Basic CRD for scheduled scaling

Signed-off-by: Arjun Naik <arjun.rn@gmail.com>

.github/CODEOWNERS

@@ -0,0 +1,35 @@
+# 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/ISSUE_TEMPLATE.md

@@ -0,0 +1,17 @@
+## Expected Behavior
+
+
+## Actual Behavior
+
+
+## Steps to Reproduce the Problem
+
+  1.
+  1.
+  1.
+
+## Specifications
+
+  - Version:
+  - Platform:
+  - Subsystem:

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,31 @@
+# One-line summary
+
+> Issue : #1234 (only if appropriate)
+
+## Description
+A few sentences describing the overall goals of the pull request's
+commits.
+
+## Types of Changes
+_What types of changes does your code introduce? Keep the ones that apply:_
+
+- New feature (non-breaking change which adds functionality)
+- Bug fix (non-breaking change which fixes an issue)
+- Configuration change
+- Refactor/improvements
+- Documentation / non-code
+
+## Tasks
+_List of tasks you will do to complete the PR_
+  - [ ] Created Task 1
+  - [ ] Created Task 2
+  - [ ] To-do Task 3
+
+## Review
+_List of tasks the reviewer must do to review the PR_
+- [ ] Tests
+- [ ] Documentation
+- [ ] CHANGELOG
+
+## Deployment Notes
+These should highlight any db migrations, feature toggles, etc.

.gitignore

@@ -0,0 +1,4 @@
+build/
+apiserver.local.config/
+.idea/
+vendor/

.golangci.yml

@@ -0,0 +1,19 @@
+run:
+linters-settings:
+  golint:
+      min-confidence: 0.9
+
+linters:
+  disable-all: true
+  enable:
+    - staticcheck
+    - ineffassign
+    - golint
+    - goimports
+    - errcheck
+issues:
+  exclude-rules:
+    # Exclude some staticcheck messages
+    - linters:
+        - staticcheck
+      text: "SA9003:"

.travis.yml

@@ -0,0 +1,20 @@
+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

.zappr.yaml

@@ -0,0 +1,9 @@
+# for github.com
+approvals:
+  groups:
+    zalando:
+      minimum: 2
+      from:
+        orgs:
+          - "zalando"
+X-Zalando-Team: teapot

CODE_OF_CONDUCT.md

@@ -0,0 +1,74 @@
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+In the interest of fostering an open and welcoming environment, we as
+contributors and maintainers pledge to making participation in our project and
+our community a harassment-free experience for everyone, regardless of age, body
+size, disability, ethnicity, gender identity and expression, level of experience,
+nationality, personal appearance, race, religion, or sexual identity and
+orientation.
+
+## Our Standards
+
+Examples of behavior that contributes to creating a positive environment
+include:
+
+* Using welcoming and inclusive language
+* Being respectful of differing viewpoints and experiences
+* Gracefully accepting constructive criticism
+* Focusing on what is best for the community
+* Showing empathy towards other community members
+
+Examples of unacceptable behavior by participants include:
+
+* The use of sexualized language or imagery and unwelcome sexual attention or
+advances
+* Trolling, insulting/derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or electronic
+  address, without explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Our Responsibilities
+
+Project maintainers are responsible for clarifying the standards of acceptable
+behavior and are expected to take appropriate and fair corrective action in
+response to any instances of unacceptable behavior.
+
+Project maintainers have the right and responsibility to remove, edit, or
+reject comments, commits, code, wiki edits, issues, and other contributions
+that are not aligned to this Code of Conduct, or to ban temporarily or
+permanently any contributor for other behaviors that they deem inappropriate,
+threatening, offensive, or harmful.
+
+## Scope
+
+This Code of Conduct applies both within project spaces and in public spaces
+when an individual is representing the project or its community. Examples of
+representing a project or community include using an official project e-mail
+address, posting via an official social media account, or acting as an appointed
+representative at an online or offline event. Representation of a project may be
+further defined and clarified by project maintainers.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported by contacting the project team see [MAINTAINERS.md](MAINTAINERS.md). All
+complaints will be reviewed and investigated and will result in a response that
+is deemed necessary and appropriate to the circumstances. The project team is
+obligated to maintain confidentiality with regard to the reporter of an incident.
+Further details of specific enforcement policies may be posted separately.
+
+Project maintainers who do not follow or enforce the Code of Conduct in good
+faith may face temporary or permanent repercussions as determined by other
+members of the project's leadership.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4,
+available at [http://contributor-covenant.org/version/1/4][version]
+
+[homepage]: http://contributor-covenant.org
+[version]: http://contributor-covenant.org/version/1/4/

