json-key":  "$.value",
+		"scheme":    scheme,
+		"path":      path,
+		"port":      port,
+		"raw-query": rawQuery,
+	}
+	getterWithRawQuery, err1 := NewPodMetricsJSONPathGetter(configWithRawQuery)
+	require.NoError(t, err1)
+
+	expectedURLWithQuery := fmt.Sprintf("%s://%s:%s%s?%s", scheme, ip, port, path, rawQuery)
+	receivedURLWithQuery := getterWithRawQuery.buildMetricsURL(ip)
+	require.Equal(t, receivedURLWithQuery.String(), expectedURLWithQuery)
+
+	// Test building URL without rawQuery
+	configWithNoQuery := map[string]string{
+		"json-key": "$.value",
+		"scheme":   scheme,
+		"path":     path,
+		"port":     port,
+	}
+	getterWithNoQuery, err3 := NewPodMetricsJSONPathGetter(configWithNoQuery)
+	require.NoError(t, err3)
+
+	expectedURLNoQuery := fmt.Sprintf("%s://%s:%s%s", scheme, ip, port, path)
+	receivedURLNoQuery := getterWithNoQuery.buildMetricsURL(ip)
+	require.Equal(t, receivedURLNoQuery.String(), expectedURLNoQuery)
+}
+
+func TestCustomTimeouts(t *testing.T) {
+	scheme := "http"
+	port := "9090"
+	path := "/v1/test/"
+
+	// Test no custom options results in default timeouts
+	defaultConfig := map[string]string{
+		"json-key": "$.value",
+		"scheme":   scheme,
+		"path":     path,
+		"port":     port,
+	}
+	defaultTime := time.Duration(15000) * time.Millisecond
+
+	defaultGetter, err1 := NewPodMetricsJSONPathGetter(defaultConfig)
+	require.NoError(t, err1)
+	require.Equal(t, defaultGetter.metricGetter.client.Timeout, defaultTime)
+
+	// Test with custom request timeout
+	configWithRequestTimeout := map[string]string{
+		"json-key":        "$.value",
+		"scheme":          scheme,
+		"path":            path,
+		"port":            port,
+		"request-timeout": "978ms",
+	}
+	exectedTimeout := time.Duration(978) * time.Millisecond
+	customRequestGetter, err2 := NewPodMetricsJSONPathGetter(configWithRequestTimeout)
+	require.NoError(t, err2)
+	require.Equal(t, customRequestGetter.metricGetter.client.Timeout, exectedTimeout)
+
+	// Test with custom connect timeout. Unfortunately, it seems there's no way to access the
+	// connect timeout of the client struct to actually verify it's set :/
+	configWithConnectTimeout := map[string]string{
+		"json-key":        "$.value",
+		"scheme":          scheme,
+		"path":            path,
+		"port":            port,
+		"connect-timeout": "512ms",
+	}
+	_, err3 := NewPodMetricsJSONPathGetter(configWithConnectTimeout)
+	require.NoError(t, err3)
+
+	configWithInvalidTimeout := map[string]string{
+		"json-key":        "$.value",
+		"scheme":          scheme,
+		"path":            path,
+		"port":            port,
+		"request-timeout": "-256ms",
+	}
+	_, err4 := NewPodMetricsJSONPathGetter(configWithInvalidTimeout)
+	require.Error(t, err4)
+
+	configWithInvalidTimeout = map[string]string{
+		"json-key":        "$.value",
+		"scheme":          scheme,
+		"path":            path,
+		"port":            port,
+		"connect-timeout": "-256ms",
+	}
+	_, err5 := NewPodMetricsJSONPathGetter(configWithInvalidTimeout)
+	require.Error(t, err5)
+}

pkg/collector/influxdb_collector.go

@@ -0,0 +1,152 @@
+package collector
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/influxdata/influxdb-client-go"
+	"k8s.io/api/autoscaling/v2beta2"
+	autoscalingv2 "k8s.io/api/autoscaling/v2beta2"
+	"k8s.io/apimachinery/pkg/api/resource"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/metrics/pkg/apis/external_metrics"
+)
+
+const (
+	InfluxDBMetricName        = "flux-query"
+	influxDBAddressKey        = "address"
+	influxDBTokenKey          = "token"
+	influxDBOrgKey            = "org"
+	influxDBQueryNameLabelKey = "query-name"
+)
+
+type InfluxDBCollectorPlugin struct {
+	kubeClient kubernetes.Interface
+	address    string
+	token      string
+	org        string
+}
+
+func NewInfluxDBCollectorPlugin(client kubernetes.Interface, address, token, org string) (*InfluxDBCollectorPlugin, error) {
+	return &InfluxDBCollectorPlugin{
+		kubeClient: client,
+		address:    address,
+		token:      token,
+		org:        org,
+	}, nil
+}
+
+func (p *InfluxDBCollectorPlugin) NewCollector(hpa *v2beta2.HorizontalPodAutoscaler, config *MetricConfig, interval time.Duration) (Collector, error) {
+	return NewInfluxDBCollector(p.address, p.token, p.org, config, interval)
+}
+
+type InfluxDBCollector struct {
+	address string
+	token   string
+	org     string
+
+	influxDBClient *influxdb.Client
+	interval       time.Duration
+	metric         autoscalingv2.MetricIdentifier
+	metricType     autoscalingv2.MetricSourceType
+	query          string
+}
+
+func NewInfluxDBCollector(address string, token string, org string, config *MetricConfig, interval time.Duration) (*InfluxDBCollector, error) {
+	collector := &InfluxDBCollector{
+		interval:   interval,
+		metric:     config.Metric,
+		metricType: config.Type,
+	}
+	switch configType := config.Type; configType {
+	case autoscalingv2.ObjectMetricSourceType:
+		return nil, fmt.Errorf("InfluxDB does not support object, but only external custom metrics")
+	case autoscalingv2.ExternalMetricSourceType:
+		// `metricSelector` is flattened into the MetricConfig.Config.
+		queryName, ok := config.Config[influxDBQueryNameLabelKey]
+		if !ok {
+			return nil, fmt.Errorf("selector for Flux query is not specified, "+
+				"please add metricSelector.matchLabels.%s: <...> to .yml description", influxDBQueryNameLabelKey)
+		}
+		if query, ok := config.Config[queryName]; ok {
+			// TODO(affo): validate the query once this is done:
+			//  https://github.com/influxdata/influxdb-client-go/issues/73.
+			collector.query = query
+		} else {
+			return nil, fmt.Errorf("no Flux query defined for metric \"%s\"", config.Metric.Name)
+		}
+	default:
+		return nil, fmt.Errorf("unknown metric type: %v", configType)
+	}
+	// Use custom InfluxDB config if defined in HPA annotation.
+	if v, ok := config.Config[influxDBAddressKey]; ok {
+		address = v
+	}
+	if v, ok := config.Config[influxDBTokenKey]; ok {
+		token = v
+	}
+	if v, ok := config.Config[influxDBOrgKey]; ok {
+		org = v
+	}
+	influxDbClient, err := influxdb.New(address, token)
+	if err != nil {
+		return nil, err
+	}
+	collector.address = address
+	collector.token = token
+	collector.org = org
+	collector.influxDBClient = influxDbClient
+	return collector, nil
+}
+
+// queryResult is for unmarshaling the result from InfluxDB.
+// The FluxQuery should make it so that the resulting table contains the column "metricvalue".
+type queryResult struct {
+	MetricValue float64
+}
+
+// getValue returns the first result gathered from an InfluxDB instance.
+func (c *InfluxDBCollector) getValue() (resource.Quantity, error) {
+	res, err := c.influxDBClient.QueryCSV(context.Background(), c.query, c.org)
+	if err != nil {
+		return resource.Quantity{}, err
+	}
+	defer res.Close()
+	// Keeping just the first result.
+	if res.Next() {
+		qr := queryResult{}
+		if err := res.Unmarshal(&qr); err != nil {
+			return resource.Quantity{}, fmt.Errorf("error in unmarshaling query result: %v", err)
+		}
+		return *resource.NewMilliQuantity(int64(qr.MetricValue*1000), resource.DecimalSI), nil
+	}
+	if err := res.Err; err != nil {
+		return resource.Quantity{}, fmt.Errorf("error in query result: %v", err)
+	}
+	return resource.Quantity{}, fmt.Errorf("empty result returned")
+}
+
+func (c *InfluxDBCollector) GetMetrics() ([]CollectedMetric, error) {
+	v, err := c.getValue()
+	if err != nil {
+		return nil, err
+	}
+	cm := CollectedMetric{
+		Type: c.metricType,
+		External: external_metrics.ExternalMetricValue{
+			MetricName:   c.metric.Name,
+			MetricLabels: c.metric.Selector.MatchLabels,
+			Timestamp: metav1.Time{
+				Time: time.Now().UTC(),
+			},
+			Value: v,
+		},
+	}
+	return []CollectedMetric{cm}, nil
+}
+
+func (c *InfluxDBCollector) Interval() time.Duration {
+	return c.interval
+}

