Namespace external metrics (#259)

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

.github/workflows/ci.yaml

@@ -0,0 +1,25 @@
+name: ci
+on: [push, pull_request]
+env:
+  GO111MODULE: on
+jobs:
+  tests:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-go@v2
+      with:
+        go-version: '^1.16'
+    - run: go version
+    - run: go get github.com/mattn/goveralls
+      env:
+        GO111MODULE: off
+    - run: curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | sh -s -- -b $(go env GOPATH)/bin ${GOLANGCI_RELEASE}
+      env:
+        GOLANGCI_RELEASE: v1.37.0
+    - run: make build.docker
+    - run: make test
+    - run: make check
+    - run: goveralls -coverprofile=profile.cov -service=github
+      env:
+        COVERALLS_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.gitignore

@@ -1,4 +1,5 @@
 build/
 apiserver.local.config/
 .idea/
+profile.cov
 vendor/

.travis.yml

@@ -1,20 +0,0 @@
-language: go
-dist: xenial
-
-go:
-  - "1.13.x"
-
-env:
-- GO111MODULE=on GOLANGCI_RELEASE="v1.21.0"
-
-before_install:
-  - GO111MODULE=off go get github.com/mattn/goveralls
-  - GO111MODULE=off go get github.com/lawrencewoodman/roveralls
-  - curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | sh -s -- -b $(go env GOPATH)/bin ${GOLANGCI_RELEASE}
-
-script:
-  - make test
-  - make build.docker
-  - make check
-  - roveralls
-  - goveralls -v -coverprofile=roveralls.coverprofile -service=travis-ci

Dockerfile

@@ -1,5 +1,5 @@
-FROM registry.opensource.zalan.do/stups/alpine:latest
-MAINTAINER Team Teapot @ Zalando SE <team-teapot@zalando.de>
+FROM registry.opensource.zalan.do/library/alpine-3.12:latest
+LABEL maintainer="Team Teapot @ Zalando SE <team-teapot@zalando.de>"
 
 # add binary
 ADD build/linux/kube-metrics-adapter /

MAINTAINERS

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

Makefile

@@ -8,31 +8,45 @@ SOURCES       = $(shell find . -name '*.go')
 DOCKERFILE    ?= Dockerfile
 GOPKGS        = $(shell go list ./...)
 BUILD_FLAGS   ?= -v
+OPENAPI       ?= pkg/api/generated/openapi/zz_generated.openapi.go
 LDFLAGS       ?= -X main.version=$(VERSION) -w -s
 
+
 default: build.local
 
 clean:
 	rm -rf build
+	rm -rf $(OPENAPI)
 
 test:
-	go test -v $(GOPKGS)
+	go test -v -coverprofile=profile.cov $(GOPKGS)
 
 check:
 	go mod download
 	golangci-lint run --timeout=2m ./...
 
+
+$(OPENAPI): go.mod
+	go run k8s.io/kube-openapi/cmd/openapi-gen \
+		--go-header-file hack/boilerplate.go.txt \
+		--logtostderr \
+		-i k8s.io/metrics/pkg/apis/custom_metrics,k8s.io/metrics/pkg/apis/custom_metrics/v1beta1,k8s.io/metrics/pkg/apis/custom_metrics/v1beta2,k8s.io/metrics/pkg/apis/external_metrics,k8s.io/metrics/pkg/apis/external_metrics/v1beta1,k8s.io/metrics/pkg/apis/metrics,k8s.io/metrics/pkg/apis/metrics/v1beta1,k8s.io/apimachinery/pkg/apis/meta/v1,k8s.io/apimachinery/pkg/api/resource,k8s.io/apimachinery/pkg/version,k8s.io/api/core/v1 \
+		-p pkg/api/generated/openapi \
+		-o . \
+		-O zz_generated.openapi \
+		-r /dev/null
+
 build.local: build/$(BINARY)
 build.linux: build/linux/$(BINARY)
 build.osx: build/osx/$(BINARY)
 
-build/$(BINARY): go.mod $(SOURCES)
+build/$(BINARY): go.mod $(SOURCES) $(OPENAPI)
 	CGO_ENABLED=0 go build -o build/$(BINARY) $(BUILD_FLAGS) -ldflags "$(LDFLAGS)" .
 
-build/linux/$(BINARY): go.mod $(SOURCES)
+build/linux/$(BINARY): go.mod $(SOURCES) $(OPENAPI)
 	GOOS=linux GOARCH=amd64 CGO_ENABLED=0 go build $(BUILD_FLAGS) -o build/linux/$(BINARY) -ldflags "$(LDFLAGS)" .
 
-build/osx/$(BINARY): go.mod $(SOURCES)
+build/osx/$(BINARY): go.mod $(SOURCES) $(OPENAPI)
 	GOOS=darwin GOARCH=amd64 CGO_ENABLED=0 go build $(BUILD_FLAGS) -o build/osx/$(BINARY) -ldflags "$(LDFLAGS)" .
 
 build.docker: build.linux

README.md

@@ -10,7 +10,7 @@ It supports scaling based on [Prometheus metrics](https://prometheus.io/), [SQS
 
 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)
+[custom-metrics-apiserver](https://github.com/kubernetes-sigs/custom-metrics-apiserver)
 library.
 