CONTRIBUTING.md

@@ -0,0 +1,86 @@
+# Contributing
+
+**Thank you for your interest in making the project better and more useful.
+Your contributions are highly welcome.**
+
+There are multiple ways of getting involved:
+
+- [Report a bug](#report-a-bug)
+- [Suggest a feature](#suggest-a-feature)
+- [Contribute code](#contribute-code)
+
+Below are a few guidelines we would like you to follow.
+If you need help, please reach out to us by opening an issue.
+
+## Report a bug
+
+Reporting bugs is one of the best ways to contribute. Before creating a bug
+report, please check that an [issue](/issues) reporting the same problem does
+not already exist. If there is such an issue, you may add your information as a
+comment.
+
+To report a new bug you should open an issue that summarizes the bug and set
+the label to "bug".
+
+If you want to provide a fix along with your bug report: That is great! In this
+case please send us a pull request as described in section [Contribute
+Code](#contribute-code).
+
+## Suggest a feature
+
+To request a new feature you should open an [issue](../../issues/new) and
+summarize the desired functionality and its use case. Set the issue label to
+"feature".
+
+## Contribute code
+
+This is an outline of what the workflow for code contributions looks like
+
+- Check the list of open [issues](../../issues). Either assign an existing
+  issue to yourself, or create a new one that you would like work on and
+  discuss your ideas and use cases.
+
+It is always best to discuss your plans beforehand, to ensure that your
+contribution is in line with our goals.
+
+- Fork the repository on GitHub
+- Create a topic branch from where you want to base your work. This is usually master.
+- Open a new pull request, label it `work in progress` and outline what you will be contributing
+- Make commits of logical units.
+- Make sure you sign-off on your commits `git commit -s -m "adding X to change Y"`
+- Write good commit messages (see below).
+- Push your changes to a topic branch in your fork of the repository.
+- As you push your changes, update the pull request with new infomation and tasks as you complete them
+- Project maintainers might comment on your work as you progress
+- When you are done, remove the `work in progess` label and ping the maintainers for a review
+- Your pull request must receive a :thumbsup: from two [maintainers](MAINTAINERS)
+
+Thanks for your contributions!
+
+### Commit messages
+
+Your commit messages ideally can answer two questions: what changed and why.
+The subject line should feature the “what” and the body of the commit should
+describe the “why”.
+
+When creating a pull request, its description should reference the corresponding issue id.
+
+### Sign your work / Developer certificate of origin
+All contributions (including pull requests) must agree to the Developer
+Certificate of Origin (DCO) version 1.1. This is exactly the same one created
+and used by the Linux kernel developers and posted on
+http://developercertificate.org/. This is a developer's certification that he
+or she has the right to submit the patch for inclusion into the project. Simply
+submitting a contribution implies this agreement, however, please include a
+"Signed-off-by" tag in every patch (this tag is a conventional way to confirm
+that you agree to the DCO) - you can automate this with a [Git
+hook](https://stackoverflow.com/questions/15015894/git-add-signed-off-by-line-using-format-signoff-not-working)
+
+```
+git commit -s -m "adding X to change Y"
+```
+
+
+
+
+**Have fun, and happy hacking!**

CONTRIBUTORS.md

@@ -0,0 +1,6 @@
+# Project Contributors
+
+All external contributors to the project, we are grateful for all their help 
+
+## Contributors sorted alphabetically
+

Dockerfile

@@ -0,0 +1,7 @@
+FROM registry.opensource.zalan.do/stups/alpine:latest
+MAINTAINER Team Teapot @ Zalando SE <team-teapot@zalando.de>
+
+# add binary
+ADD build/linux/kube-metrics-adapter /
+
+ENTRYPOINT ["/kube-metrics-adapter"]

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2018 Zalando SE
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

MAINTAINERS

@@ -0,0 +1,3 @@
+Mikkel Larsen <mikkel.larsen@zalando.de>
+Arjun Naik <arjun.naik@zalando.de>
+Team Teapot <team-teapot@zalando.de>