pkg/collector/influxdb_collector_test.go

@@ -0,0 +1,155 @@
+package collector
+
+import (
+	"strings"
+	"testing"
+	"time"
+
+	"k8s.io/api/autoscaling/v2beta2"
+	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+func TestInfluxDBCollector_New(t *testing.T) {
+	t.Run("simple", func(t *testing.T) {
+		m := &MetricConfig{
+			MetricTypeName: MetricTypeName{
+				Type: v2beta2.ExternalMetricSourceType,
+				Metric: v2beta2.MetricIdentifier{
+					Name: "flux-query",
+					// This is actually useless, because the selector should be flattened in Config when parsing.
+					Selector: &v1.LabelSelector{
+						MatchLabels: map[string]string{
+							"query-name": "range2m",
+						},
+					},
+				},
+			},
+			CollectorName: "influxdb",
+			Config: map[string]string{
+				"range1m":    `from(bucket: "?") |> range(start: -1m)`,
+				"range2m":    `from(bucket: "?") |> range(start: -2m)`,
+				"range3m":    `from(bucket: "?") |> range(start: -3m)`,
+				"query-name": "range2m",
+			},
+		}
+		c, err := NewInfluxDBCollector("http://localhost:9999", "secret", "deadbeef", m, time.Second)
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+		if got, want := c.org, "deadbeef"; want != got {
+			t.Errorf("unexpected value -want/+got:\n\t-%s\n\t+%s", want, got)
+		}
+		if got, want := c.address, "http://localhost:9999"; want != got {
+			t.Errorf("unexpected value -want/+got:\n\t-%s\n\t+%s", want, got)
+		}
+		if got, want := c.token, "secret"; want != got {
+			t.Errorf("unexpected value -want/+got:\n\t-%s\n\t+%s", want, got)
+		}
+		if got, want := c.query, `from(bucket: "?") |> range(start: -2m)`; want != got {
+			t.Errorf("unexpected value -want/+got:\n\t-%s\n\t+%s", want, got)
+		}
+	})
+	t.Run("override params", func(t *testing.T) {
+		m := &MetricConfig{
+			MetricTypeName: MetricTypeName{
+				Type: v2beta2.ExternalMetricSourceType,
+				Metric: v2beta2.MetricIdentifier{
+					Name: "flux-query",
+					Selector: &v1.LabelSelector{
+						MatchLabels: map[string]string{
+							"query-name": "range2m",
+						},
+					},
+				},
+			},
+			CollectorName: "influxdb",
+			Config: map[string]string{
+				"range1m":    `from(bucket: "?") |> range(start: -1m)`,
+				"range2m":    `from(bucket: "?") |> range(start: -2m)`,
+				"range3m":    `from(bucket: "?") |> range(start: -3m)`,
+				"address":    "http://localhost:9999",
+				"token":      "sEcr3TT0ken",
+				"org":        "deadbeef1234",
+				"query-name": "range3m",
+			},
+		}
+		c, err := NewInfluxDBCollector("http://localhost:8888", "secret", "deadbeef", m, time.Second)
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+		if got, want := c.org, "deadbeef1234"; want != got {
+			t.Errorf("unexpected value -want/+got:\n\t-%s\n\t+%s", want, got)
+		}
+		if got, want := c.address, "http://localhost:9999"; want != got {
+			t.Errorf("unexpected value -want/+got:\n\t-%s\n\t+%s", want, got)
+		}
+		if got, want := c.token, "sEcr3TT0ken"; want != got {
+			t.Errorf("unexpected value -want/+got:\n\t-%s\n\t+%s", want, got)
+		}
+		if got, want := c.query, `from(bucket: "?") |> range(start: -3m)`; want != got {
+			t.Errorf("unexpected value -want/+got:\n\t-%s\n\t+%s", want, got)
+		}
+	})
+	// Errors.
+	for _, tc := range []struct {
+		name            string
+		mTypeName       MetricTypeName
+		config          map[string]string
+		errorStartsWith string
+	}{
+		{
+			name: "object metric",
+			mTypeName: MetricTypeName{
+				Type: v2beta2.ObjectMetricSourceType,
+			},
+			errorStartsWith: "InfluxDB does not support object",
+		},
+		{
+			name: "no selector",
+			mTypeName: MetricTypeName{
+				Type: v2beta2.ExternalMetricSourceType,
+				Metric: v2beta2.MetricIdentifier{
+					Name: "flux-query",
+				},
+			},
+			//  The selector should be flattened into the config by the parsing step, but it isn't.
+			config: map[string]string{
+				"range1m": `from(bucket: "?") |> range(start: -1m)`,
+				"range2m": `from(bucket: "?") |> range(start: -2m)`,
+				"range3m": `from(bucket: "?") |> range(start: -3m)`,
+			},
+			errorStartsWith: "selector for Flux query is not specified",
+		},
+		{
+			name: "referencing non-existing query",
+			mTypeName: MetricTypeName{
+				Type: v2beta2.ExternalMetricSourceType,
+				Metric: v2beta2.MetricIdentifier{
+					Name: "flux-query",
+				},
+			},
+			config: map[string]string{
+				"range1m":    `from(bucket: "?") |> range(start: -1m)`,
+				"range2m":    `from(bucket: "?") |> range(start: -2m)`,
+				"range3m":    `from(bucket: "?") |> range(start: -3m)`,
+				"query-name": "rangeXm",
+			},
+			errorStartsWith: "no Flux query defined for metric",
+		},
+	} {
+		t.Run("error - "+tc.name, func(t *testing.T) {
+			m := &MetricConfig{
+				MetricTypeName: tc.mTypeName,
+				CollectorName:  "influxdb",
+				Config:         tc.config,
+			}
+			_, err := NewInfluxDBCollector("http://localhost:9999", "secret", "deadbeef", m, time.Second)
+			if err == nil {
+				t.Fatal("expected error got none")
+			}
+			if want, got := tc.errorStartsWith, err.Error(); !strings.HasPrefix(got, want) {
+				t.Fatalf("%s should start with %s", got, want)
+			}
+		})
+	}
+}