 Here's an example of a `HorizontalPodAutoscaler` resource configured to get
@@ -22,7 +22,7 @@ kind: HorizontalPodAutoscaler
 metadata:
   name: myapp-hpa
   annotations:
-    # metric-config.<metricType>.<metricName>.<collectorName>/<configKey>
+    # metric-config.<metricType>.<metricName>.<collectorType>/<configKey>
     metric-config.pods.requests-per-second.json-path/json-key: "$.http_server.rps"
     metric-config.pods.requests-per-second.json-path/path: /metrics
     metric-config.pods.requests-per-second.json-path/port: "9090"
@@ -104,7 +104,7 @@ kind: HorizontalPodAutoscaler
 metadata:
   name: myapp-hpa
   annotations:
-    # metric-config.<metricType>.<metricName>.<collectorName>/<configKey>
+    # metric-config.<metricType>.<metricName>.<collectorType>/<configKey>
     metric-config.pods.requests-per-second.json-path/json-key: "$.http_server.rps"
     metric-config.pods.requests-per-second.json-path/path: /metrics
     metric-config.pods.requests-per-second.json-path/port: "9090"
@@ -142,7 +142,7 @@ example the following JSON data would be expected:
 ```
 
 The json-path query support depends on the
-[github.com/oliveagle/jsonpath](https://github.com/oliveagle/jsonpath) library.
+[github.com/spyzhov/ajson](https://github.com/spyzhov/ajson) library.
 See the README for possible queries. It's expected that the metric you query
 returns something that can be turned into a `float64`.
 
@@ -155,6 +155,25 @@ 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`.
 
+The `raw-query` configuration option specifies the query params to send along to the endpoint:
+```yaml
+  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/raw-query: "foo=bar&baz=bop"
+```
+will create a URL like this:
+```
+http://<podIP>:9090/metrics?foo=bar&baz=bop
+```
+
+There are also configuration options for custom (connect and request) timeouts when querying pods for metrics:
+```yaml
+metric-config.pods.requests-per-second.json-path/request-timeout: 2s
+metric-config.pods.requests-per-second.json-path/connect-timeout: 500ms
+```
+
+The default for both of the above values is 15 seconds.
+
 ## Prometheus collector
 
 The Prometheus collector is a generic collector which can map Prometheus
@@ -183,15 +202,24 @@ the trade-offs between the two approaches.
 | `prometheus-query` | Generic metric which requires a user defined query. | External | | `>=1.12` |
 | *custom* | No predefined metrics. Metrics are generated from user defined queries. | Object | *any* | `>=1.12` |
 
+### Configure Scrape Interval
+
+There is a way to set the interval via an annotation like:
+
+```yaml
+metric-config.external.prometheus-query.prometheus/interval: 30s
+```
+
+Default is 1 minute.
+
 ### Example: External Metric
 
 This is an example of an HPA configured to get metrics based on a Prometheus
 query. The query is defined in the annotation
-`metric-config.external.prometheus-query.prometheus/processed-events-per-second`
+`metric-config.external.processed-events-per-second.prometheus/query`
 where `processed-events-per-second` is the query name which will be associated
-with the result of the query. A matching `query-name` label must be defined in
-the `matchLabels` of the metric definition. This allows having multiple
-prometheus queries associated with a single HPA.
+with the result of the query.
+This allows having multiple prometheus queries associated with a single HPA.
 
 ```yaml
 apiVersion: autoscaling/v2beta2
@@ -202,10 +230,9 @@ metadata:
     # This annotation is optional.
     # If specified, then this prometheus server is used,
     # instead of the prometheus server specified as the CLI argument `--prometheus-server`.
-    metric-config.external.prometheus-query.prometheus/prometheus-server: http://prometheus.my-namespace.svc
-    # metric-config.<metricType>.<metricName>.<collectorName>/<configKey>
-    # <configKey> == query-name
-    metric-config.external.prometheus-query.prometheus/processed-events-per-second: |
+    metric-config.external.processed-events-per-second.prometheus/prometheus-server: http://prometheus.my-namespace.svc
+    # metric-config.<metricType>.<metricName>.<collectorType>/<configKey>
+    metric-config.external.processed-events-per-second.prometheus/query: |
       scalar(sum(rate(event-service_events_count{application="event-service",processed="true"}[1m])))
 spec:
   scaleTargetRef:
@@ -218,10 +245,10 @@ spec:
   - type: External
     external:
       metric:
-        name: prometheus-query
+        name: processed-events-per-second
         selector:
           matchLabels:
-            query-name: processed-events-per-second
+            type: prometheus
       target:
         type: AverageValue
         averageValue: "10"
@@ -252,7 +279,7 @@ kind: HorizontalPodAutoscaler
 metadata:
   name: myapp-hpa
   annotations:
-    # metric-config.<metricType>.<metricName>.<collectorName>/<configKey>
+    # metric-config.<metricType>.<metricName>.<collectorType>/<configKey>
     metric-config.object.processed-events-per-second.prometheus/query: |
       scalar(sum(rate(event-service_events_count{application="event-service",processed="true"}[1m])))
     metric-config.object.processed-events-per-second.prometheus/per-replica: "true"
@@ -353,10 +380,9 @@ we only support Flux instead of InfluxQL.
 
 This is an example of an HPA configured to get metrics based on a Flux query.
 The query is defined in the annotation
-`metric-config.external.flux-query.influxdb/queue_depth`
-where `queue_depth` is the query name which will be associated with the result of the query.
-A matching `query-name` label must be defined in the `matchLabels` of the metric definition.
-This allows having multiple flux queries associated with a single HPA.
+`metric-config.external.<metricName>.influxdb/query` where `<metricName>` is
+the query name which will be associated with the result of the query.  This
+allows having multiple flux queries associated with a single HPA.
 
 ```yaml
 apiVersion: autoscaling/v2beta2
@@ -369,13 +395,14 @@ metadata:
     # instead of using the ones specified via CLI. Respectively:
     #  - --influxdb-address
     #  - --influxdb-token
-    #  - --influxdb-org-id
-    metric-config.external.flux-query.influxdb/address: "http://influxdbv2.my-namespace.svc"
-    metric-config.external.flux-query.influxdb/token: "secret-token"
-    metric-config.external.flux-query.influxdb/org-id: "deadbeef"
-    # metric-config.<metricType>.<metricName>.<collectorName>/<configKey>
+    #  - --influxdb-org
+    metric-config.external.queue-depth.influxdb/address: "http://influxdbv2.my-namespace.svc"
+    metric-config.external.queue-depth.influxdb/token: "secret-token"
+    # This could be either the organization name or the ID.
+    metric-config.external.queue-depth.influxdb/org: "deadbeef"
+    # metric-config.<metricType>.<metricName>.<collectorType>/<configKey>
     # <configKey> == query-name
-    metric-config.external.flux-query.influxdb/queue_depth: |
+    metric-config.external.queue-depth.influxdb/query: |
         from(bucket: "apps")
           |> range(start: -30s)
           |> filter(fn: (r) => r._measurement == "queue_depth")
@@ -395,10 +422,10 @@ spec:
   - type: External
     external:
       metric:
-        name: flux-query
+        name: queue-depth
         selector:
           matchLabels:
-            query-name: queue_depth
+            type: influxdb
       target:
         type: Value
         value: "1"
@@ -460,9 +487,10 @@ spec:
   - type: External
     external:
       metric:
-        name: sqs-queue-length
+        name: my-sqs
         selector:
           matchLabels:
+            type: sqs-queue-length
             queue-name: foobar
             region: eu-central-1
       target:
@@ -501,9 +529,9 @@ kind: HorizontalPodAutoscaler
 metadata:
   name: myapp-hpa
   annotations:
-    # metric-config.<metricType>.<metricName>.<collectorName>/<configKey>
-    metric-config.external.zmon-check.zmon/key: "custom.*"
-    metric-config.external.zmon-check.zmon/tag-application: "my-custom-app-*"
+    # metric-config.<metricType>.<metricName>.<collectorType>/<configKey>
+    metric-config.external.my-zmon-check.zmon/key: "custom.*"
+    metric-config.external.my-zmon-check.zmon/tag-application: "my-custom-app-*"
 spec:
   scaleTargetRef:
     apiVersion: apps/v1
@@ -515,17 +543,18 @@ spec:
   - type: External
     external:
       metric:
-          name: zmon-check
+          name: my-zmon-check
           selector:
             matchLabels:
+              type: zmon
               check-id: "1234" # the ZMON check to query for metrics
               key: "custom.value"
               tag-application: my-custom-app
               aggregators: avg # comma separated list of aggregation functions, default: last
               duration: 5m # default: 10m
-        target:
-          averageValue: "30"
-          type: AverageValue
+      target:
+        averageValue: "30"
+        type: AverageValue
 ```
 