Makefile

@@ -0,0 +1,42 @@
+.PHONY: clean test check build.local build.linux build.osx build.docker build.push
+
+BINARY        ?= kube-metrics-adapter
+VERSION       ?= $(shell git describe --tags --always --dirty)
+IMAGE         ?= registry-write.opensource.zalan.do/teapot/$(BINARY)
+TAG           ?= $(VERSION)
+SOURCES       = $(shell find . -name '*.go')
+DOCKERFILE    ?= Dockerfile
+GOPKGS        = $(shell go list ./...)
+BUILD_FLAGS   ?= -v
+LDFLAGS       ?= -X main.version=$(VERSION) -w -s
+
+default: build.local
+
+clean:
+	rm -rf build
+
+test:
+	go test -v $(GOPKGS)
+
+check:
+	go mod download
+	golangci-lint run --timeout=2m ./...
+
+build.local: build/$(BINARY)
+build.linux: build/linux/$(BINARY)
+build.osx: build/osx/$(BINARY)
+
+build/$(BINARY): go.mod $(SOURCES)
+	CGO_ENABLED=0 go build -o build/$(BINARY) $(BUILD_FLAGS) -ldflags "$(LDFLAGS)" .
+
+build/linux/$(BINARY): go.mod $(SOURCES)
+	GOOS=linux GOARCH=amd64 CGO_ENABLED=0 go build $(BUILD_FLAGS) -o build/linux/$(BINARY) -ldflags "$(LDFLAGS)" .
+
+build/osx/$(BINARY): go.mod $(SOURCES)
+	GOOS=darwin GOARCH=amd64 CGO_ENABLED=0 go build $(BUILD_FLAGS) -o build/osx/$(BINARY) -ldflags "$(LDFLAGS)" .
+
+build.docker: build.linux
+	docker build --rm -t "$(IMAGE):$(TAG)" -f $(DOCKERFILE) .
+
+build.push: build.docker
+	docker push "$(IMAGE):$(TAG)"

SECURITY.md

@@ -0,0 +1,8 @@
+We acknowledge that every line of code that we write may potentially contain security issues.
+We are trying to deal with it responsibly and provide patches as quickly as possible.
+
+We host our bug bounty program on HackerOne, it is currently private, therefore if you would like to report a vulnerability and get rewarded for it, please ask to join our program by filling this form:
+
+https://corporate.zalando.com/en/services-and-contact#security-form
+
+You can also send you report via this form if you do not want to join our bug bounty program and just want to report a vulnerability or security issue.

delivery.yaml

@@ -0,0 +1,30 @@
+version: "2017-09-20"
+pipeline:
+- id: build
+  overlay: ci/golang
+  cache:
+    paths:
+    - /go/pkg/mod       # pkg cache for Go modules
+    - ~/.cache/go-build # Go build cache
+  type: script
+  env:
+    GOFLAGS: "-mod=readonly"
+  commands:
+  - desc: test
+    cmd: |
+      make test
+  - desc: build
+    cmd: |
+      make build.docker
+  - desc: push
+    cmd: |
+      if [[ $CDP_TARGET_BRANCH == master && ! $CDP_PULL_REQUEST_NUMBER ]]; then
+        IMAGE=registry-write.opensource.zalan.do/teapot/kube-metrics-adapter
+        VERSION=$(git describe --tags --always)
+      else
+        IMAGE=registry-write.opensource.zalan.do/teapot/kube-metrics-adapter-test
+        VERSION=$CDP_BUILD_VERSION
+      fi
+      IMAGE=$IMAGE VERSION=$VERSION make build.docker
+      git diff --stat --exit-code
+      IMAGE=$IMAGE VERSION=$VERSION make build.push

docs/custom-metrics-apiservice.yaml

@@ -0,0 +1,13 @@
+apiVersion: apiregistration.k8s.io/v1beta1
+kind: APIService
+metadata:
+  name: v1beta1.custom.metrics.k8s.io
+spec:
+  service:
+    name: kube-metrics-adapter
+    namespace: kube-system
+  group: custom.metrics.k8s.io
+  version: v1beta1
+  insecureSkipTLSVerify: true
+  groupPriorityMinimum: 100
+  versionPriority: 100

docs/deployment.yaml

@@ -0,0 +1,40 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: kube-metrics-adapter
+  namespace: kube-system
+  labels:
+    application: kube-metrics-adapter
+    version: latest
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      application: kube-metrics-adapter
+  template:
+    metadata:
+      labels:
+        application: kube-metrics-adapter
+        version: latest
+      annotations:
+        iam.amazonaws.com/role: "kube-aws-test-1-app-zmon"
+    spec:
+      serviceAccountName: custom-metrics-apiserver
+      containers:
+      - name: kube-metrics-adapter
+        image: registry.opensource.zalan.do/teapot/kube-metrics-adapter:latest
+        args:
+        # - --v=9
+        - --prometheus-server=http://prometheus.kube-system.svc.cluster.local
+        - --skipper-ingress-metrics
+        - --aws-external-metrics
+        env:
+        - name: AWS_REGION
+          value: eu-central-1
+        resources:
+          limits:
+            cpu: 100m
+            memory: 100Mi
+          requests:
+            cpu: 100m
+            memory: 100Mi