pkg/collector/json_path_collector.go

@@ -1,133 +0,0 @@
-package collector
-
-import (
-	"encoding/json"
-	"fmt"
-	"io/ioutil"
-	"net/http"
-	"net/url"
-	"strconv"
-	"time"
-
-	"github.com/oliveagle/jsonpath"
-	corev1 "k8s.io/api/core/v1"
-)
-
-// JSONPathMetricsGetter is a metrics getter which looks up pod metrics by
-// querying the pods metrics endpoint and lookup the metric value as defined by
-// the json path query.
-type JSONPathMetricsGetter struct {
-	jsonPath *jsonpath.Compiled
-	scheme   string
-	path     string
-	port     int
-}
-
-// NewJSONPathMetricsGetter initializes a new JSONPathMetricsGetter.
-func NewJSONPathMetricsGetter(config map[string]string) (*JSONPathMetricsGetter, error) {
-	getter := &JSONPathMetricsGetter{}
-
-	if v, ok := config["json-key"]; ok {
-		pat, err := jsonpath.Compile(v)
-		if err != nil {
-			return nil, fmt.Errorf("failed to parse json path definition: %v", err)
-		}
-
-		getter.jsonPath = pat
-	}
-
-	if v, ok := config["scheme"]; ok {
-		getter.scheme = v
-	}
-
-	if v, ok := config["path"]; ok {
-		getter.path = v
-	}
-
-	if v, ok := config["port"]; ok {
-		n, err := strconv.Atoi(v)
-		if err != nil {
-			return nil, err
-		}
-		getter.port = n
-	}
-
-	return getter, nil
-}
-
-// GetMetric gets metric from pod by fetching json metrics from the pods metric
-// endpoint and extracting the desired value using the specified json path
-// query.
-func (g *JSONPathMetricsGetter) GetMetric(pod *corev1.Pod) (float64, error) {
-	data, err := getPodMetrics(pod, g.scheme, g.path, g.port)
-	if err != nil {
-		return 0, err
-	}
-
-	// parse data
-	var jsonData interface{}
-	err = json.Unmarshal(data, &jsonData)
-	if err != nil {
-		return 0, err
-	}
-
-	res, err := g.jsonPath.Lookup(jsonData)
-	if err != nil {
-		return 0, err
-	}
-
-	switch res := res.(type) {
-	case int:
-		return float64(res), nil
-	case float32:
-		return float64(res), nil
-	case float64:
-		return res, nil
-	default:
-		return 0, fmt.Errorf("unsupported type %T", res)
-	}
-}
-
-// 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 == "" {
-		return nil, fmt.Errorf("pod %s/%s does not have a pod IP", pod.Namespace, pod.Namespace)
-	}
-
-	httpClient := &http.Client{
-		Timeout:   15 * time.Second,
-		Transport: &http.Transport{},
-	}
-
-	if scheme == "" {
-		scheme = "http"
-	}
-
-	metricsURL := url.URL{
-		Scheme: scheme,
-		Host:   fmt.Sprintf("%s:%d", pod.Status.PodIP, port),
-		Path:   path,
-	}
-
-	request, err := http.NewRequest(http.MethodGet, metricsURL.String(), nil)
-	if err != nil {
-		return nil, err
-	}
-
-	resp, err := httpClient.Do(request)
-	if err != nil {
-		return nil, err
-	}
-	defer resp.Body.Close()
-
-	data, err := ioutil.ReadAll(resp.Body)
-	if err != nil {
-		return nil, err
-	}
-
-	if resp.StatusCode != http.StatusOK {
-		return nil, fmt.Errorf("unsuccessful response: %s", resp.Status)
-	}
-
-	return data, nil
-}

pkg/collector/pod_collector.go

@@ -1,10 +1,13 @@
 package collector
 
 import (
+	"context"
 	"fmt"
+	"net/http"
 	"time"
 
 	log "github.com/sirupsen/logrus"
+	"github.com/zalando-incubator/kube-metrics-adapter/pkg/collector/httpmetrics"
 	autoscalingv2 "k8s.io/api/autoscaling/v2beta2"
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
@@ -30,17 +33,14 @@ func (p *PodCollectorPlugin) NewCollector(hpa *autoscalingv2.HorizontalPodAutosc
 
 type PodCollector struct {
 	client           kubernetes.Interface
-	Getter           PodMetricsGetter
+	Getter           httpmetrics.PodMetricsGetter
 	podLabelSelector *metav1.LabelSelector
 	namespace        string
 	metric           autoscalingv2.MetricIdentifier
 	metricType       autoscalingv2.MetricSourceType
 	interval         time.Duration
 	logger           *log.Entry
-}
-
-type PodMetricsGetter interface {
-	GetMetric(pod *corev1.Pod) (float64, error)
+	httpClient       *http.Client
 }
 
 func NewPodCollector(client kubernetes.Interface, hpa *autoscalingv2.HorizontalPodAutoscaler, config *MetricConfig, interval time.Duration) (*PodCollector, error) {
@@ -60,11 +60,11 @@ func NewPodCollector(client kubernetes.Interface, hpa *autoscalingv2.HorizontalP
 		logger:           log.WithFields(log.Fields{"Collector": "Pod"}),
 	}
 
-	var getter PodMetricsGetter
+	var getter httpmetrics.PodMetricsGetter
 	switch config.CollectorName {
 	case "json-path":
 		var err error
-		getter, err = NewJSONPathMetricsGetter(config.Config)
+		getter, err = httpmetrics.NewPodMetricsJSONPathGetter(config.Config)
 		if err != nil {
 			return nil, err
 		}
@@ -82,37 +82,25 @@ func (c *PodCollector) GetMetrics() ([]CollectedMetric, error) {
 		LabelSelector: labels.Set(c.podLabelSelector.MatchLabels).String(),
 	}
 
-	pods, err := c.client.CoreV1().Pods(c.namespace).List(opts)
+	pods, err := c.client.CoreV1().Pods(c.namespace).List(context.TODO(), opts)
 	if err != nil {
 		return nil, err
 	}
 
-	values := make([]CollectedMetric, 0, len(pods.Items))
-
-	// TODO: get metrics in parallel
+	ch := make(chan CollectedMetric)
+	errCh := make(chan error)
 	for _, pod := range pods.Items {
-		value, err := c.Getter.GetMetric(&pod)
-		if err != nil {
-			c.logger.Errorf("Failed to get metrics from pod '%s/%s': %v", pod.Namespace, pod.Name, err)
-			continue
-		}
+		go c.getPodMetric(pod, ch, errCh)
+	}
 
-		metricValue := CollectedMetric{
-			Type: c.metricType,
-			Custom: custom_metrics.MetricValue{
-				DescribedObject: custom_metrics.ObjectReference{
-					APIVersion: "v1",
-					Kind:       "Pod",
-					Name:       pod.Name,
-					Namespace:  pod.Namespace,
-				},
-				Metric:    custom_metrics.MetricIdentifier{Name: c.metric.Name, Selector: c.podLabelSelector},
-				Timestamp: metav1.Time{Time: time.Now().UTC()},
-				Value:     *resource.NewMilliQuantity(int64(value*1000), resource.DecimalSI),
-			},
+	values := make([]CollectedMetric, 0, len(pods.Items))
+	for i := 0; i < len(pods.Items); i++ {
+		select {
+		case err := <-errCh:
+			c.logger.Error(err)
+		case resp := <-ch:
+			values = append(values, resp)
 		}
-
-		values = append(values, metricValue)
 	}
 
 	return values, nil
@@ -122,16 +110,39 @@ func (c *PodCollector) Interval() time.Duration {
 	return c.interval
 }
 