 The `check-id` specifies the ZMON check to query for the metrics. `key`
@@ -567,9 +596,65 @@ specify a duration of `5m` then the query will return metric points for the
 last 5 minutes and apply the specified aggregation with the same duration .e.g
 `max(5m)`.
 
-The annotations `metric-config.external.zmon-check.zmon/key` and
-`metric-config.external.zmon-check.zmon/tag-<name>` can be optionally used if
+The annotations `metric-config.external.my-zmon-check.zmon/key` and
+`metric-config.external.my-zmon-check.zmon/tag-<name>` can be optionally used if
 you need to define a `key` or other `tag` with a "star" query syntax like
 `values.*`. This *hack* is in place because it's not allowed to use `*` in the
 metric label definitions. If both annotations and corresponding label is
 defined, then the annotation takes precedence.
+
+## HTTP Collector
+
+The http collector allows collecting metrics from an external endpoint specified in the HPA.
+Currently only `json-path` collection is supported.
+
+### Supported metrics
+
+| Metric | Description | Type | K8s Versions |
+| ------------ | -------------- | ------- | -- |
+| *custom* | No predefined metrics. Metrics are generated from user defined queries. | Pods | `>=1.12` |
+
+### Example
+
+This is an example of using the HTTP collector to collect metrics from a json
+metrics endpoint specified in the annotations.
+
+```yaml
+apiVersion: autoscaling/v2beta2
+kind: HorizontalPodAutoscaler
+metadata:
+  name: myapp-hpa
+  annotations:
+    # metric-config.<metricType>.<metricName>.<collectorType>/<configKey>
+    metric-config.external.unique-metric-name.json-path/json-key: "$.some-metric.value"
+    metric-config.external.unique-metric-name.json-path/endpoint: "http://metric-source.app-namespace:8080/metrics"
+    metric-config.external.unique-metric-name.json-path/aggregator: "max"
+spec:
+  scaleTargetRef:
+    apiVersion: apps/v1
+    kind: Deployment
+    name: myapp
+  minReplicas: 1
+  maxReplicas: 10
+  metrics:
+  - type: External
+    external:
+      metric:
+        name: unique-metric-name
+        selector:
+          matchLabels:
+            type: json-path
+      target:
+        averageValue: 1
+        type: AverageValue
+```
+
+The HTTP collector similar to the Pod Metrics collector. The metric name should always be `http`.
+This value is also used in the annotations to configure the metrics adapter to query the required
+target. The following configuration values are supported:
+
+- `json-key` to specify the JSON path of the metric to be queried
+- `endpoint` the fully formed path to query for the metric. In the above example a Kubernetes _Service_
+    in the namespace `app-namespace` is called.
+- `aggregator` is only required if the metric is an array of values and specifies how the values
+    are aggregated. Currently this option can support the values: `sum`, `max`, `min`, `avg`.

docs/helm/Chart.yaml

@@ -0,0 +1,9 @@
+apiVersion: v2
+name: kube-metrics-adapter
+version: 0.1.9
+description: kube-metrics-adapter helm chart
+home: https://github.com/zalando-incubator/kube-metrics-adapter
+maintainers:
+  - name: The Zalando Incubator
+    email: opensource@zalando.de
+    url: https://github.com/zalando-incubator

docs/helm/templates/custom-metrics-apiservice.yaml

@@ -0,0 +1,15 @@
+{{- if .Values.enableCustomMetricsApi }}
+apiVersion: apiregistration.k8s.io/v1beta1
+kind: APIService
+metadata:
+  name: v1beta1.custom.metrics.k8s.io
+spec:
+  service:
+    name: kube-metrics-adapter
+    namespace: {{ .Values.namespace }}
+  group: custom.metrics.k8s.io
+  version: v1beta1
+  insecureSkipTLSVerify: {{ .Values.tls.skipTLSVerify }}
+  groupPriorityMinimum: 100
+  versionPriority: 100
+{{- end}}

