[CHAOSPLT-1330][FIX] PodReplacement: Ignore container requirement

api/v1beta1/pod_replacement.go

@@ -5,7 +5,11 @@
 
 package v1beta1
 
-import "strconv"
+import (
+	"strconv"
+
+	chaostypes "github.com/DataDog/chaos-controller/types"
+)
 
 // PodReplacementSpec represents a pod replacement disruption
 type PodReplacementSpec struct {
@@ -27,7 +31,7 @@ func (s *PodReplacementSpec) Validate() error {
 // GenerateArgs generates injection or cleanup pod arguments for the given spec
 func (s *PodReplacementSpec) GenerateArgs() []string {
 	args := []string{
-		"pod-replacement",
+		chaostypes.DisruptionKindPodReplacement,
 		"inject",
 	}
 

cli/injector/main.go

@@ -222,6 +222,16 @@ func initConfig() {
 	// assign to the pointer to level the new value to persist it after this method
 	disruptionArgs.Level = chaostypes.DisruptionLevel(disruptionLevelRaw)
 
+	// check if we're running pod-replacement command which doesn't need containers
+	isPodReplacement := false
+
+	for _, arg := range os.Args {
+		if arg == chaostypes.DisruptionKindPodReplacement {
+			isPodReplacement = true
+			break
+		}
+	}
+
 	switch disruptionArgs.Level {
 	case chaostypes.DisruptionLevelPod:
 		// check for container ID flag
@@ -231,33 +241,39 @@ func initConfig() {
 			return
 		}
 
-		for containerName, containerID := range disruptionArgs.TargetContainers {
-			// retrieve container info
-			ctn, err := container.New(containerID, containerName)
-			if err != nil {
-				log.Fatalw("can't create container object", tags.ErrorKey, err)
+		if !isPodReplacement {
+			// Pod replacement operates at the pod level and doesn't need container information
+			for containerName, containerID := range disruptionArgs.TargetContainers {
+				// retrieve container info
+				ctn, err := container.New(containerID, containerName)
+				if err != nil {
+					log.Fatalw("can't create container object", tags.ErrorKey, err)
 
-				return
-			}
+					return
+				}
 
-			log.Infow("injector targeting container", tags.ContainerIDKey, containerID, tags.ContainerNameKey, containerName)
+				log.Infow("injector targeting container", tags.ContainerIDKey, containerID, tags.ContainerNameKey, containerName)
 
-			pid := ctn.PID()
+				pid := ctn.PID()
 
-			// keep pid for later if this is a chaos handler container
-			if disruptionArgs.OnInit && ctn.Name() == chaosInitContName {
-				handlerPID = pid
-			}
+				// keep pid for later if this is a chaos handler container
+				if disruptionArgs.OnInit && ctn.Name() == chaosInitContName {
+					handlerPID = pid
+				}
 
-			ctns = append(ctns, ctn)
-			pids = append(pids, pid)
-		}
+				ctns = append(ctns, ctn)
+				pids = append(pids, pid)
+			}
+		} else {
+			// check for pod IP flag
+			if disruptionArgs.TargetPodIP == "" {
+				log.Fatal("--target-pod-ip flag must be passed when --level=pod")
 
-		// check for pod IP flag
-		if disruptionArgs.TargetPodIP == "" {
-			log.Fatal("--target-pod-ip flag must be passed when --level=pod")
+				return
+			}
 
-			return
+			pids = []uint32{1}
+			ctns = []container.Container{nil}
 		}
 	case chaostypes.DisruptionLevelNode:
 		pids = []uint32{1}

cli/injector/pod_replacement.go

@@ -8,14 +8,16 @@ package main
 import (
 	"strconv"
 
+	"github.com/spf13/cobra"
+
 	"github.com/DataDog/chaos-controller/api/v1beta1"
 	"github.com/DataDog/chaos-controller/injector"
 	"github.com/DataDog/chaos-controller/o11y/tags"
-	"github.com/spf13/cobra"
+	chaostypes "github.com/DataDog/chaos-controller/types"
 )
 
 var podReplacementCmd = &cobra.Command{
-	Use:   "pod-replacement",
+	Use:   chaostypes.DisruptionKindPodReplacement,
 	Short: "Pod replacement subcommands",
 	Run:   injectAndWait,
 	PreRun: func(cmd *cobra.Command, args []string) {

examples/demo.yaml

@@ -217,6 +217,30 @@ spec:
             requests:
               memory: 16Mi
               cpu: 10m
+        ## Create a second container to ensure the pod replace is working as expected
+        - name: storage-monitor-2
+          image: alpine:latest
+          command: ["/bin/sh"]
+          args:
+            - -c
+            - |
+              echo "Storage monitoring container started"
+              # Create a test file to demonstrate persistence
+              echo "demo-storage-$(date)" > /mnt/shared/storage-info.txt
+              # Keep container running and periodically update the file
+              while true; do
+                echo "$(date): Storage is available" >> /mnt/shared/heartbeat.log
+                sleep 30
+              done
+          volumeMounts:
+            - mountPath: /mnt/shared
+              name: shared-storage
+          resources:
+            limits:
+              memory: 16Mi
+              cpu: 10m
+            requests:
+              memory: 16Mi
   volumeClaimTemplates:
     - metadata:
         name: shared-storage