+func (c *PodCollector) getPodMetric(pod corev1.Pod, ch chan CollectedMetric, errCh chan error) {
+	value, err := c.Getter.GetMetric(&pod)
+	if err != nil {
+		errCh <- fmt.Errorf("Failed to get metrics from pod '%s/%s': %v", pod.Namespace, pod.Name, err)
+		return
+	}
+
+	ch <- CollectedMetric{
+		Type: c.metricType,
+		Custom: custom_metrics.MetricValue{
+			DescribedObject: custom_metrics.ObjectReference{
+				APIVersion: "v1",
+				Kind:       "Pod",
+				Name:       pod.Name,
+				Namespace:  pod.Namespace,
+			},
+			Metric:    custom_metrics.MetricIdentifier{Name: c.metric.Name, Selector: c.podLabelSelector},
+			Timestamp: metav1.Time{Time: time.Now().UTC()},
+			Value:     *resource.NewMilliQuantity(int64(value*1000), resource.DecimalSI),
+		},
+	}
+}
+
 func getPodLabelSelector(client kubernetes.Interface, hpa *autoscalingv2.HorizontalPodAutoscaler) (*metav1.LabelSelector, error) {
 	switch hpa.Spec.ScaleTargetRef.Kind {
 	case "Deployment":
-		deployment, err := client.AppsV1().Deployments(hpa.Namespace).Get(hpa.Spec.ScaleTargetRef.Name, metav1.GetOptions{})
+		deployment, err := client.AppsV1().Deployments(hpa.Namespace).Get(context.TODO(), hpa.Spec.ScaleTargetRef.Name, metav1.GetOptions{})
 		if err != nil {
 			return nil, err
 		}
 		return deployment.Spec.Selector, nil
 	case "StatefulSet":
-		sts, err := client.AppsV1().StatefulSets(hpa.Namespace).Get(hpa.Spec.ScaleTargetRef.Name, metav1.GetOptions{})
+		sts, err := client.AppsV1().StatefulSets(hpa.Namespace).Get(context.TODO(), hpa.Spec.ScaleTargetRef.Name, metav1.GetOptions{})
 		if err != nil {
 			return nil, err
 		}

pkg/collector/pod_collector_test.go

@@ -0,0 +1,156 @@
+package collector
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+	appsv1 "k8s.io/api/apps/v1"
+	autoscalingv2 "k8s.io/api/autoscaling/v2beta2"
+	corev1 "k8s.io/api/core/v1"
+	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/kubernetes/fake"
+)
+
+const (
+	testNamespace         = "test-namespace"
+	applicationLabelName  = "application"
+	applicationLabelValue = "test-application"
+	testDeploymentName    = "test-application"
+	testInterval          = 10 * time.Second
+)
+
+func TestPodCollector(t *testing.T) {
+	for _, tc := range []struct {
+		name    string
+		metrics [][]int64
+		result  []int64
+	}{
+		{
+			name:    "simple",
+			metrics: [][]int64{{1}, {3}, {8}, {5}, {2}},
+			result:  []int64{1, 3, 8, 5, 2},
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			client := fake.NewSimpleClientset()
+			plugin := NewPodCollectorPlugin(client)
+			makeTestDeployment(t, client)
+			host, port, metricsHandler := makeTestHTTPServer(t, tc.metrics)
+			makeTestPods(t, host, port, "test-metric", client, 5)
+			testHPA := makeTestHPA(t, client)
+			testConfig := makeTestConfig(port)
+			collector, err := plugin.NewCollector(testHPA, testConfig, testInterval)
+			require.NoError(t, err)
+			metrics, err := collector.GetMetrics()
+			require.NoError(t, err)
+			require.Equal(t, len(metrics), int(metricsHandler.calledCounter))
+			var values []int64
+			for _, m := range metrics {
+				values = append(values, m.Custom.Value.Value())
+			}
+			require.ElementsMatch(t, tc.result, values)
+		})
+	}
+}
+
+type testMetricResponse struct {
+	Values []int64 `json:"values"`
+}
+type testMetricsHandler struct {
+	values        [][]int64
+	calledCounter uint
+	t             *testing.T
+	metricsPath   string
+	sync.RWMutex
+}
+
+func (h *testMetricsHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	h.Lock()
+	defer h.Unlock()
+
+	require.Equal(h.t, h.metricsPath, r.URL.Path)
+	require.Less(h.t, int(h.calledCounter), len(h.values))
+	response, err := json.Marshal(testMetricResponse{Values: h.values[h.calledCounter]})
+	require.NoError(h.t, err)
+	w.Header().Set("Content-Type", "application/json")
+	_, err = w.Write(response)
+	require.NoError(h.t, err)
+	h.calledCounter++
+}
+
+func makeTestHTTPServer(t *testing.T, values [][]int64) (string, string, *testMetricsHandler) {
+	metricsHandler := &testMetricsHandler{values: values, t: t, metricsPath: "/metrics"}
+	server := httptest.NewServer(metricsHandler)
+	url, err := url.Parse(server.URL)
+	require.NoError(t, err)
+	return url.Hostname(), url.Port(), metricsHandler
+}
+
+func makeTestConfig(port string) *MetricConfig {
+	return &MetricConfig{
+		CollectorName: "json-path",
+		Config:        map[string]string{"json-key": "$.values", "port": port, "path": "/metrics", "aggregator": "sum"},
+	}
+}
+
+func makeTestPods(t *testing.T, testServer string, metricName string, port string, client kubernetes.Interface, replicas int) {
+	for i := 0; i < replicas; i++ {
+		testPod := &corev1.Pod{
+			ObjectMeta: v1.ObjectMeta{
+				Name:   fmt.Sprintf("test-pod-%d", i),
+				Labels: map[string]string{applicationLabelName: applicationLabelValue},
+				Annotations: map[string]string{
+					fmt.Sprintf("metric-config.pods.%s.json-path/port", metricName): port,
+				},
+			},
+			Status: corev1.PodStatus{
+				PodIP: testServer,
+			},
+		}
+		_, err := client.CoreV1().Pods(testNamespace).Create(context.TODO(), testPod, v1.CreateOptions{})
+		require.NoError(t, err)
+	}
+}
+
+func makeTestDeployment(t *testing.T, client kubernetes.Interface) *appsv1.Deployment {
+	deployment := appsv1.Deployment{
+		ObjectMeta: v1.ObjectMeta{Name: testDeploymentName},
+		Spec: appsv1.DeploymentSpec{
+			Selector: &v1.LabelSelector{
+				MatchLabels: map[string]string{applicationLabelName: applicationLabelValue},
+			},
+		},
+	}
+	_, err := client.AppsV1().Deployments(testNamespace).Create(context.TODO(), &deployment, v1.CreateOptions{})
+	require.NoError(t, err)
+	return &deployment
+
+}
+
+func makeTestHPA(t *testing.T, client kubernetes.Interface) *autoscalingv2.HorizontalPodAutoscaler {
+	hpa := &autoscalingv2.HorizontalPodAutoscaler{
+		ObjectMeta: v1.ObjectMeta{
+			Name:      "test-hpa",
+			Namespace: testNamespace,
+		},
+		Spec: autoscalingv2.HorizontalPodAutoscalerSpec{
+			ScaleTargetRef: autoscalingv2.CrossVersionObjectReference{
+				Kind:       "Deployment",
+				Name:       testDeploymentName,
+				APIVersion: "apps/v1",
+			},
+		},
+	}
+	_, err := client.AutoscalingV2beta2().HorizontalPodAutoscalers("test-namespace").Create(context.TODO(), hpa, v1.CreateOptions{})
+	require.NoError(t, err)
+	return hpa
+}