docs/helm/templates/deployment.yaml

@@ -0,0 +1,191 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: kube-metrics-adapter
+  namespace: {{ .Values.namespace }}
+  labels:
+    application: kube-metrics-adapter
+    version: {{ .Values.registry.imageTag }}
+spec:
+  replicas: {{ .Values.replicas }}
+  selector:
+    matchLabels:
+      application: kube-metrics-adapter
+  template:
+    metadata:
+      labels:
+        application: kube-metrics-adapter
+        version: {{ .Values.registry.imageTag }}
+    spec:
+      serviceAccountName: kube-metrics-adapter
+      containers:
+        - name: kube-metrics-adapter
+          image: {{ .Values.registry.image}}:{{ .Values.registry.imageTag }}
+          args:
+            {{- if .Values.addDirectoryHeader }}
+            - --add_dir_header={{ .Values.addDirectoryHeader }}
+            {{- end}}
+            {{- if .Values.log.alsoToStderr }}
+            - --alsologtostderr={{ .Values.log.alsoToStderr }}
+            {{- end}}
+            {{- if .Values.authentication.kubeConfig }}
+            - --authentication-kubeconfig={{ .Values.authentication.kubeConfig }}
+            {{- end}}
+            {{- if .Values.authentication.skipLookup }}
+            - --authentication-skip-lookup={{ .Values.authentication.skipLookup }}
+            {{- end}}
+            {{- if .Values.authentication.tokenWebhookCacheTtl }}
+            - --authentication-token-webhook-cache-ttl={{ .Values.authentication.tokenWebhookCacheTtl }}
+            {{- end}}
+            {{- if .Values.authentication.tolerateLookupFailure }}
+            - --authentication-tolerate-lookup-failure={{ .Values.authentication.tolerateLookupFailure }}
+            {{- end}}
+            {{- if .Values.authorization.alwaysAllowPaths }}
+            - --authorization-always-allow-paths={{ .Values.authorization.alwaysAllowPaths }}
+            {{- end}}
+            {{- if .Values.authorization.kubeConfig }}
+            - --authorization-kubeconfig={{ .Values.authorization.kubeConfig }}
+            {{- end}}
+            {{- if .Values.authorization.webhookCache.authorizedTtl }}
+            - --authorization-webhook-cache-authorized-ttl={{ .Values.authorization.webhookCache.authorizedTtl }}
+            {{- end}}
+            {{- if .Values.authorization.webhookCache.unauthorizedTtl }}
+            - --authorization-webhook-cache-unauthorized-ttl={{ .Values.authorization.webhookCache.unauthorizedTtl }}
+            {{- end}}
+            {{- if .Values.aws.externalMetrics }}
+            - --aws-external-metrics={{ .Values.aws.externalMetrics }}
+            {{- end}}
+            {{- if .Values.aws.region }}
+            - --aws-region={{ .Values.aws.region }}
+            {{- end}}
+            {{- if .Values.tls.certificateDirectory }}
+            - --cert-dir={{ .Values.tls.certificateDirectory }}
+            {{- end}}
+            {{- if .Values.tls.clientCaFile }}
+            - --client-ca-file={{ .Values.tls.clientCaFile }}
+            {{- end}}
+            {{- if .Values.contentionProfiling }}
+            - --contention-profiling={{ .Values.contentionProfiling }}
+            {{- end}}
+            {{- if .Values.credentialsDirectory }}
+            - --credentials-dir={{ .Values.credentialsDirectory }}
+            {{- end}}
+            {{- if .Values.disregardIncompatibleHPAs }}
+            - --disregard-incompatible-hpas={{ .Values.disregardIncompatibleHPAs }}
+            {{- end}}
+            {{- if .Values.enableCustomMetricsApi }}
+            - --enable-custom-metrics-api={{ .Values.enableCustomMetricsApi }}
+            {{- end}}
+            {{- if .Values.enableExternalMetricsApi }}
+            - --enable-external-metrics-api={{ .Values.enableExternalMetricsApi }}
+            {{- end}}
+            {{- if .Values.http2MaxStreamsPerConnection }}
+            - --http2-max-streams-per-connection={{ .Values.http2MaxStreamsPerConnection }}
+            {{- end}}
+            {{- if .Values.influxDB.address }}
+            - --influxdb-address={{ .Values.influxDB.address }}
+            {{- end}}
+            {{- if .Values.influxDB.organization }}
+            - --influxdb-org={{ .Values.influxDB.organization }}
+            {{- end}}
+            {{- if .Values.influxDB.token }}
+            - --influxdb-token={{ .Values.influxDB.token }}
+            {{- end}}
+            {{- if .Values.listerKubeConfig }}
+            - --lister-kubeconfig={{ .Values.listerKubeConfig }}
+            {{- end}}
+            {{- if .Values.log.flushFrequency }}
+            - --log-flush-frequency={{ .Values.log.flushFrequency }}
+            {{- end}}
+            {{- if .Values.log.backtraceAtTraceLocation }}
+            - --log_backtrace_at={{ .Values.log.backtraceAtTraceLocation }}
+            {{- end}}
+            {{- if .Values.log.directory }}
+            - --log_dir={{ .Values.log.directory }}
+            {{- end}}
+            {{- if .Values.log.file }}
+            - --log_file={{ .Values.log.file }}
+            {{- end}}
+            {{- if .Values.log.fileMaxSize }}
+            - --log_file_max_size={{ .Values.log.fileMaxSize }}
+            {{- end}}
+            {{- if .Values.log.toStderr }}
+            - --logtostderr={{ .Values.log.toStderr }}
+            {{- end}}
+            {{- if .Values.prometheus.metricsAddress }}
+            - --metrics-address={{ .Values.prometheus.metricsAddress }}
+            {{- end}}
+            {{- if .Values.profiling }}
+            - --profiling={{ .Values.profiling }}
+            {{- end}}
+            {{- if .Values.prometheus.server }}
+            - --prometheus-server={{ .Values.prometheus.server }}
+            {{- end}}
+            {{- if .Values.requestHeader.allowedNames }}
+            - --requestheader-allowed-names={{ .Values.requestHeader.allowedNames }}
+            {{- end}}
+            {{- if .Values.requestHeader.clientCaFile }}
+            - --requestheader-client-ca-file={{ .Values.requestHeader.clientCaFile }}
+            {{- end}}
+            {{- if .Values.requestHeader.extraHeadersPrefix }}
+            - --requestheader-extra-headers-prefix={{ .Values.requestHeader.extraHeadersPrefix }}
+            {{- end}}
+            {{- if .Values.requestHeader.groupHeaders }}
+            - --requestheader-group-headers={{ .Values.requestHeader.groupHeaders }}
+            {{- end}}
+            {{- if .Values.requestHeader.usernameHeaders }}
+            - --requestheader-username-headers={{ .Values.requestHeader.usernameHeaders }}
+            {{- end}}
+            - --secure-port={{ .Values.service.internalPort }}
+            {{- if .Values.log.skipHeaders }}
+            - --skip_headers={{ .Values.log.skipHeaders }}
+            {{- end}}
+            {{- if .Values.log.skipLogHeaders }}
+            - --skip_log_headers={{ .Values.log.skipLogHeaders }}
+            {{- end}}
+            {{- if .Values.skipperBackendsAnnotation }}
+            - --skipper-backends-annotation={{ .Values.skipperBackendsAnnotation }}
+            {{- end}}
+            {{- if .Values.skipperIngressMetrics }}
+            - --skipper-ingress-metrics={{ .Values.skipperIngressMetrics }}
+            {{- end}}
+            {{- if .Values.log.stderrThreshold }}
+            - --stderrthreshold={{ .Values.log.stderrThreshold }}
+            {{- end}}
+            {{- if .Values.tls.certFile }}
+            - --tls-cert-file={{ .Values.tls.certFile }}
+            {{- end}}
+            {{- if .Values.tls.cipherSuites }}
+            - --tls-cipher-suites={{ .Values.tls.cipherSuites }}
+            {{- end}}
+            {{- if .Values.tls.minVersion }}
+            - --tls-min-version={{ .Values.tls.minVersion }}
+            {{- end}}
+            {{- if .Values.tls.privateKeyFile }}
+            - --tls-private-key-file={{ .Values.tls.privateKeyFile }}
+            {{- end}}
+            {{- if .Values.tls.sniCertKey }}
+            - --tls-sni-cert-key={{ .Values.tls.sniCertKey }}
+            {{- end}}
+            {{- if .Values.token }}
+            - --token={{ .Values.token }}
+            {{- end}}
+            {{- if .Values.log.level }}
+            - --v={{ .Values.log.level }}
+            {{- end}}
+            {{- if .Values.vmodule }}
+            - --vmodule={{ .Values.vmodule }}
+            {{- end}}
+            {{- if .Values.zmon.kariosdbEndpoint }}
+            - --zmon-kariosdb-endpoint={{ .Values.zmon.kariosdbEndpoint }}
+            {{- end}}
+            {{- if .Values.zmon.tokenName }}
+            - --zmon-token-name={{ .Values.zmon.tokenName }}
+            {{- end}}
+          resources:
+            limits:
+              cpu: {{ .Values.resources.limits.cpu }}
+              memory: {{ .Values.resources.limits.memory }}
+            requests:
+              cpu: {{ .Values.resources.requests.cpu }}
+              memory: {{ .Values.resources.requests.memory }}