docs/external-metrics-apiservice.yaml

@@ -0,0 +1,13 @@
+apiVersion: apiregistration.k8s.io/v1beta1
+kind: APIService
+metadata:
+  name: v1beta1.external.metrics.k8s.io
+spec:
+  service:
+    name: kube-metrics-adapter
+    namespace: kube-system
+  group: external.metrics.k8s.io
+  version: v1beta1
+  insecureSkipTLSVerify: true
+  groupPriorityMinimum: 100
+  versionPriority: 100

docs/rbac.yaml

@@ -0,0 +1,146 @@
+kind: ServiceAccount
+apiVersion: v1
+metadata:
+  name: custom-metrics-apiserver
+  namespace: kube-system
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: custom-metrics-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: custom-metrics-resource-reader
+rules:
+- apiGroups:
+  - ""
+  resources:
+  - namespaces
+  - pods
+  - services
+  verbs:
+  - get
+  - list
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: custom-metrics-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: custom-metrics-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: custom-metrics-auth-reader
+  namespace: kube-system
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: Role
+  name: extension-apiserver-authentication-reader
+subjects:
+- kind: ServiceAccount
+  name: custom-metrics-apiserver
+  namespace: kube-system
+---
+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: custom-metrics-apiserver
+  namespace: kube-system
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: custom-metrics-resource-collector
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: custom-metrics-resource-collector
+subjects:
+- kind: ServiceAccount
+  name: custom-metrics-apiserver
+  namespace: kube-system

docs/service.yaml

@@ -0,0 +1,11 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: kube-metrics-adapter
+  namespace: kube-system
+spec:
+  ports:
+  - port: 443
+    targetPort: 443
+  selector:
+    application: kube-metrics-adapter

example/Dockerfile

@@ -0,0 +1,7 @@
+FROM registry.opensource.zalan.do/stups/alpine:latest
+MAINTAINER Team Teapot @ Zalando SE <team-teapot@zalando.de>
+
+# add binary
+ADD build/linux/custom-metrics-consumer /
+
+ENTRYPOINT ["/custom-metrics-consumer"]

example/Makefile

@@ -0,0 +1,42 @@
+.PHONY: clean test check build.local build.linux build.osx build.docker build.push
+
+BINARY        ?= custom-metrics-consumer
+VERSION       ?= $(shell git describe --tags --always --dirty)
+IMAGE         ?= mikkeloscar/$(BINARY)
+TAG           ?= $(VERSION)
+SOURCES       = $(shell find . -name '*.go')
+DOCKERFILE    ?= Dockerfile
+GOPKGS        = $(shell go list ./...)
+BUILD_FLAGS   ?= -v
+LDFLAGS       ?= -X main.version=$(VERSION) -w -s
+
+default: build.local
+
+clean:
+	rm -rf build
+
+test:
+	go test -v $(GOPKGS)
+
+check:
+	golint $(GOPKGS)
+	go vet -v $(GOPKGS)
+
+build.local: build/$(BINARY)
+build.linux: build/linux/$(BINARY)
+build.osx: build/osx/$(BINARY)
+
+build/$(BINARY): $(SOURCES)
+	CGO_ENABLED=0 go build -o build/$(BINARY) $(BUILD_FLAGS) -ldflags "$(LDFLAGS)" .
+
+build/linux/$(BINARY): $(SOURCES)
+	GOOS=linux GOARCH=amd64 CGO_ENABLED=0 go build $(BUILD_FLAGS) -o build/linux/$(BINARY) -ldflags "$(LDFLAGS)" .
+
+build/osx/$(BINARY): $(SOURCES)
+	GOOS=darwin GOARCH=amd64 CGO_ENABLED=0 go build $(BUILD_FLAGS) -o build/osx/$(BINARY) -ldflags "$(LDFLAGS)" .
+
+build.docker: build.linux
+	docker build --rm -t "$(IMAGE):$(TAG)" -f $(DOCKERFILE) .
+
+build.push: build.docker
+	docker push "$(IMAGE):$(TAG)"