pkg/collector/prometheus_collector.go

@@ -128,7 +128,7 @@ func NewPrometheusCollector(client kubernetes.Interface, promAPI promv1.API, hpa
 
 func (c *PrometheusCollector) GetMetrics() ([]CollectedMetric, error) {
 	// TODO: use real context
-	value, err := c.promAPI.Query(context.Background(), c.query, time.Now().UTC())
+	value, _, err := c.promAPI.Query(context.Background(), c.query, time.Now().UTC())
 	if err != nil {
 		return nil, err
 	}

pkg/collector/skipper_collector.go

@@ -1,6 +1,7 @@
 package collector
 
 import (
+	"context"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -87,16 +88,16 @@ func NewSkipperCollector(client kubernetes.Interface, plugin CollectorPlugin, hp
 	}, nil
 }
 
-func getAnnotationWeight(backendWeights string, backend string) float64 {
-	var weightsMap map[string]int
+func getAnnotationWeight(backendWeights string, backend string) (float64, error) {
+	var weightsMap map[string]float64
 	err := json.Unmarshal([]byte(backendWeights), &weightsMap)
 	if err != nil {
-		return 0
+		return 0, err
 	}
 	if weight, ok := weightsMap[backend]; ok {
-		return float64(weight) / 100
+		return float64(weight) / 100, nil
 	}
-	return 0
+	return 0, nil
 }
 
 func getWeights(ingressAnnotations map[string]string, backendAnnotations []string, backend string) (float64, error) {
@@ -106,7 +107,11 @@ func getWeights(ingressAnnotations map[string]string, backendAnnotations []strin
 	for _, anno := range backendAnnotations {
 		if weightsMap, ok := ingressAnnotations[anno]; ok {
 			annotationsPresent = true
-			maxWeight = math.Max(maxWeight, getAnnotationWeight(weightsMap, backend))
+			weight, err := getAnnotationWeight(weightsMap, backend)
+			if err != nil {
+				return 0.0, err
+			}
+			maxWeight = math.Max(maxWeight, weight)
 		}
 	}
 
@@ -125,7 +130,7 @@ func getWeights(ingressAnnotations map[string]string, backendAnnotations []strin
 
 // getCollector returns a collector for getting the metrics.
 func (c *SkipperCollector) getCollector() (Collector, error) {
-	ingress, err := c.client.ExtensionsV1beta1().Ingresses(c.objectReference.Namespace).Get(c.objectReference.Name, metav1.GetOptions{})
+	ingress, err := c.client.NetworkingV1beta1().Ingresses(c.objectReference.Namespace).Get(context.TODO(), c.objectReference.Name, metav1.GetOptions{})
 	if err != nil {
 		return nil, err
 	}
@@ -207,13 +212,13 @@ func targetRefReplicas(client kubernetes.Interface, hpa *autoscalingv2.Horizonta
 	var replicas int32
 	switch hpa.Spec.ScaleTargetRef.Kind {
 	case "Deployment":
-		deployment, err := client.AppsV1().Deployments(hpa.Namespace).Get(hpa.Spec.ScaleTargetRef.Name, metav1.GetOptions{})
+		deployment, err := client.AppsV1().Deployments(hpa.Namespace).Get(context.TODO(), hpa.Spec.ScaleTargetRef.Name, metav1.GetOptions{})
 		if err != nil {
 			return 0, err
 		}
 		replicas = deployment.Status.Replicas
 	case "StatefulSet":
-		sts, err := client.AppsV1().StatefulSets(hpa.Namespace).Get(hpa.Spec.ScaleTargetRef.Name, metav1.GetOptions{})
+		sts, err := client.AppsV1().StatefulSets(hpa.Namespace).Get(context.TODO(), hpa.Spec.ScaleTargetRef.Name, metav1.GetOptions{})
 		if err != nil {
 			return 0, err
 		}

pkg/collector/skipper_collector_test.go

@@ -1,6 +1,7 @@
 package collector
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"testing"
@@ -10,7 +11,7 @@ import (
 	appsv1 "k8s.io/api/apps/v1"
 	autoscalingv2 "k8s.io/api/autoscaling/v2beta2"
 	corev1 "k8s.io/api/core/v1"
-	"k8s.io/api/extensions/v1beta1"
+	v1beta1 "k8s.io/api/networking/v1beta1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/kubernetes"
@@ -32,7 +33,7 @@ func TestTargetRefReplicasDeployments(t *testing.T) {
 
 	// Create an HPA with the deployment as ref
 	hpa, err := client.AutoscalingV2beta2().HorizontalPodAutoscalers(deployment.Namespace).
-		Create(newHPA(defaultNamespace, name, "Deployment"))
+		Create(context.TODO(), newHPA(defaultNamespace, name, "Deployment"), metav1.CreateOptions{})
 	require.NoError(t, err)
 
 	replicas, err := targetRefReplicas(client, hpa)
@@ -49,7 +50,7 @@ func TestTargetRefReplicasStatefulSets(t *testing.T) {
 
 	// Create an HPA with the statefulSet as ref
 	hpa, err := client.AutoscalingV2beta2().HorizontalPodAutoscalers(statefulSet.Namespace).
-		Create(newHPA(defaultNamespace, name, "StatefulSet"))
+		Create(context.TODO(), newHPA(defaultNamespace, name, "StatefulSet"), metav1.CreateOptions{})
 	require.NoError(t, err)
 
 	replicas, err := targetRefReplicas(client, hpa)
@@ -73,7 +74,7 @@ func newHPA(namesapce string, refName string, refKind string) *autoscalingv2.Hor
 }
 
 func newDeployment(client *fake.Clientset, namespace string, name string, replicas, readyReplicas int32) (*appsv1.Deployment, error) {
-	return client.AppsV1().Deployments(namespace).Create(&appsv1.Deployment{
+	return client.AppsV1().Deployments(namespace).Create(context.TODO(), &appsv1.Deployment{
 		ObjectMeta: metav1.ObjectMeta{
 			Name:      name,
 			Namespace: namespace,
@@ -83,11 +84,11 @@ func newDeployment(client *fake.Clientset, namespace string, name string, replic
 			ReadyReplicas: replicas,
 			Replicas:      readyReplicas,
 		},
-	})
+	}, metav1.CreateOptions{})
 }
 
 func newStatefulSet(client *fake.Clientset, namespace string, name string) (*appsv1.StatefulSet, error) {
-	return client.AppsV1().StatefulSets(namespace).Create(&appsv1.StatefulSet{
+	return client.AppsV1().StatefulSets(namespace).Create(context.TODO(), &appsv1.StatefulSet{
 		ObjectMeta: metav1.ObjectMeta{
 			Name:      name,
 			Namespace: namespace,
@@ -96,7 +97,7 @@ func newStatefulSet(client *fake.Clientset, namespace string, name string) (*app
 			ReadyReplicas: 1,
 			Replicas:      2,
 		},
-	})
+	}, metav1.CreateOptions{})
 }
 
