[bugfix]: clean OCI leftovers before the wasp-agent pod is removed

manifests/openshift/ds.yaml

@@ -30,6 +30,14 @@ spec:
             quay.io/openshift-virtualization/wasp-agent:v4.17
           imagePullPolicy: Always
           name: wasp-agent
+          lifecycle:
+            preStop:
+              exec:
+                command:
+                  - rm
+                  - -f
+                  - /host/opt/oci-hook-swap.sh
+                  - /host/run/containers/oci/hooks.d/swap-for-burstable.json
           resources:
             requests:
               cpu: 100m

pkg/consts/consts.go

@@ -0,0 +1,10 @@
+package consts
+
+const (
+	HookTemplateFile     = "/app/OCI-hook/hookscript.template"
+	HookScriptPath       = "/host/opt/oci-hook-swap.sh"
+	HookConfigSource     = "/app/OCI-hook/swap-for-burstable.json"
+	HookConfigPath       = "/host/run/containers/oci/hooks.d/swap-for-burstable.json"
+	CrioConfigPath       = "/host/etc/crio/crio.conf"
+	CrioConfigDropInPath = "/host/etc/crio/crio.conf.d"
+)

pkg/wasp/application.go

@@ -22,14 +22,14 @@ import (
 	"context"
 	"flag"
 	"fmt"
+	"io"
+	"os"
 	"github.com/openshift-virtualization/wasp-agent/pkg/client"
 	"github.com/openshift-virtualization/wasp-agent/pkg/informers"
 	"github.com/openshift-virtualization/wasp-agent/pkg/log"
 	limited_swap_manager "github.com/openshift-virtualization/wasp-agent/pkg/wasp/limited-swap-manager"
-	"io"
 	"k8s.io/client-go/tools/cache"
 	"k8s.io/klog/v2"
-	"os"
 )
 
 type WaspApp struct {

pkg/wasp/oci.go

@@ -2,19 +2,12 @@ package wasp
 
 import (
 	"fmt"
+	"os"
+
+	"github.com/openshift-virtualization/wasp-agent/pkg/consts"
 	"github.com/openshift-virtualization/wasp-agent/pkg/wasp/config"
 	oci_hook_render "github.com/openshift-virtualization/wasp-agent/pkg/wasp/oci-hook-render"
 	"k8s.io/klog/v2"
-	"os"
-)
-
-const (
-	hookTemplateFile = "/app/OCI-hook/hookscript.template"
-	hookScriptPath   = "/host/opt/oci-hook-swap.sh"
-	// CrioConfigPath is the default location for the conf file.
-	CrioConfigPath = "/host/etc/crio/crio.conf"
-	// CrioConfigDropInPath is the default location for the drop-in config files.
-	CrioConfigDropInPath = "/host/etc/crio/crio.conf.d"
 )
 
 type crioConfiguration interface {
@@ -31,28 +24,29 @@ func setOCIHook() error {
 		return err
 	}
 
-	err = moveFile("/app/OCI-hook/swap-for-burstable.json", "/host/run/containers/oci/hooks.d/swap-for-burstable.json")
+	err = moveFile(consts.HookConfigSource, consts.HookConfigPath)
 	if err != nil {
 		return err
 	}
 
 	return nil
 }
 
+
 func setupHookScript() error {
-	crioConfig := crioConfiguration(config.New(CrioConfigPath, CrioConfigDropInPath))
+	crioConfig := crioConfiguration(config.New(consts.CrioConfigPath, consts.CrioConfigDropInPath))
 	runtime, err := crioConfig.GetRuntime()
 	if err != nil {
 		return err
 	}
 	klog.Infof("detected runtime " + runtime)
 
-	renderer := hookRenderer(oci_hook_render.New(hookTemplateFile, hookScriptPath, runtime))
+	renderer := hookRenderer(oci_hook_render.New(consts.HookTemplateFile, consts.HookScriptPath, runtime))
 	if err := renderer.Render(); err != nil {
 		return err
 	}
 
-	err = os.Chmod(hookScriptPath, 0755)
+	err = os.Chmod(consts.HookScriptPath, 0755)
 	if err != nil {
 		return fmt.Errorf("Couldn't set file permissions: %v", err)
 	}

pkg/wasp/resources/operator/operator.go

@@ -2,6 +2,8 @@ package operator
 
 import (
 	"fmt"
+
+	"github.com/openshift-virtualization/wasp-agent/pkg/consts"
 	"github.com/openshift-virtualization/wasp-agent/pkg/monitoring/rules"
 	utils2 "github.com/openshift-virtualization/wasp-agent/pkg/util"
 
@@ -117,6 +119,17 @@ func createWaspDaemonSet(namespace, verbosity, waspImage, pullPolicy string) *ap
 		SecurityContext: &corev1.SecurityContext{
 			Privileged: boolPtr(true),
 		},
+		Lifecycle: &corev1.Lifecycle{
+			PreStop: &corev1.LifecycleHandler{
+				Exec: &corev1.ExecAction{
+					Command: []string{
+						"rm", "-f",
+						consts.HookScriptPath,
+						consts.HookConfigPath,
+					},
+				},
+			},
+		},
 		VolumeMounts: []corev1.VolumeMount{
 			{
 				Name:      "host",