added chaos cmd to peridically create & delete deployments in given t…

…ime interval

README.md

@@ -233,6 +233,16 @@ default           1300            1300            456             250
 kube-system       8               11              4               0               15          0           0           0               
 mock-kubelet      3500            4000            1200            400             9348        50          30          35     
 ```
+
+
+#### To create & delete periodically the deployments with provided time interval (i.e in seconds)
+
+The below cmd would create & delete 100 deployments with replicas as 50 for every 10 seconds in scale namespace.
+
+```
+./k8s-scaler chaos d --scale 100 -r 50 --time 10 -n scale
+```
+
 #### TODO:
 
 1. Support custom resources creation at scale. As CRD already exists in cluster. CR creation can be done using k8s-scaler by passing ```--kind``` value but custom resources spec formation needs to be taken care in k8s-scaler.

cmd/chaos.go

@@ -0,0 +1,90 @@
+/*
+Copyright © 2020 NAME HERE <EMAIL ADDRESS>
+
+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 cmd
+
+import (
+	kube_client "github.com/VineethReddy02/k8s-scaler/pkg/kube-client"
+	v1 "k8s.io/api/core/v1"
+	"log"
+	"strings"
+
+	"github.com/spf13/cobra"
+)
+
+// chaosCmd represents the chaos command
+var chaosCmd = &cobra.Command{
+	Use:   "chaos",
+	Short: "A brief description of your command",
+	Long: `A longer description that spans multiple lines and likely contains examples
+and usage of using your command. For example:
+
+Cobra is a CLI library for Go that empowers applications.
+This application is a tool to generate the needed files
+to quickly create a Cobra application.`,
+	Run: func(cmd *cobra.Command, args []string) {
+		resourceType := args[0]
+		count, _ := cmd.Flags().GetInt32("scale")
+		replicas, _ := cmd.Flags().GetInt32("replicas")
+		containers, _ := cmd.Flags().GetInt32("containers")
+		config, _ := rootCmd.PersistentFlags().GetString("kubeconfig")
+		namespace, _ := cmd.Flags().GetString("namespace")
+		namespaces, _ := cmd.Flags().GetString("exclude-namespaces")
+		excludeNamespaces := strings.Split(namespaces, ",")
+		nodeselector, _ := cmd.Flags().GetString("node-selector")
+		toleration, _ := cmd.Flags().GetString("toleration")
+		timeInterval, _ := cmd.Flags().GetInt32("time")
+		if nodeselector != "" {
+			ns := strings.Split(nodeselector, "=")
+			kube_client.Config.NodeSelector = map[string]string{ns[0]:ns[1]}
+		} else {
+			kube_client.Config.NodeSelector = nil
+		}
+		if toleration != "" {
+			ts := strings.Split(toleration, "=")
+			toleration := &v1.Toleration{
+				Key:               ts[0],
+				Operator:          "Equal",
+				Value:             ts[1],
+				Effect:            "NoSchedule",
+			}
+			kube_client.Config.Tolerations = append(kube_client.Config.Tolerations, *toleration)
+		}else {
+			kube_client.Config.Tolerations = nil
+		}
+
+		kubeClient := kube_client.NewKubeClient()
+		clientInfo := kubeClient.GetKubeClient(config)
+		kubeClient.Client = clientInfo
+		if resourceType == "deployments" ||  resourceType == "d" {
+			kubeClient.CreateChaosWithDeployments(count, replicas, containers, namespace, excludeNamespaces, timeInterval)
+		} else {
+			log.Fatal("k8s-scaler only creating chaos with deployments")
+		}
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(chaosCmd)
+
+	chaosCmd.Flags().Int32P("scale", "s", 1, "number of instances.")
+	chaosCmd.Flags().Int32P("replicas", "r", 1, "number of replicas per instance.")
+	chaosCmd.Flags().Int32P("containers", "c", 1, "number of containers per pod.")
+	chaosCmd.Flags().StringP("namespace", "n", "", "specify the namespace")
+	chaosCmd.Flags().String("node-selector", "", "specify the node selector as map key=value")
+	chaosCmd.Flags().StringP("toleration", "t", "", "specify the toleration for a specific node as map key=value")
+	chaosCmd.Flags().StringP("exclude-namespaces", "e", "", "specify namespaces that needs to be excluded during creation.")
+	chaosCmd.Flags().Int32P("time", "", 300, "time interval between creation & deletion, default to 5 minutes.")
+}

pkg/kube-client/chaos.go

@@ -0,0 +1,13 @@
+package kube_client
+
+import "time"
+
+func (ctx *KubeClient) CreateChaosWithDeployments(count, replicas, containers int32, namespace string, excludeNamespaces []string, timeInterval int32) {
+	ticker := time.NewTicker(time.Duration(timeInterval) * time.Second)
+	for {
+		ctx.CreateDeployments(count, replicas, containers, namespace, excludeNamespaces)
+		<-ticker.C
+		ctx.DeleteDeployments(count, namespace, excludeNamespaces)
+		<-ticker.C
+	}
+}