 func TestSkipperCollector(t *testing.T) {
@@ -111,7 +112,7 @@ func TestSkipperCollector(t *testing.T) {
 		expectError        bool
 		fakedAverage       bool
 		namespace          string
-		backendWeights     map[string]map[string]int
+		backendWeights     map[string]map[string]float64
 		replicas           int32
 		readyReplicas      int32
 		backendAnnotations []string
@@ -137,7 +138,7 @@ func TestSkipperCollector(t *testing.T) {
 			collectedMetric:    1000,
 			namespace:          "default",
 			backend:            "backend1",
-			backendWeights:     map[string]map[string]int{testBackendWeightsAnnotation: {"backend2": 60, "backend1": 40}},
+			backendWeights:     map[string]map[string]float64{testBackendWeightsAnnotation: {"backend2": 60.0, "backend1": 40}},
 			replicas:           1,
 			readyReplicas:      1,
 			backendAnnotations: []string{testBackendWeightsAnnotation},
@@ -151,7 +152,7 @@ func TestSkipperCollector(t *testing.T) {
 			collectedMetric:    1000,
 			namespace:          "default",
 			backend:            "backend1",
-			backendWeights:     map[string]map[string]int{testBackendWeightsAnnotation: {"backend2": 60, "backend1": 40}},
+			backendWeights:     map[string]map[string]float64{testBackendWeightsAnnotation: {"backend2": 60, "backend1": 40}},
 			replicas:           1,
 			readyReplicas:      1,
 			backendAnnotations: []string{testBackendWeightsAnnotation},
@@ -166,7 +167,7 @@ func TestSkipperCollector(t *testing.T) {
 			fakedAverage:       true,
 			namespace:          "default",
 			backend:            "backend1",
-			backendWeights:     map[string]map[string]int{testBackendWeightsAnnotation: {"backend2": 50, "backend1": 50}},
+			backendWeights:     map[string]map[string]float64{testBackendWeightsAnnotation: {"backend2": 50, "backend1": 50}},
 			replicas:           5,
 			readyReplicas:      5,
 			backendAnnotations: []string{testBackendWeightsAnnotation},
@@ -180,7 +181,7 @@ func TestSkipperCollector(t *testing.T) {
 			collectedMetric:    1500,
 			namespace:          "default",
 			backend:            "backend1",
-			backendWeights:     map[string]map[string]int{testBackendWeightsAnnotation: {"backend2": 50, "backend1": 50}},
+			backendWeights:     map[string]map[string]float64{testBackendWeightsAnnotation: {"backend2": 50, "backend1": 50}},
 			replicas:           5, // this is not taken into account
 			readyReplicas:      5,
 			backendAnnotations: []string{testBackendWeightsAnnotation},
@@ -194,7 +195,7 @@ func TestSkipperCollector(t *testing.T) {
 			collectedMetric:    0,
 			namespace:          "default",
 			backend:            "backend1",
-			backendWeights:     map[string]map[string]int{testBackendWeightsAnnotation: {"backend2": 100, "backend1": 0}},
+			backendWeights:     map[string]map[string]float64{testBackendWeightsAnnotation: {"backend2": 100, "backend1": 0}},
 			replicas:           5,
 			readyReplicas:      5,
 			backendAnnotations: []string{testBackendWeightsAnnotation},
@@ -209,7 +210,7 @@ func TestSkipperCollector(t *testing.T) {
 			fakedAverage:    true,
 			namespace:       "default",
 			backend:         "backend1",
-			backendWeights: map[string]map[string]int{
+			backendWeights: map[string]map[string]float64{
 				testBackendWeightsAnnotation:  {"backend2": 20, "backend1": 80},
 				testStacksetWeightsAnnotation: {"backend2": 0, "backend1": 100},
 			},
@@ -226,7 +227,7 @@ func TestSkipperCollector(t *testing.T) {
 			collectedMetric: 1500,
 			namespace:       "default",
 			backend:         "backend1",
-			backendWeights: map[string]map[string]int{
+			backendWeights: map[string]map[string]float64{
 				testBackendWeightsAnnotation:  {"backend2": 20, "backend1": 80},
 				testStacksetWeightsAnnotation: {"backend2": 0, "backend1": 100},
 			},
@@ -243,7 +244,7 @@ func TestSkipperCollector(t *testing.T) {
 			collectedMetric:    0,
 			namespace:          "default",
 			backend:            "backend3",
-			backendWeights:     map[string]map[string]int{testBackendWeightsAnnotation: {"backend2": 100, "backend1": 0}},
+			backendWeights:     map[string]map[string]float64{testBackendWeightsAnnotation: {"backend2": 100, "backend1": 0}},
 			replicas:           1,
 			readyReplicas:      1,
 			backendAnnotations: []string{testBackendWeightsAnnotation},
@@ -257,7 +258,7 @@ func TestSkipperCollector(t *testing.T) {
 			collectedMetric:    1500,
 			namespace:          "default",
 			backend:            "backend3",
-			backendWeights:     map[string]map[string]int{},
+			backendWeights:     map[string]map[string]float64{},
 			replicas:           1,
 			readyReplicas:      1,
 			backendAnnotations: []string{testBackendWeightsAnnotation},
@@ -271,7 +272,7 @@ func TestSkipperCollector(t *testing.T) {
 			expectError:        true,
 			namespace:          "default",
 			backend:            "",
-			backendWeights:     map[string]map[string]int{testBackendWeightsAnnotation: {"backend2": 100, "backend1": 0}},
+			backendWeights:     map[string]map[string]float64{testBackendWeightsAnnotation: {"backend2": 100, "backend1": 0}},
 			replicas:           1,
 			readyReplicas:      1,
 			backendAnnotations: []string{testBackendWeightsAnnotation},
@@ -300,7 +301,7 @@ func TestSkipperCollector(t *testing.T) {
 			fakedAverage:    true,
 			namespace:       "default",
 			backend:         "backend2",
-			backendWeights: map[string]map[string]int{
+			backendWeights: map[string]map[string]float64{
 				testBackendWeightsAnnotation:  {"backend2": 20, "backend1": 80},
 				testStacksetWeightsAnnotation: {"backend1": 100},
 			},
@@ -313,12 +314,12 @@ func TestSkipperCollector(t *testing.T) {
 			metric:          1500,
 			ingressName:     "dummy-ingress",
 			hostnames:       []string{"example.org"},
-			expectedQuery:   `scalar(sum(rate(skipper_serve_host_duration_seconds_count{host=~"example_org"}[1m])) * 0.2000)`,
+			expectedQuery:   `scalar(sum(rate(skipper_serve_host_duration_seconds_count{host=~"example_org"}[1m])) * 0.2050)`,
 			collectedMetric: 1500,
 			namespace:       "default",
 			backend:         "backend2",
-			backendWeights: map[string]map[string]int{
-				testBackendWeightsAnnotation:  {"backend2": 20, "backend1": 80},
+			backendWeights: map[string]map[string]float64{
+				testBackendWeightsAnnotation:  {"backend2": 20.5, "backend1": 79.5},
 				testStacksetWeightsAnnotation: {"backend1": 100},
 			},
 			replicas:           5,
@@ -331,8 +332,8 @@ func TestSkipperCollector(t *testing.T) {
 			err := makeIngress(client, tc.namespace, tc.ingressName, tc.backend, tc.hostnames, tc.backendWeights)
 			require.NoError(t, err)
 			plugin := makePlugin(tc.metric)
-			hpa := makeHPA(tc.ingressName, tc.backend)
-			config := makeConfig(tc.backend, tc.fakedAverage)
+			hpa := makeHPA(tc.namespace, tc.ingressName, tc.backend)
+			config := makeConfig(tc.ingressName, tc.namespace, tc.backend, tc.fakedAverage)
 			_, err = newDeployment(client, tc.namespace, tc.backend, tc.replicas, tc.readyReplicas)
 			require.NoError(t, err)
 			collector, err := NewSkipperCollector(client, plugin, hpa, config, time.Minute, tc.backendAnnotations, tc.backend)
@@ -341,6 +342,7 @@ func TestSkipperCollector(t *testing.T) {
 			if tc.expectError {
 				require.Error(t, err)
 			} else {
+				require.NoError(t, err)
 				require.Equal(t, map[string]string{"query": tc.expectedQuery}, plugin.config)
 				require.NoError(t, err, "failed to collect metrics: %v", err)
 				require.Len(t, collected, 1, "the number of metrics returned is not 1")
@@ -350,7 +352,7 @@ func TestSkipperCollector(t *testing.T) {
 	}
 }
 
