feat(pod-delete): Adding pod-delete experiment in go (#1)

* feat(pod-delete): Adding pod-delete experiment in go

Signed-off-by: shubhamchaudhary <shubham.chaudhary@mayadata.io>

* update(pod-delete): travis changes

Signed-off-by: shubhamchaudhary <shubham.chaudhary@mayadata.io>

.gitignore

@@ -0,0 +1 @@
+build/_output

.travis.yml

@@ -0,0 +1,23 @@
+sudo: required
+dist: xenial
+
+services:
+  - docker
+language: go
+go:
+  - 1.13.1
+
+addons:
+  apt:
+    update: true
+
+script:
+  # Installing and configuring dependencies
+  - make deps
+  # Building go binaries
+  - make go-build
+  # Build
+  - make build
+
+after_success:
+  - make push

Makefile

@@ -0,0 +1,59 @@
+# Makefile for building Litmus and its tools
+# Reference Guide - https://www.gnu.org/software/make/manual/make.html
+
+#
+# Internal variables or constants.
+# NOTE - These will be executed when any make target is invoked.
+#
+IS_DOCKER_INSTALLED = $(shell which docker >> /dev/null 2>&1; echo $$?)
+
+.PHONY: all
+all: deps go-build build push
+
+.PHONY: help
+help:
+	@echo ""
+	@echo "Usage:-"
+	@echo "\tmake all   -- [default] builds the litmus containers"
+	@echo ""
+
+.PHONY: deps
+deps: _build_check_docker
+
+_build_check_docker:
+	@echo "------------------"
+	@echo "--> Check the Docker deps" 
+	@echo "------------------"
+	@if [ $(IS_DOCKER_INSTALLED) -eq 1 ]; \
+		then echo "" \
+		&& echo "ERROR:\tdocker is not installed. Please install it before build." \
+		&& echo "" \
+		&& exit 1; \
+		fi;
+
+PHONY: go-build
+go-build: experiment-go-binary
+
+experiment-go-binary:
+	@echo "------------------"
+	@echo "--> Build experiment go binary" 
+	@echo "------------------"
+	@sh build/generate_go_binary
+
+.PHONY: build
+build: litmus-go-build
+
+litmus-go-build:
+	@echo "------------------"
+	@echo "--> Build litmus-go image" 
+	@echo "------------------"
+	sudo docker build . -f build/litmus-go/Dockerfile -t litmuschaos/litmus-go:ci
+
+.PHONY: push
+push: litmus-go-push
+
+litmus-go-push:
+	@echo "------------------"
+	@echo "--> litmus-go image" 
+	@echo "------------------"
+	REPONAME="litmuschaos" IMGNAME="litmus-go" IMGTAG="ci" ./hack/push

README.md

@@ -1,7 +1,7 @@
-# litmus-python: 
+# litmus-go: 
 
 This repo consists of Litmus Chaos Experiments written in golang. The examples in this repo are good indicators 
-of how to construct the experiments in golang: complete with steady state checks, chaosresult generation, chaos injectionm, 
+of how to construct the experiments in golang: complete with steady state checks, chaosresult generation, chaos injection etc.., 
 post chaos checks, create events and reports for observability and configure sinks for these.  
 
 **NOTE**

build/generate_go_binary

@@ -0,0 +1,2 @@
+# Building go binaries for pod_delete experiment
+go build -o build/_output/pod-delete ./experiments/generic/pod-delete

build/litmus-go/Dockerfile

@@ -0,0 +1,9 @@
+FROM ubuntu:bionic
+
+LABEL maintainer="LitmusChaos"
+
+#Installing necessary ubuntu packages
+RUN apt-get update && apt-get install -y curl
+
+#Copying Necessary Files
+COPY ./build/_output ./experiments

