Adding boilerplate files

Signed-off-by: Per Ploug <per.ploug@zalando.de>

pkg/server/start.go

@@ -0,0 +1,213 @@
+/*
+Copyright 2017 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.
+*/
+
+package server
+
+import (
+	"context"
+	"fmt"
+	"github.com/aws/aws-sdk-go/aws"
+	"time"
+
+	"github.com/aws/aws-sdk-go/aws/session"
+	"github.com/kubernetes-incubator/custom-metrics-apiserver/pkg/cmd/server"
+	"github.com/mikkeloscar/kube-metrics-adapter/pkg/collector"
+	"github.com/mikkeloscar/kube-metrics-adapter/pkg/provider"
+	"github.com/spf13/cobra"
+	"k8s.io/client-go/informers"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/rest"
+	"k8s.io/client-go/tools/clientcmd"
+)
+
+const (
+	defaultClientGOTimeout = 30 * time.Second
+)
+
+// NewCommandStartAdapterServer provides a CLI handler for 'start adapter server' command
+func NewCommandStartAdapterServer(stopCh <-chan struct{}) *cobra.Command {
+	baseOpts := server.NewCustomMetricsAdapterServerOptions()
+	o := AdapterServerOptions{
+		CustomMetricsAdapterServerOptions: baseOpts,
+		EnableCustomMetricsAPI:            true,
+		EnableExternalMetricsAPI:          true,
+	}
+
+	cmd := &cobra.Command{
+		Short: "Launch the custom metrics API adapter server",
+		Long:  "Launch the custom metrics API adapter server",
+		RunE: func(c *cobra.Command, args []string) error {
+			if err := o.Complete(); err != nil {
+				return err
+			}
+			if err := o.Validate(args); err != nil {
+				return err
+			}
+			if err := o.RunCustomMetricsAdapterServer(stopCh); err != nil {
+				return err
+			}
+			return nil
+		},
+	}
+
+	flags := cmd.Flags()
+	o.SecureServing.AddFlags(flags)
+	o.Authentication.AddFlags(flags)
+	o.Authorization.AddFlags(flags)
+	o.Features.AddFlags(flags)
+
+	flags.StringVar(&o.RemoteKubeConfigFile, "lister-kubeconfig", o.RemoteKubeConfigFile, ""+
+		"kubeconfig file pointing at the 'core' kubernetes server with enough rights to list "+
+		"any described objects")
+	flags.BoolVar(&o.EnableCustomMetricsAPI, "enable-custom-metrics-api", o.EnableCustomMetricsAPI, ""+
+		"whether to enable Custom Metrics API")
+	flags.BoolVar(&o.EnableExternalMetricsAPI, "enable-external-metrics-api", o.EnableExternalMetricsAPI, ""+
+		"whether to enable External Metrics API")
+	flags.StringVar(&o.PrometheusServer, "prometheus-server", o.PrometheusServer, ""+
+		"url of prometheus server to query")
+	flags.BoolVar(&o.SkipperIngressMetrics, "skipper-ingress-metrics", o.SkipperIngressMetrics, ""+
+		"whether to enable skipper ingress metrics")
+	flags.BoolVar(&o.AWSExternalMetrics, "aws-external-metrics", o.AWSExternalMetrics, ""+
+		"whether to enable AWS external metrics")
+	flags.StringSliceVar(&o.AWSRegions, "aws-region", o.AWSRegions, "the AWS regions which should be monitored. eg: eu-central, eu-west-1")
+
+	return cmd
+}
+
+func (o AdapterServerOptions) RunCustomMetricsAdapterServer(stopCh <-chan struct{}) error {
+	config, err := o.Config()
+	if err != nil {
+		return err
+	}
+
+	var clientConfig *rest.Config
+	if len(o.RemoteKubeConfigFile) > 0 {
+		loadingRules := &clientcmd.ClientConfigLoadingRules{ExplicitPath: o.RemoteKubeConfigFile}
+		loader := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(loadingRules, &clientcmd.ConfigOverrides{})
+
+		clientConfig, err = loader.ClientConfig()
+	} else {
+		clientConfig, err = rest.InClusterConfig()
+	}
+	if err != nil {
+		return fmt.Errorf("unable to construct lister client config to initialize provider: %v", err)
+	}
+
+	clientConfig.Timeout = defaultClientGOTimeout
+
+	client, err := kubernetes.NewForConfig(clientConfig)