docs/helm/templates/external-metrics-apiservice.yaml

@@ -0,0 +1,15 @@
+{{- if .Values.enableExternalMetricsApi }}
+apiVersion: apiregistration.k8s.io/v1beta1
+kind: APIService
+metadata:
+  name: v1beta1.external.metrics.k8s.io
+spec:
+  service:
+    name: kube-metrics-adapter
+    namespace: {{ .Values.namespace }}
+  group: external.metrics.k8s.io
+  version: v1beta1
+  insecureSkipTLSVerify: {{ .Values.tls.skipTLSVerify }}
+  groupPriorityMinimum: 100
+  versionPriority: 100
+{{- end}}

docs/helm/templates/rbac.yaml

@@ -0,0 +1,154 @@
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: kube-metrics-adapter-server-resources
+rules:
+- apiGroups:
+  - custom.metrics.k8s.io
+  resources: ["*"]
+  verbs: ["*"]
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: external-metrics-server-resources
+rules:
+- apiGroups:
+  - external.metrics.k8s.io
+  resources: ["*"]
+  verbs: ["*"]
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: kube-metrics-adapter-resource-reader
+rules:
+- apiGroups:
+  - ""
+  resources:
+  - namespaces
+  - pods
+  - services
+  - configmaps
+  verbs:
+  - get
+  - list
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: kube-metrics-adapter-resource-collector
+rules:
+- apiGroups:
+  - ""
+  resources:
+  - events
+  verbs:
+  - create
+  - patch
+- apiGroups:
+  - ""
+  resources:
+  - pods
+  verbs:
+  - list
+- apiGroups:
+  - apps
+  resources:
+  - deployments
+  - statefulsets
+  verbs:
+  - get
+- apiGroups:
+  - extensions
+  resources:
+  - ingresses
+  verbs:
+  - get
+- apiGroups:
+  - autoscaling
+  resources:
+  - horizontalpodautoscalers
+  verbs:
+  - get
+  - list
+  - watch
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: hpa-controller-custom-metrics
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: kube-metrics-adapter-server-resources
+subjects:
+- kind: ServiceAccount
+  name: horizontal-pod-autoscaler
+  namespace: kube-system
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: hpa-controller-external-metrics
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: external-metrics-server-resources
+subjects:
+- kind: ServiceAccount
+  name: horizontal-pod-autoscaler
+  namespace: kube-system
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: RoleBinding
+metadata:
+  name: kube-metrics-adapter-auth-reader
+  namespace: kube-system
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: Role
+  name: extension-apiserver-authentication-reader
+subjects:
+- kind: ServiceAccount
+  name: kube-metrics-adapter
+  namespace: {{ .Values.namespace }}
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: custom-metrics:system:auth-delegator
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: system:auth-delegator
+subjects:
+- kind: ServiceAccount
+  name: kube-metrics-adapter
+  namespace: {{ .Values.namespace }}
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: kube-metrics-adapter-resource-collector
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: kube-metrics-adapter-resource-collector
+subjects:
+- kind: ServiceAccount
+  name: kube-metrics-adapter
+  namespace: {{ .Values.namespace }}
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: kube-metrics-adapter-resource-reader
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: kube-metrics-adapter-resource-reader
+subjects:
+- kind: ServiceAccount
+  name: kube-metrics-adapter
+  namespace: {{ .Values.namespace }}

docs/helm/templates/service-account.yaml

@@ -0,0 +1,5 @@
+kind: ServiceAccount
+apiVersion: v1
+metadata:
+  name: kube-metrics-adapter
+  namespace: {{ .Values.namespace }}

docs/helm/templates/service.yaml

@@ -0,0 +1,11 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: kube-metrics-adapter
+  namespace: {{ .Values.namespace }}
+spec:
+  ports:
+    - port: {{ .Values.service.port }}
+      targetPort: {{ .Values.service.internalPort }}
+  selector:
+    application: kube-metrics-adapter

