Add openapi spec (#1512)

* Add openapi spec

Signed-off-by: Suresh Kumar Ponnusamy <suresh.ponnusamy@freshworks.com>

* Update changelog

Signed-off-by: Suresh Kumar Ponnusamy <suresh.ponnusamy@freshworks.com>

* Update CHANGELOG.md

Signed-off-by: Suresh Kumar Ponnusamy <suresh.ponnusamy@freshworks.com>

* Move generated openapi file

Signed-off-by: Suresh Kumar Ponnusamy <suresh.ponnusamy@freshworks.com>

* Update generated code

Signed-off-by: Suresh Kumar Ponnusamy <suresh.ponnusamy@freshworks.com>

* Fix import grouping

Signed-off-by: Suresh Kumar Ponnusamy <suresh.ponnusamy@freshworks.com>

* Update autogenerated tag

Signed-off-by: Suresh Kumar Ponnusamy <suresh.ponnusamy@freshworks.com>

* Update CHANGELOG.md

Co-authored-by: Zbynek Roubalik <726523+zroubalik@users.noreply.github.com>
Signed-off-by: Suresh Kumar Ponnusamy <suresh.ponnusamy@freshworks.com>

* Disable static linter for a stackdriver scaler

Signed-off-by: Suresh Kumar Ponnusamy <suresh.ponnusamy@freshworks.com>

* Sync go module in workflow run

Signed-off-by: Suresh Kumar Ponnusamy <suresh.ponnusamy@freshworks.com>

* Fix 'go list' invocation.

It appears go1.14 introduced different behavior when running 'go list' with
vendor directory (which our Makefile seems to create temporarily and not
cleanup). This change makes 'go list' work with even when vendor directory
is present

Signed-off-by: Suresh Kumar Ponnusamy <suresh.ponnusamy@freshworks.com>

Co-authored-by: Zbynek Roubalik <726523+zroubalik@users.noreply.github.com>

.github/workflows/pr-validation.yml

@@ -23,6 +23,9 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-go-
 
+      - name: Go modules sync
+        run: go mod tidy
+
       - name: Verify Generated clientset is up to date
         run: make clientset-verify
 

.golangci.yml

@@ -60,7 +60,10 @@ issues:
     - path: _finalizer.go
       linters:
         - interfacer
-
+    # Excluding the stackdriver_client scaler until it is fixed: https://github.com/kedacore/keda/pull/1512#issuecomment-763454243
+    - path: pkg/scalers/stackdriver_client.go
+      linters:
+        - staticcheck
     # https://github.com/go-critic/go-critic/issues/926
     - linters:
         - gocritic

CHANGELOG.md

@@ -39,6 +39,7 @@
 - Improve performance when fetching current scaling information on Deployments ([#1458](https://github.com/kedacore/keda/pull/1458))
 - Improve error reporting in prometheus scaler ([#1497](https://github.com/kedacore/keda/pull/1497))
 - Check that metricNames are unique in ScaledObject ([#1390](https://github.com/kedacore/keda/pull/1390))
+- Serve OpenAPI spec from KEDA Metrics Apiserver ([#1512](https://github.com/kedacore/keda/pull/1512))
 
 ### Breaking Changes
 

Makefile

@@ -173,9 +173,20 @@ manifests: controller-gen
 
 # Generate code (API)
 .PHONY: generate
-generate: controller-gen
+generate: controller-gen adapter/generated/openapi/zz_generated.openapi.go
 	$(CONTROLLER_GEN) object:headerFile="hack/boilerplate.go.txt" paths="./..."
 
+adapter/generated/openapi/zz_generated.openapi.go: go.mod go.sum
+	@OPENAPI_PATH=`go list -mod=readonly -m -f '{{.Dir}}' k8s.io/kube-openapi`; \
+	go run $${OPENAPI_PATH}/cmd/openapi-gen/openapi-gen.go --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 \
+	    --build-tag autogenerated \
+	    -h ./hack/boilerplate.go.txt \
+	    -p ./adapter/generated/openapi \
+	    -O zz_generated.openapi \
+	    -o ./ \
+	    -r /dev/null
+
 # find or download controller-gen
 # download controller-gen if necessary
 .PHONY: controller-gen

adapter/main.go

@@ -10,15 +10,18 @@ import (
 
 	appsv1 "k8s.io/api/apps/v1"
 	"k8s.io/apimachinery/pkg/util/wait"
+	openapinamer "k8s.io/apiserver/pkg/endpoints/openapi"
+	genericapiserver "k8s.io/apiserver/pkg/server"
 	"k8s.io/client-go/kubernetes/scheme"
 	"k8s.io/klog"
 	"k8s.io/klog/klogr"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 	"sigs.k8s.io/controller-runtime/pkg/client/config"
 
-	basecmd "github.com/kubernetes-incubator/custom-metrics-apiserver/pkg/cmd"
-	"github.com/kubernetes-incubator/custom-metrics-apiserver/pkg/provider"
+	basecmd "github.com/kubernetes-sigs/custom-metrics-apiserver/pkg/cmd"
+	"github.com/kubernetes-sigs/custom-metrics-apiserver/pkg/provider"
 