build/push

@@ -0,0 +1,37 @@
+#!/bin/bash
+set -e
+
+if [ -z "${REPONAME}" ]
+then 
+  REPONAME="litmuschaos"
+fi
+
+if [ -z "${IMGNAME}" ] || [ -z "${IMGTAG}" ]; 
+then
+  echo "Image details are missing. Nothing to push."; 
+  exit 1
+fi
+
+IMAGEID=$( sudo docker images -q ${REPONAME}/${IMGNAME}:${IMGTAG} )
+
+if [ ! -z "${DNAME}" ] && [ ! -z "${DPASS}" ]; 
+then 
+  sudo docker login -u "${DNAME}" -p "${DPASS}";
+  # Push image to docker hub
+  echo "Pushing ${REPONAME}/${IMGNAME}:${IMGTAG} ..."; 
+  sudo docker push ${REPONAME}/${IMGNAME}:${IMGTAG} ;
+  if [ ! -z "${TRAVIS_TAG}" ] ; 
+  then
+    # Push with different tags if tagged as a release
+    # When github is tagged with a release, then Travis will 
+    # set the release tag in env TRAVIS_TAG
+    echo "Pushing ${REPONAME}/${IMGNAME}:${TRAVIS_TAG} ..."; 
+    sudo docker tag ${IMAGEID} ${REPONAME}/${IMGNAME}:${TRAVIS_TAG}
+    sudo docker push ${REPONAME}/${IMGNAME}:${TRAVIS_TAG}; 
+    echo "Pushing ${REPONAME}/${IMGNAME}:latest ..."; 
+    sudo docker tag ${IMAGEID} ${REPONAME}/${IMGNAME}:latest
+    sudo docker push ${REPONAME}/${IMGNAME}:latest; 
+  fi;
+else
+  echo "No docker credentials provided. Skip uploading ${REPONAME}/${IMGNAME}:${IMGTAG} to docker hub"; 
+fi;

chaoslib/litmus/pod_delete/pod-delete.go

@@ -0,0 +1,144 @@
+package pod_delete
+
+import (
+	"k8s.io/klog"
+	"time"
+
+    "github.com/litmuschaos/litmus-go/pkg/types"
+    "github.com/litmuschaos/litmus-go/pkg/status"
+    "github.com/litmuschaos/litmus-go/pkg/environment"
+	"k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+//PodDeleteChaos deletes the random single/multiple pods
+func PodDeleteChaos(experimentsDetails *types.ExperimentDetails, clients environment.ClientSets, Iterations int, resultDetails *types.ResultDetails) error {
+
+	//ChaosStartTimeStamp contains the start timestamp, when the chaos injection begin
+	ChaosStartTimeStamp := time.Now().Unix()
+
+	for x := 0; x < Iterations; x++ {
+
+		//Getting the list of all the target pod for deletion
+		targetPodList, err := PreparePodList(experimentsDetails, clients,resultDetails)
+		if err != nil {
+			return err
+		}
+		klog.V(0).Infof("Killing %v pods", targetPodList)
+
+		//Deleting the application pod
+		for _, pods := range targetPodList {
+			err := clients.KubeClient.CoreV1().Pods(experimentsDetails.AppNS).Delete(pods, &v1.DeleteOptions{})
+			if err != nil {
+				resultDetails.FailStep = "Deleting the application pod"
+				return err
+			}
+		}
+
+		//ChaosCurrentTimeStamp contains the current timestamp
+		ChaosCurrentTimeStamp := time.Now().Unix()
+
+		//ChaosDiffTimeStamp contains the difference of current timestamp and start timestamp
+		//It will helpful to track the total chaos duration
+		chaosDiffTimeStamp := ChaosCurrentTimeStamp - ChaosStartTimeStamp
+
+		if int(chaosDiffTimeStamp) >= experimentsDetails.ChaosDuration {
+			break
+		}
+
+		//Waiting for the chaos interval after chaos injection
+		if experimentsDetails.ChaosInterval != 0 {
+			klog.V(0).Infof("[Wait]: Wait for the chaos interval %vs", experimentsDetails.ChaosInterval)
+			waitForChaosInterval(experimentsDetails)
+		}
+		//Verify the status of pod after the chaos injection
+		klog.V(0).Infof("[Status]: Verification for the recreation of application pod")
+		err = status.CheckApplicationStatus(experimentsDetails.AppNS, experimentsDetails.AppLabel, clients)
+		if err != nil {
+			resultDetails.FailStep = "Verification for the recreation of application pod"
+			return err
+		}
+	}
+
+	return nil
+}
+
+//PreparePodDelete contains the steps for prepration before chaos
+func PreparePodDelete(experimentsDetails *types.ExperimentDetails, clients environment.ClientSets, resultDetails *types.ResultDetails) error {
+
+	//It will get the total iteration for the pod-delete
+	Iterations := GetIterations(experimentsDetails)
+	//Waiting for the ramp time before chaos injection
+	if experimentsDetails.RampTime != 0 {
+		klog.V(0).Infof("[Ramp]: Waiting for the %vs ramp time before injecting chaos", experimentsDetails.RampTime)
+		waitForRampTime(experimentsDetails)
+	}
+	//Deleting for the application pod
+	err := PodDeleteChaos(experimentsDetails, clients, Iterations, resultDetails)
+	if err != nil{
+		return err
+	}
+	//Waiting for the ramp time after chaos injection
+	if experimentsDetails.RampTime != 0 {
+		klog.V(0).Infof("[Ramp]: Waiting for the %vs ramp time after injecting chaos", experimentsDetails.RampTime)
+		waitForRampTime(experimentsDetails)
+	}
+	return nil
+}
+
+//GetIterations derive the iterations value from given parameters
+func GetIterations(experimentsDetails *types.ExperimentDetails) int {
+
+	Iterations := experimentsDetails.ChaosDuration / experimentsDetails.ChaosInterval
+	return Maximum(Iterations, 1)
+
+}
+
+//waitForRampTime waits for the given ramp time duration (in seconds)
+func waitForRampTime(experimentsDetails *types.ExperimentDetails) {
+	time.Sleep(time.Duration(experimentsDetails.RampTime) * time.Second)
+}
+
+//waitForChaosInterval waits for the given ramp time duration (in seconds)
+func waitForChaosInterval(experimentsDetails *types.ExperimentDetails) {
+	time.Sleep(time.Duration(experimentsDetails.ChaosInterval) * time.Second)
+}
+
+// Maximum calculates the maximum value among two integers
+func Maximum(a int, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+//Minimum calculates the minimum value among two integers
+func Minimum(a int, b int) int {
+	if a > b {
+		return b
+	}
+	return a
+}
+
+//PreparePodList derive the list of target pod for deletion
+//It is based on the KillCount value
+func PreparePodList(experimentsDetails *types.ExperimentDetails, clients environment.ClientSets, resultDetails *types.ResultDetails) ([]string, error) {
+
+	var targetPodList []string
+	//Getting the list of pods with the given labels and namespaces
+	pods, err := clients.KubeClient.CoreV1().Pods(experimentsDetails.AppNS).List(v1.ListOptions{LabelSelector: experimentsDetails.AppLabel})
+	if err != nil {
+		resultDetails.FailStep = "Getting the list of pods with the given labels and namespaces"
+		return targetPodList, err
+	}
+
+	//Adding the first pod only, if KillCount is not set or 0
+	//Otherwise derive the min(KIllCount,len(pod_list)) pod
+	if experimentsDetails.KillCount == 0 {
+		targetPodList = append(targetPodList, pods.Items[0].Name)
+	} else {
+		for i := 0; i < Minimum(experimentsDetails.KillCount, len(pods.Items)); i++ {
+			targetPodList = append(targetPodList, pods.Items[i].Name)
+		}
+	}
+	return targetPodList, err
+}