docs/helm/values.yaml

@@ -0,0 +1,94 @@
+namespace: kube-system
+
+replicas: 1
+
+registry:
+  image: registry.opensource.zalan.do/teapot/kube-metrics-adapter
+  imageTag: v0.1.9
+  imagePullPolicy: IfNotPresent
+
+service:
+  port: 443
+  internalPort: 443
+
+addDirectoryHeader:
+contentionProfiling:
+profiling:
+enableCustomMetricsApi:
+enableExternalMetricsApi:
+credentialsDirectory:
+disregardIncompatibleHPAs:
+http2MaxStreamsPerConnection:
+listerKubeConfig:
+skipperBackendsAnnotation:
+skipperIngressMetrics:
+token:
+vmodule:
+
+authentication:
+  kubeConfig:
+  skipLookup:
+  tokenWebhookCacheTtl:
+  tolerateLookupFailure:
+
+authorization:
+  kubeConfig:
+  alwaysAllowPaths:
+  webhookCache:
+    authorizedTtl:
+    unauthorizedTtl:
+
+aws:
+  externalMetrics:
+  region:
+
+influxDB:
+  address:
+  organization:
+  token:
+
+log:
+  alsoToStderr:
+  toStderr:
+  flushFrequency:
+  backtraceAtTraceLocation:
+  directory:
+  file:
+  fileMaxSize:
+  level:
+  stderrThreshold:
+  skipHeaders:
+  skipLogHeaders:
+
+prometheus:
+  server: http://prometheus.kube-system.svc.cluster.local
+  metricsAddress:
+
+requestHeader:
+  allowedNames:
+  clientCaFile:
+  extraHeadersPrefix:
+  groupHeaders:
+  usernameHeaders:
+
+tls:
+  skipTLSVerify: true
+  certificateDirectory:
+  clientCaFile:
+  certFile:
+  cipherSuites:
+  minVersion:
+  privateKeyFile:
+  sniCertKey:
+
+zmon:
+  kariosdbEndpoint:
+  tokenName:
+
+resources:
+  limits:
+    cpu: 100m
+    memory: 100Mi
+  requests:
+    cpu: 100m
+    memory: 100Mi

example/deploy/hpa.yaml

@@ -6,7 +6,7 @@ metadata:
   labels:
     application: custom-metrics-consumer
   annotations:
-    # metric-config.<metricType>.<metricName>.<collectorName>/<configKey>
+    # metric-config.<metricType>.<metricName>.<collectorType>/<configKey>
     metric-config.pods.queue-length.json-path/json-key: "$.queue.length"
     metric-config.pods.queue-length.json-path/path: /metrics
     metric-config.pods.queue-length.json-path/port: "9090"
@@ -50,9 +50,10 @@ spec:
   - type: External
     external:
       metric:
-        name: sqs-queue-length
+        name: app-queue-length
         selector:
           matchLabels:
+            type: sqs-queue-length
             queue-name: foobar
             region: eu-central-1
       target:

go.mod

@@ -2,31 +2,32 @@ 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/googleapis/gnostic v0.2.0 // indirect
-	github.com/grpc-ecosystem/grpc-gateway v1.4.1 // indirect
-	github.com/influxdata/influxdb-client-go v0.1.4
-	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/aws/aws-sdk-go v1.37.1
+	github.com/go-openapi/spec v0.20.2
+	github.com/influxdata/influxdb-client-go v0.2.0
+	github.com/influxdata/line-protocol v0.0.0-20201012155213-5f565037cbc9 // indirect
+	github.com/kubernetes-sigs/custom-metrics-apiserver v0.0.0-20201216091021-1b9fa998bbaa
+	github.com/mattn/go-colorable v0.1.4 // indirect
+	github.com/mattn/go-isatty v0.0.10 // indirect
+	github.com/onsi/gomega v1.8.1 // indirect
+	github.com/prometheus/client_golang v1.9.0
+	github.com/prometheus/common v0.15.0
+	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 v1.7.0
 	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/crypto v0.0.0-20201124201722-c8d3bf9c5392 // indirect
+	golang.org/x/oauth2 v0.0.0-20200107190931-bf48bf16ab8d
+	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b // indirect
+	k8s.io/api v0.20.0
+	k8s.io/apimachinery v0.20.0
+	k8s.io/apiserver v0.20.0
+	k8s.io/client-go v0.20.0
+	k8s.io/component-base v0.20.0
+	k8s.io/klog v1.0.0
+	k8s.io/kube-openapi v0.0.0-20201113171705-d219536bb9fd
+	k8s.io/metrics v0.20.0
 )
 
-go 1.13
+go 1.15

hack/boilerplate.go.txt

@@ -0,0 +1,16 @@
+/*
+Copyright The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+

hack/tools.go

@@ -0,0 +1,6 @@
+// +build tools
+
+// This package imports things required by build scripts, to force `go mod` to see them as dependencies
+package tools
+
+import _ "k8s.io/kube-openapi/cmd/openapi-gen"

main.go

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

pkg/annotations/parser.go

@@ -15,7 +15,7 @@ const (
 )
 
 type AnnotationConfigs struct {
-	CollectorName string
+	CollectorType string
 	Configs       map[string]string
 	PerReplica    bool
 	Interval      time.Duration
@@ -64,14 +64,14 @@ func (m AnnotationConfigMap) Parse(annotations map[string]string) error {
 		config, ok := m[key]
 		if !ok {
 			config = &AnnotationConfigs{
-				CollectorName: metricCollector,
+				CollectorType: metricCollector,
 				Configs:       map[string]string{},
 			}
 			m[key] = config
 		}
 
 		// TODO: fail if collector name doesn't match
-		if config.CollectorName != metricCollector {
+		if config.CollectorType != metricCollector {
 			continue
 		}
 

pkg/annotations/parser_test.go

@@ -86,6 +86,21 @@ func TestParser(t *testing.T) {
 				"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/aws_collector.go

@@ -33,12 +33,7 @@ func NewAWSCollectorPlugin(sessions map[string]*session.Session) *AWSCollectorPl
 