+	generatedopenapi "github.com/kedacore/keda/v2/adapter/generated/openapi"
 	kedav1alpha1 "github.com/kedacore/keda/v2/api/v1alpha1"
 	prommetrics "github.com/kedacore/keda/v2/pkg/metrics"
 	kedaprovider "github.com/kedacore/keda/v2/pkg/provider"
@@ -111,6 +114,11 @@ func main() {
 	printVersion()
 
 	cmd := &Adapter{}
+
+	cmd.OpenAPIConfig = genericapiserver.DefaultOpenAPIConfig(generatedopenapi.GetOpenAPIDefinitions, openapinamer.NewDefinitionNamer(scheme.Scheme))
+	cmd.OpenAPIConfig.Info.Title = "keda-adapter"
+	cmd.OpenAPIConfig.Info.Version = "1.0.0"
+
 	cmd.Flags().StringVar(&cmd.Message, "msg", "starting adapter...", "startup message")
 	cmd.Flags().AddGoFlagSet(flag.CommandLine) // make sure we get the klog flags
 	cmd.Flags().IntVar(&prometheusMetricsPort, "metrics-port", 9022, "Set the port to expose prometheus metrics")

go.mod

@@ -15,7 +15,9 @@ require (
 	github.com/Huawei/gophercloud v1.0.21
 	github.com/Shopify/sarama v1.27.2
 	github.com/aws/aws-sdk-go v1.36.19
-	github.com/go-logr/logr v0.1.0
+	github.com/go-logr/logr v0.3.0
+	github.com/go-logr/zapr v0.3.0 // indirect
+	github.com/go-openapi/spec v0.20.0
 	github.com/go-redis/redis v6.15.9+incompatible
 	github.com/go-sql-driver/mysql v1.5.0
 	github.com/golang/mock v1.4.4
@@ -24,7 +26,7 @@ require (
 	github.com/hashicorp/vault/api v1.0.4
 	github.com/imdario/mergo v0.3.11
 	github.com/influxdata/influxdb-client-go/v2 v2.2.1
-	github.com/kubernetes-incubator/custom-metrics-apiserver v0.0.0-20200618121405-54026617ec44
+	github.com/kubernetes-sigs/custom-metrics-apiserver v0.0.0-20201216091021-1b9fa998bbaa
 	github.com/lib/pq v1.9.0
 	github.com/mitchellh/hashstructure v1.1.0
 	github.com/onsi/ginkgo v1.14.2
@@ -39,31 +41,23 @@ require (
 	go.mongodb.org/mongo-driver v1.1.2
 	golang.org/x/crypto v0.0.0-20201016220609-9e8e0b390897 // indirect
 	google.golang.org/api v0.36.0
-	google.golang.org/genproto v0.0.0-20200904004341-0bd0a958aa1d
+	google.golang.org/genproto v0.0.0-20201203001206-6486ece9c497
 	google.golang.org/grpc v1.34.0
-	k8s.io/api v0.18.8
-	k8s.io/apimachinery v0.18.8
-	k8s.io/client-go v12.0.0+incompatible
-	k8s.io/code-generator v0.18.8
+	k8s.io/api v0.20.2
+	k8s.io/apimachinery v0.20.2
+	k8s.io/apiserver v0.20.2
+	k8s.io/client-go v11.0.1-0.20190805182717-6502b5e7b1b5+incompatible
+	k8s.io/code-generator v0.20.0
 	k8s.io/klog v1.0.0
-	k8s.io/metrics v0.18.8
+	k8s.io/kube-openapi v0.0.0-20201113171705-d219536bb9fd
+	k8s.io/metrics v0.20.0
 	knative.dev/pkg v0.0.0-20201019114258-95e9532f0457
 	sigs.k8s.io/controller-runtime v0.6.4
 )
 
-replace (
-	k8s.io/apiserver => k8s.io/apiserver v0.18.8 // Required by kubernetes-incubator/custom-metrics-apiserver
-	k8s.io/client-go => k8s.io/client-go v0.18.8
-)
-
-// Required to resolve go/grpc issues
-// (grpc version needed by k8s.io/apiserver vs kubernetes-incubator/custom-metrics-apiserver)
-replace (
-	cloud.google.com/go => cloud.google.com/go v0.48.0
-	google.golang.org/api => google.golang.org/api v0.15.1
-	google.golang.org/genproto => google.golang.org/genproto v0.0.0-20191002211648-c459b9ce5143
-	google.golang.org/grpc => google.golang.org/grpc v1.26.0
-)
+replace k8s.io/client-go => k8s.io/client-go v0.20.2
 
-// Required for k8s.io/apiserver, using k8s.io/kube-openapi branch release-1.18
-replace k8s.io/kube-openapi => k8s.io/kube-openapi v0.0.0-20200410145947-61e04a5be9a6
+// adapter uses k8s.io/apiserver/pkg/server, which indirectly uses go.etcd.io/etcd/proxy/grpcproxy.
+// etcd is not compatible with newer grpc version, see here https://github.com/etcd-io/etcd/issues/12124
+// so until that is fixed, we will pin the grpc version to v1.29.1
+replace google.golang.org/grpc => google.golang.org/grpc v1.29.1