-func makeIngress(client kubernetes.Interface, namespace, ingressName, backend string, hostnames []string, backendWeights map[string]map[string]int) error {
+func makeIngress(client kubernetes.Interface, namespace, ingressName, backend string, hostnames []string, backendWeights map[string]map[string]float64) error {
 	annotations := make(map[string]string)
 	for anno, weights := range backendWeights {
 		sWeights, err := json.Marshal(weights)
@@ -381,12 +383,13 @@ func makeIngress(client kubernetes.Interface, namespace, ingressName, backend st
 			Host: hostname,
 		})
 	}
-	_, err := client.ExtensionsV1beta1().Ingresses(namespace).Create(ingress)
+	_, err := client.NetworkingV1beta1().Ingresses(namespace).Create(context.TODO(), ingress, metav1.CreateOptions{})
 	return err
 }
 
-func makeHPA(ingressName, backend string) *autoscalingv2.HorizontalPodAutoscaler {
+func makeHPA(namespace, ingressName, backend string) *autoscalingv2.HorizontalPodAutoscaler {
 	return &autoscalingv2.HorizontalPodAutoscaler{
+		ObjectMeta: metav1.ObjectMeta{Namespace: namespace},
 		Spec: autoscalingv2.HorizontalPodAutoscalerSpec{
 			ScaleTargetRef: autoscalingv2.CrossVersionObjectReference{
 				Kind: "Deployment",
@@ -404,9 +407,13 @@ func makeHPA(ingressName, backend string) *autoscalingv2.HorizontalPodAutoscaler
 		},
 	}
 }
-func makeConfig(backend string, fakedAverage bool) *MetricConfig {
+func makeConfig(ingressName, namespace, backend string, fakedAverage bool) *MetricConfig {
 	config := &MetricConfig{
 		MetricTypeName: MetricTypeName{Metric: autoscalingv2.MetricIdentifier{Name: fmt.Sprintf("%s,%s", rpsMetricName, backend)}},
+		ObjectReference: custom_metrics.ObjectReference{
+			Name:      ingressName,
+			Namespace: namespace,
+		},
 		MetricSpec: autoscalingv2.MetricSpec{
 			Object: &autoscalingv2.ObjectMetricSource{
 				Target: autoscalingv2.MetricTarget{},