 // NewCollector initializes a new skipper collector from the specified HPA.
 func (c *AWSCollectorPlugin) NewCollector(hpa *autoscalingv2.HorizontalPodAutoscaler, config *MetricConfig, interval time.Duration) (Collector, error) {
-	switch config.Metric.Name {
-	case AWSSQSQueueLengthMetric:
-		return NewAWSSQSCollector(c.sessions, config, interval)
-	}
-
-	return nil, fmt.Errorf("metric '%s' not supported", config.Metric.Name)
+	return NewAWSSQSCollector(c.sessions, hpa, config, interval)
 }
 
 type AWSSQSCollector struct {
@@ -47,11 +42,12 @@ type AWSSQSCollector struct {
 	region     string
 	queueURL   string
 	queueName  string
+	namespace  string
 	metric     autoscalingv2.MetricIdentifier
 	metricType autoscalingv2.MetricSourceType
 }
 
-func NewAWSSQSCollector(sessions map[string]*session.Session, config *MetricConfig, interval time.Duration) (*AWSSQSCollector, error) {
+func NewAWSSQSCollector(sessions map[string]*session.Session, hpa *autoscalingv2.HorizontalPodAutoscaler, config *MetricConfig, interval time.Duration) (*AWSSQSCollector, error) {
 	if config.Metric.Selector == nil {
 		return nil, fmt.Errorf("selector for queue is not specified")
 	}
@@ -85,6 +81,7 @@ func NewAWSSQSCollector(sessions map[string]*session.Session, config *MetricConf
 		interval:   interval,
 		queueURL:   aws.StringValue(resp.QueueUrl),
 		queueName:  name,
+		namespace:  hpa.Namespace,
 		metric:     config.Metric,
 		metricType: config.Type,
 	}, nil
@@ -108,7 +105,8 @@ func (c *AWSSQSCollector) GetMetrics() ([]CollectedMetric, error) {
 		}
 
 		metricValue := CollectedMetric{
-			Type: c.metricType,
+			Namespace: c.namespace,
+			Type:      c.metricType,
 			External: external_metrics.ExternalMetricValue{
 				MetricName:   c.metric.Name,
 				MetricLabels: c.metric.Selector.MatchLabels,

pkg/collector/collector.go

@@ -4,12 +4,17 @@ import (
 	"fmt"
 	"time"
 
+	log "github.com/sirupsen/logrus"
 	"github.com/zalando-incubator/kube-metrics-adapter/pkg/annotations"
 	autoscalingv2 "k8s.io/api/autoscaling/v2beta2"
 	"k8s.io/metrics/pkg/apis/custom_metrics"
 	"k8s.io/metrics/pkg/apis/external_metrics"
 )
 
+const (
+	typeLabelKey = "type"
+)
+
 type ObjectReference struct {
 	autoscalingv2.CrossVersionObjectReference
 	Namespace string
@@ -19,6 +24,7 @@ type CollectorFactory struct {
 	podsPlugins     pluginMap
 	objectPlugins   objectPluginMap
 	externalPlugins map[string]CollectorPlugin
+	logger          *log.Entry
 }
 
 type objectPluginMap struct {
@@ -39,6 +45,7 @@ func NewCollectorFactory() *CollectorFactory {
 			Named: map[string]*pluginMap{},
 		},
 		externalPlugins: map[string]CollectorPlugin{},
+		logger:          log.WithFields(log.Fields{"collector": "true"}),
 	}
 }
 
@@ -46,6 +53,14 @@ 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
@@ -104,7 +119,7 @@ func (c *CollectorFactory) NewCollector(hpa *autoscalingv2.HorizontalPodAutoscal
 	switch config.Type {
 	case autoscalingv2.PodsMetricSourceType:
 		// first try to find a plugin by format
-		if plugin, ok := c.podsPlugins.Named[config.CollectorName]; ok {
+		if plugin, ok := c.podsPlugins.Named[config.CollectorType]; ok {
 			return plugin.NewCollector(hpa, config, interval)
 		}
 
@@ -115,7 +130,7 @@ func (c *CollectorFactory) NewCollector(hpa *autoscalingv2.HorizontalPodAutoscal
 	case autoscalingv2.ObjectMetricSourceType:
 		// first try to find a plugin by kind
 		if kinds, ok := c.objectPlugins.Named[config.ObjectReference.Kind]; ok {
-			if plugin, ok := kinds.Named[config.CollectorName]; ok {
+			if plugin, ok := kinds.Named[config.CollectorType]; ok {
 				return plugin.NewCollector(hpa, config, interval)
 			}
 
@@ -126,7 +141,7 @@ func (c *CollectorFactory) NewCollector(hpa *autoscalingv2.HorizontalPodAutoscal
 		}
 
 		// else try to find a default plugin for this kind
-		if plugin, ok := c.objectPlugins.Any.Named[config.CollectorName]; ok {
+		if plugin, ok := c.objectPlugins.Any.Named[config.CollectorType]; ok {
 			return plugin.NewCollector(hpa, config, interval)
 		}
 
@@ -134,12 +149,26 @@ func (c *CollectorFactory) NewCollector(hpa *autoscalingv2.HorizontalPodAutoscal
 			return c.objectPlugins.Any.Any.NewCollector(hpa, config, interval)
 		}
 	case autoscalingv2.ExternalMetricSourceType:
-		if plugin, ok := c.externalPlugins[config.Metric.Name]; ok {
+		// First type to get metric type from the `type` label,
+		// otherwise fall back to the legacy metric name based mapping.
+		var pluginKey string
+		if config.Metric.Selector != nil && config.Metric.Selector.MatchLabels != nil {
+			if typ, ok := config.Metric.Selector.MatchLabels[typeLabelKey]; ok {
+				pluginKey = typ
+			}
+		}
+
+		if pluginKey == "" {
+			pluginKey = config.Metric.Name
+			c.logger.Warnf("HPA %s/%s is using deprecated metric type identifier '%s'", hpa.Namespace, hpa.Name, config.Metric.Name)
+		}
+
+		if plugin, ok := c.externalPlugins[pluginKey]; ok {
 			return plugin.NewCollector(hpa, config, interval)
 		}
 	}
 