+	if err != nil {
+		return fmt.Errorf("failed to initialize new client: %v", err)
+	}
+
+	collectorFactory := collector.NewCollectorFactory()
+
+	if o.PrometheusServer != "" {
+		promPlugin, err := collector.NewPrometheusCollectorPlugin(client, o.PrometheusServer)
+		if err != nil {
+			return fmt.Errorf("failed to initialize prometheus collector plugin: %v", err)
+		}
+
+		err = collectorFactory.RegisterObjectCollector("", "prometheus", promPlugin)
+		if err != nil {
+			return fmt.Errorf("failed to register prometheus collector plugin: %v", err)
+		}
+
+		// skipper collector can only be enabled if prometheus is.
+		if o.SkipperIngressMetrics {
+			skipperPlugin, err := collector.NewSkipperCollectorPlugin(client, promPlugin)
+			if err != nil {
+				return fmt.Errorf("failed to initialize skipper collector plugin: %v", err)
+			}
+
+			err = collectorFactory.RegisterObjectCollector("Ingress", "", skipperPlugin)
+			if err != nil {
+				return fmt.Errorf("failed to register skipper collector plugin: %v", err)
+			}
+		}
+	}
+
+	// register generic pod collector
+	err = collectorFactory.RegisterPodsCollector("", collector.NewPodCollectorPlugin(client))
+	if err != nil {
+		return fmt.Errorf("failed to register skipper collector plugin: %v", err)
+	}
+
+	awsSessions := make(map[string]*session.Session, len(o.AWSRegions))
+	for _, region := range o.AWSRegions {
+		awsSessions[region], err = session.NewSession(&aws.Config{Region: aws.String(region)})
+		if err != nil {
+			return fmt.Errorf("unabled to create aws session for region: %s", region)
+		}
+	}
+
+	if o.AWSExternalMetrics {
+		collectorFactory.RegisterExternalCollector([]string{collector.AWSSQSQueueLengthMetric}, collector.NewAWSCollectorPlugin(awsSessions))
+	}
+
+	hpaProvider := provider.NewHPAProvider(client, 30*time.Second, 1*time.Minute, collectorFactory)
+
+	// convert stop channel to a context
+	ctx, cancel := context.WithCancel(context.Background())
+	go func() {
+		<-stopCh
+		cancel()
+	}()
+
+	go hpaProvider.Run(ctx)
+
+	customMetricsProvider := hpaProvider
+	externalMetricsProvider := hpaProvider
+
+	// var externalMetricsProvider := nil
+	if !o.EnableCustomMetricsAPI {
+		customMetricsProvider = nil
+	}
+	if !o.EnableExternalMetricsAPI {
+		externalMetricsProvider = nil
+	}
+
+	informer := informers.NewSharedInformerFactory(client, 0)
+
+	// In this example, the same provider implements both Custom Metrics API and External Metrics API
+	server, err := config.Complete(informer).New("kube-metrics-adapter", customMetricsProvider, externalMetricsProvider)
+	if err != nil {
+		return err
+	}
+	return server.GenericAPIServer.PrepareRun().Run(ctx.Done())
+}
+
+type AdapterServerOptions struct {
+	*server.CustomMetricsAdapterServerOptions
+
+	// RemoteKubeConfigFile is the config used to list pods from the master API server
+	RemoteKubeConfigFile string
+	// EnableCustomMetricsAPI switches on sample apiserver for Custom Metrics API
+	EnableCustomMetricsAPI bool
+	// EnableExternalMetricsAPI switches on sample apiserver for External Metrics API
+	EnableExternalMetricsAPI bool
+	// PrometheusServer enables prometheus queries to the specified
+	// server.
+	PrometheusServer string
+	// SkipperIngressMetrics switches on support for skipper ingress based
+	// metric collection.
+	SkipperIngressMetrics bool
+	// AWSExternalMetrics switches on support for getting external metrics
+	// from AWS.
+	AWSExternalMetrics bool
+	// AWSRegions the AWS regions which are supported for monitoring.
+	AWSRegions []string
+}