pkg/provider/conversion.go

@@ -1,247 +0,0 @@
-package provider
-
-import (
-	autoscalingv2beta1 "k8s.io/api/autoscaling/v2beta1"
-	autoscaling "k8s.io/api/autoscaling/v2beta2"
-	core "k8s.io/api/core/v1"
-	v1 "k8s.io/api/core/v1"
-	"k8s.io/apimachinery/pkg/conversion"
-)
-
-// from: https://github.com/kubernetes/kubernetes/blob/v1.14.4/pkg/apis/autoscaling/v2beta1/conversion.go
-
-func Convert_autoscaling_MetricTarget_To_v2beta1_CrossVersionObjectReference(in *autoscaling.MetricTarget, out *autoscalingv2beta1.CrossVersionObjectReference, s conversion.Scope) error {
-	return nil
-}
-
-func Convert_v2beta1_CrossVersionObjectReference_To_autoscaling_MetricTarget(in *autoscalingv2beta1.CrossVersionObjectReference, out *autoscaling.MetricTarget, s conversion.Scope) error {
-	return nil
-}
-
-func Convert_v2beta1_ResourceMetricStatus_To_autoscaling_ResourceMetricStatus(in *autoscalingv2beta1.ResourceMetricStatus, out *autoscaling.ResourceMetricStatus, s conversion.Scope) error {
-	out.Name = core.ResourceName(in.Name)
-	utilization := in.CurrentAverageUtilization
-	averageValue := in.CurrentAverageValue
-	out.Current = autoscaling.MetricValueStatus{
-		AverageValue:       &averageValue,
-		AverageUtilization: utilization,
-	}
-	return nil
-}
-
-func Convert_autoscaling_ResourceMetricStatus_To_v2beta1_ResourceMetricStatus(in *autoscaling.ResourceMetricStatus, out *autoscalingv2beta1.ResourceMetricStatus, s conversion.Scope) error {
-	out.Name = v1.ResourceName(in.Name)
-	out.CurrentAverageUtilization = in.Current.AverageUtilization
-	if in.Current.AverageValue != nil {
-		out.CurrentAverageValue = *in.Current.AverageValue
-	}
-	return nil
-}
-
-func Convert_v2beta1_ResourceMetricSource_To_autoscaling_ResourceMetricSource(in *autoscalingv2beta1.ResourceMetricSource, out *autoscaling.ResourceMetricSource, s conversion.Scope) error {
-	out.Name = core.ResourceName(in.Name)
-	utilization := in.TargetAverageUtilization
-	averageValue := in.TargetAverageValue
-
-	var metricType autoscaling.MetricTargetType
-	if utilization == nil {
-		metricType = autoscaling.AverageValueMetricType
-	} else {
-		metricType = autoscaling.UtilizationMetricType
-	}
-	out.Target = autoscaling.MetricTarget{
-		Type:               metricType,
-		AverageValue:       averageValue,
-		AverageUtilization: utilization,
-	}
-	return nil
-}
-
-func Convert_autoscaling_ResourceMetricSource_To_v2beta1_ResourceMetricSource(in *autoscaling.ResourceMetricSource, out *autoscalingv2beta1.ResourceMetricSource, s conversion.Scope) error {
-	out.Name = v1.ResourceName(in.Name)
-	out.TargetAverageUtilization = in.Target.AverageUtilization
-	out.TargetAverageValue = in.Target.AverageValue
-	return nil
-}
-
-func Convert_autoscaling_ExternalMetricSource_To_v2beta1_ExternalMetricSource(in *autoscaling.ExternalMetricSource, out *autoscalingv2beta1.ExternalMetricSource, s conversion.Scope) error {
-	out.MetricName = in.Metric.Name
-	out.TargetValue = in.Target.Value
-	out.TargetAverageValue = in.Target.AverageValue
-	out.MetricSelector = in.Metric.Selector
-	return nil
-}
-
-func Convert_v2beta1_ExternalMetricSource_To_autoscaling_ExternalMetricSource(in *autoscalingv2beta1.ExternalMetricSource, out *autoscaling.ExternalMetricSource, s conversion.Scope) error {
-	value := in.TargetValue
-	averageValue := in.TargetAverageValue
-
-	var metricType autoscaling.MetricTargetType
-	if value == nil {
-		metricType = autoscaling.AverageValueMetricType
-	} else {
-		metricType = autoscaling.ValueMetricType
-	}
-
-	out.Target = autoscaling.MetricTarget{
-		Type:         metricType,
-		Value:        value,
-		AverageValue: averageValue,
-	}
-
-	out.Metric = autoscaling.MetricIdentifier{
-		Name:     in.MetricName,
-		Selector: in.MetricSelector,
-	}
-	return nil
-}
-
-func Convert_autoscaling_ObjectMetricSource_To_v2beta1_ObjectMetricSource(in *autoscaling.ObjectMetricSource, out *autoscalingv2beta1.ObjectMetricSource, s conversion.Scope) error {
-	if in.Target.Value != nil {
-		out.TargetValue = *in.Target.Value
-	}
-	out.AverageValue = in.Target.AverageValue
-
-	out.Target = autoscalingv2beta1.CrossVersionObjectReference{
-		Kind:       in.DescribedObject.Kind,
-		Name:       in.DescribedObject.Name,
-		APIVersion: in.DescribedObject.APIVersion,
-	}
-	out.MetricName = in.Metric.Name
-	out.Selector = in.Metric.Selector
-
-	return nil
-}
-
-func Convert_v2beta1_ObjectMetricSource_To_autoscaling_ObjectMetricSource(in *autoscalingv2beta1.ObjectMetricSource, out *autoscaling.ObjectMetricSource, s conversion.Scope) error {
-	var metricType autoscaling.MetricTargetType
-	if in.AverageValue == nil {
-		metricType = autoscaling.ValueMetricType
-	} else {
-		metricType = autoscaling.AverageValueMetricType
-	}
-	out.Target = autoscaling.MetricTarget{
-		Type:         metricType,
-		Value:        &in.TargetValue,
-		AverageValue: in.AverageValue,
-	}
-	out.DescribedObject = autoscaling.CrossVersionObjectReference{
-		Kind:       in.Target.Kind,
-		Name:       in.Target.Name,
-		APIVersion: in.Target.APIVersion,
-	}
-	out.Metric = autoscaling.MetricIdentifier{
-		Name:     in.MetricName,
-		Selector: in.Selector,
-	}
-	return nil
-}
-
-func Convert_autoscaling_PodsMetricSource_To_v2beta1_PodsMetricSource(in *autoscaling.PodsMetricSource, out *autoscalingv2beta1.PodsMetricSource, s conversion.Scope) error {
-	if in.Target.AverageValue != nil {
-		targetAverageValue := *in.Target.AverageValue
-		out.TargetAverageValue = targetAverageValue
-	}
-
-	out.MetricName = in.Metric.Name
-	out.Selector = in.Metric.Selector
-
-	return nil
-}
-
-func Convert_v2beta1_PodsMetricSource_To_autoscaling_PodsMetricSource(in *autoscalingv2beta1.PodsMetricSource, out *autoscaling.PodsMetricSource, s conversion.Scope) error {
-	targetAverageValue := &in.TargetAverageValue
-	var metricType autoscaling.MetricTargetType
-	metricType = autoscaling.AverageValueMetricType
-
-	out.Target = autoscaling.MetricTarget{
-		Type:         metricType,
-		AverageValue: targetAverageValue,
-	}
-	out.Metric = autoscaling.MetricIdentifier{
-		Name:     in.MetricName,
-		Selector: in.Selector,
-	}
-	return nil
-}
-
-func Convert_autoscaling_ExternalMetricStatus_To_v2beta1_ExternalMetricStatus(in *autoscaling.ExternalMetricStatus, out *autoscalingv2beta1.ExternalMetricStatus, s conversion.Scope) error {
-	if &in.Current.AverageValue != nil {
-		out.CurrentAverageValue = in.Current.AverageValue
-	}
-	out.MetricName = in.Metric.Name
-	if in.Current.Value != nil {
-		out.CurrentValue = *in.Current.Value
-	}
-	out.MetricSelector = in.Metric.Selector
-	return nil
-}
-
-func Convert_v2beta1_ExternalMetricStatus_To_autoscaling_ExternalMetricStatus(in *autoscalingv2beta1.ExternalMetricStatus, out *autoscaling.ExternalMetricStatus, s conversion.Scope) error {
-	value := in.CurrentValue
-	averageValue := in.CurrentAverageValue
-	out.Current = autoscaling.MetricValueStatus{
-		Value:        &value,
-		AverageValue: averageValue,
-	}
-	out.Metric = autoscaling.MetricIdentifier{
-		Name:     in.MetricName,
-		Selector: in.MetricSelector,
-	}
-	return nil
-}
-
-func Convert_autoscaling_ObjectMetricStatus_To_v2beta1_ObjectMetricStatus(in *autoscaling.ObjectMetricStatus, out *autoscalingv2beta1.ObjectMetricStatus, s conversion.Scope) error {
-	if in.Current.Value != nil {
-		out.CurrentValue = *in.Current.Value
-	}
-	out.Target = autoscalingv2beta1.CrossVersionObjectReference{
-		Kind:       in.DescribedObject.Kind,
-		Name:       in.DescribedObject.Name,
-		APIVersion: in.DescribedObject.APIVersion,
-	}
-	out.MetricName = in.Metric.Name
-	out.Selector = in.Metric.Selector
-	if in.Current.AverageValue != nil {
-		currentAverageValue := *in.Current.AverageValue
-		out.AverageValue = &currentAverageValue
-	}
-	return nil
-}
-
-func Convert_v2beta1_ObjectMetricStatus_To_autoscaling_ObjectMetricStatus(in *autoscalingv2beta1.ObjectMetricStatus, out *autoscaling.ObjectMetricStatus, s conversion.Scope) error {
-	out.Current = autoscaling.MetricValueStatus{
-		Value:        &in.CurrentValue,
-		AverageValue: in.AverageValue,
-	}
-	out.DescribedObject = autoscaling.CrossVersionObjectReference{
-		Kind:       in.Target.Kind,
-		Name:       in.Target.Name,
-		APIVersion: in.Target.APIVersion,
-	}
-	out.Metric = autoscaling.MetricIdentifier{
-		Name:     in.MetricName,
-		Selector: in.Selector,
-	}
-	return nil
-}
-
-func Convert_autoscaling_PodsMetricStatus_To_v2beta1_PodsMetricStatus(in *autoscaling.PodsMetricStatus, out *autoscalingv2beta1.PodsMetricStatus, s conversion.Scope) error {
-	if in.Current.AverageValue != nil {
-		out.CurrentAverageValue = *in.Current.AverageValue
-	}
-	out.MetricName = in.Metric.Name
-	out.Selector = in.Metric.Selector
-	return nil
-}
-
-func Convert_v2beta1_PodsMetricStatus_To_autoscaling_PodsMetricStatus(in *autoscalingv2beta1.PodsMetricStatus, out *autoscaling.PodsMetricStatus, s conversion.Scope) error {
-	out.Current = autoscaling.MetricValueStatus{
-		AverageValue: &in.CurrentAverageValue,
-	}
-	out.Metric = autoscaling.MetricIdentifier{
-		Name:     in.MetricName,
-		Selector: in.Selector,
-	}
-	return nil
-}