-	return nil, fmt.Errorf("no plugin found for %s", config.MetricTypeName)
+	return nil, &PluginNotFoundError{metricTypeName: config.MetricTypeName}
 }
 
 type MetricTypeName struct {
@@ -148,9 +177,10 @@ type MetricTypeName struct {
 }
 
 type CollectedMetric struct {
-	Type     autoscalingv2.MetricSourceType
-	Custom   custom_metrics.MetricValue
-	External external_metrics.ExternalMetricValue
+	Type      autoscalingv2.MetricSourceType
+	Namespace string
+	Custom    custom_metrics.MetricValue
+	External  external_metrics.ExternalMetricValue
 }
 
 type Collector interface {
@@ -160,7 +190,7 @@ type Collector interface {
 
 type MetricConfig struct {
 	MetricTypeName
-	CollectorName   string
+	CollectorType   string
 	Config          map[string]string
 	ObjectReference custom_metrics.ObjectReference
 	PerReplica      bool
@@ -220,7 +250,7 @@ func ParseHPAMetrics(hpa *autoscalingv2.HorizontalPodAutoscaler) ([]*MetricConfi
 
 		annotationConfigs, present := parser.GetAnnotationConfig(typeName.Metric.Name, typeName.Type)
 		if present {
-			config.CollectorName = annotationConfigs.CollectorName
+			config.CollectorType = annotationConfigs.CollectorType
 			config.Interval = annotationConfigs.Interval
 			config.PerReplica = annotationConfigs.PerReplica
 			// configs specified in annotations takes precedence

pkg/collector/collector_test.go

@@ -0,0 +1,129 @@
+package collector
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+	autoscalingv2 "k8s.io/api/autoscaling/v2beta2"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+type mockCollectorPlugin struct {
+	Name string
+}
+
+func (c *mockCollectorPlugin) NewCollector(hpa *autoscalingv2.HorizontalPodAutoscaler, config *MetricConfig, interval time.Duration) (Collector, error) {
+	return &mockCollector{Name: c.Name}, nil
+}
+
+type mockCollector struct {
+	Name string
+}
+
+func (c *mockCollector) GetMetrics() ([]CollectedMetric, error) {
+	return nil, nil
+}
+
+func (c *mockCollector) Interval() time.Duration {
+	return 0
+}
+
+func TestNewCollector(t *testing.T) {
+	for _, tc := range []struct {
+		msg               string
+		hpa               *autoscalingv2.HorizontalPodAutoscaler
+		expectedCollector string
+	}{
+		{
+			msg: "should get create collector type from legacy metric name",
+			hpa: &autoscalingv2.HorizontalPodAutoscaler{
+				ObjectMeta: metav1.ObjectMeta{
+					Annotations: map[string]string{},
+				},
+				Spec: autoscalingv2.HorizontalPodAutoscalerSpec{
+					Metrics: []autoscalingv2.MetricSpec{
+						{
+							Type: autoscalingv2.ExternalMetricSourceType,
+							External: &autoscalingv2.ExternalMetricSource{
+								Metric: autoscalingv2.MetricIdentifier{
+									Name: "external-1",
+									Selector: &metav1.LabelSelector{
+										MatchLabels: map[string]string{"x": "y"},
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+			expectedCollector: "external-1",
+		},
+		{
+			msg: "should get create collector type from type label (ignore legacy metric name)",
+			hpa: &autoscalingv2.HorizontalPodAutoscaler{
+				ObjectMeta: metav1.ObjectMeta{
+					Annotations: map[string]string{},
+				},
+				Spec: autoscalingv2.HorizontalPodAutoscalerSpec{
+					Metrics: []autoscalingv2.MetricSpec{
+						{
+							Type: autoscalingv2.ExternalMetricSourceType,
+							External: &autoscalingv2.ExternalMetricSource{
+								Metric: autoscalingv2.MetricIdentifier{
+									Name: "external-1",
+									Selector: &metav1.LabelSelector{
+										MatchLabels: map[string]string{"type": "external-2"},
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+			expectedCollector: "external-2",
+		},
+		{
+			msg: "should not find collector when no collector matches",
+			hpa: &autoscalingv2.HorizontalPodAutoscaler{
+				ObjectMeta: metav1.ObjectMeta{
+					Annotations: map[string]string{},
+				},
+				Spec: autoscalingv2.HorizontalPodAutoscalerSpec{
+					Metrics: []autoscalingv2.MetricSpec{
+						{
+							Type: autoscalingv2.ExternalMetricSourceType,
+							External: &autoscalingv2.ExternalMetricSource{
+								Metric: autoscalingv2.MetricIdentifier{
+									Name: "external-3",
+								},
+							},
+						},
+					},
+				},
+			},
+			expectedCollector: "",
+		},
+	} {
+		t.Run(tc.msg, func(t *testing.T) {
+			collectorFactory := NewCollectorFactory()
+			for _, collector := range []string{"1", "2"} {
+				collectorFactory.RegisterExternalCollector([]string{"external-" + collector}, &mockCollectorPlugin{Name: "external-" + collector})
+			}
+			configs, err := ParseHPAMetrics(tc.hpa)
+			require.NoError(t, err)
+			require.Len(t, configs, 1)
+
+			collector, err := collectorFactory.NewCollector(tc.hpa, configs[0], 0)
+			if tc.expectedCollector == "" {
+				require.Error(t, err)
+			} else {
+				require.NoError(t, err)
+
+				c, ok := collector.(*mockCollector)
+				require.True(t, ok)
+				require.Equal(t, tc.expectedCollector, c.Name)
+			}
+		})
+	}
+}

pkg/collector/http_collector.go

@@ -0,0 +1,108 @@
+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 (
+	HTTPJSONPathType          = "json-path"
+	HTTPMetricNameLegacy      = "http"
+	HTTPEndpointAnnotationKey = "endpoint"
+	HTTPJsonPathAnnotationKey = "json-key"
+	identifierLabel           = "identifier"
+)
+
+type HTTPCollectorPlugin struct{}
+
+func NewHTTPCollectorPlugin() (*HTTPCollectorPlugin, error) {
+	return &HTTPCollectorPlugin{}, nil
+}
+
+func (p *HTTPCollectorPlugin) NewCollector(hpa *v2beta2.HorizontalPodAutoscaler, config *MetricConfig, interval time.Duration) (Collector, error) {
+	collector := &HTTPCollector{
+		namespace: hpa.Namespace,
+	}
+	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
+	namespace     string
+	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{
+		Namespace: c.namespace,
+		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
+}