experiments/generic/pod-delete/pod-delete-k8s-job.yml

@@ -0,0 +1,63 @@
+---
+    apiVersion: batch/v1
+    kind: Job
+    metadata:
+      generateName: pod-delete-
+    spec:
+      template:
+        metadata:
+          labels:
+            experiment: pod-delete
+        spec:
+          # Placeholder that is updated by the executor for automated runs
+          # Provide appropriate SA (with desired permissions) if executed manually
+          serviceAccountName: litmus
+          restartPolicy: Never
+          containers:
+          - name: gotest
+            image: litmuschaos/litmus-go:ci
+            imagePullPolicy: Always
+            env:
+              - name: ANSIBLE_STDOUT_CALLBACK
+                value: 'default'
+
+              # provide application namespace
+              - name: APP_NAMESPACE
+                value: ''
+
+              # provide application labels
+              - name: APP_LABEL
+                value: ''
+
+               # provide application kind
+              - name: APP_KIND
+                value: ''
+
+              - name: TOTAL_CHAOS_DURATION
+                value: '30'
+
+              - name: CHAOS_INTERVAL
+                value: '10'
+
+              - name: CHAOS_NAMESPACE
+                value: ''
+
+                ## Period to wait before/after injection of chaos  
+              - name: RAMP_TIME
+                value: ''
+
+              ## env var that describes the library used to execute the chaos
+              ## Only supported litmus
+              - name: LIB
+                value: 'litmus'
+
+              - name: CHAOSENGINE
+                value: ''
+
+              - name: CHAOS_SERVICE_ACCOUNT
+                valueFrom:
+                  fieldRef:
+                    fieldPath: spec.serviceAccountName
+
+            command: ["/bin/bash"]
+            args: ["-c", "./experiments/pod-delete"]