example/deploy/deployment.yaml

@@ -0,0 +1,29 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: custom-metrics-consumer
+  labels:
+    application: custom-metrics-consumer
+    version: latest
+spec:
+  selector:
+    matchLabels:
+      application: custom-metrics-consumer
+  template:
+    metadata:
+      labels:
+        application: custom-metrics-consumer
+        version: latest
+    spec:
+      containers:
+      - name: custom-metrics-consumer
+        image: mikkeloscar/custom-metrics-consumer:latest
+        args:
+        - --fake-queue-length=2000
+        resources:
+          limits:
+            cpu: 10m
+            memory: 25Mi
+          requests:
+            cpu: 10m
+            memory: 25Mi

example/deploy/hpa.yaml

@@ -0,0 +1,60 @@
+apiVersion: autoscaling/v2beta2
+kind: HorizontalPodAutoscaler
+metadata:
+  name: custom-metrics-consumer
+  namespace: default
+  labels:
+    application: custom-metrics-consumer
+  annotations:
+    # metric-config.<metricType>.<metricName>.<collectorName>/<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"
+    # metric-config.object.requests-per-second.prometheus/query: |
+    #   scalar(sum(rate(skipper_serve_host_duration_seconds_count{host="custom-metrics_example_org"}[1m])))
+    # metric-config.object.requests-per-second.prometheus/per-replica: "true"
+    # metric-config.object.requests-per-second.skipper/interval: "1s"
+spec:
+  scaleTargetRef:
+    apiVersion: apps/v1
+    kind: Deployment
+    name: custom-metrics-consumer
+  minReplicas: 1
+  maxReplicas: 10
+  metrics:
+  # - type: Resource
+  #   resource:
+  #     name: cpu
+  #     current:
+  #       averageUtilization: 50
+
+  - type: Pods
+    pods:
+      metric:
+        name: queue-length
+      target:
+        averageValue: 1k
+        type: AverageValue
+
+  - type: Object
+    object:
+      describedObject:
+        apiVersion: extensions/v1beta1
+        kind: Ingress
+        name: custom-metrics-consumer
+      metric:
+        name: requests-per-second
+      target:
+        averageValue: "10"
+        type: AverageValue
+  - type: External
+    external:
+      metric:
+        name: sqs-queue-length
+        selector:
+          matchLabels:
+            queue-name: foobar
+            region: eu-central-1
+      target:
+        averageValue: "30"
+        type: AverageValue

example/deploy/ingress.yaml

@@ -0,0 +1,14 @@
+apiVersion: extensions/v1beta1
+kind: Ingress
+metadata:
+  name: custom-metrics-consumer
+  labels:
+    application: custom-metrics-consumer
+spec:
+  rules:
+  - host: custom-metrics.example.org
+    http:
+      paths:
+      - backend:
+          serviceName: custom-metrics-consumer
+          servicePort: 80

example/deploy/service.yaml

@@ -0,0 +1,14 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: custom-metrics-consumer
+  labels:
+    application: custom-metrics-consumer
+spec:
+  ports:
+  - port: 80
+    protocol: TCP
+    targetPort: 9090
+  selector:
+    application: custom-metrics-consumer
+  type: ClusterIP

example/main.go

@@ -0,0 +1,35 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"net/http"
+	"time"
+)
+
+func metricsHandler(w http.ResponseWriter, r *http.Request) {
+	w.WriteHeader(200)
+	_, err := w.Write([]byte(fmt.Sprintf(`{"queue": {"length": %d}}`, size)))
+	log.Fatalf("failed to write: %v", err)
+}
+
+var (
+	size int
+)
+
+func main() {
+	flag.IntVar(&size, "fake-queue-length", 10, "Fake queue length for fake metrics.")
+	flag.Parse()
+
+	mux := http.NewServeMux()
+	mux.HandleFunc("/metrics", metricsHandler)
+
+	server := &http.Server{
+		Addr:        ":9090",
+		Handler:     mux,
+		ReadTimeout: 5 * time.Second,
+	}
+
+	log.Fatal(server.ListenAndServe())
+}

go.mod

@@ -0,0 +1,33 @@
+module github.com/zalando-incubator/kube-metrics-adapter
+
+require (
+	github.com/NYTimes/gziphandler v1.0.1 // indirect
+	github.com/aws/aws-sdk-go v1.29.4
+	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 v1.4.0
+	github.com/tmc/grpc-websocket-proxy v0.0.0-20171017195756-830351dc03c6 // indirect
+	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/code-generator v0.17.4
+	k8s.io/component-base v0.0.0-20190918160511-547f6c5d7090
+	k8s.io/klog v1.0.0
+	k8s.io/metrics v0.0.0-20190226180357-f3f09b9076d1
+)
+
+go 1.13