Executor: Dump function service cache for pool manager functions (#2789)

* dump function service cache for executor
* fix lint issue
* code refactor and lint fixes

---------

Signed-off-by: Shubham Bansal <shubhambansaliimtgn@gmail.com>
Signed-off-by: Sanket Sudake <sanketsudake@gmail.com>
Co-authored-by: Sanket Sudake <sanketsudake@gmail.com>

pkg/executor/util/util.go

@@ -35,6 +35,10 @@ import (
 	"github.com/fission/fission/pkg/utils"
 )
 
+const (
+	dumpFileName string = "fission-dump"
+)
+
 // ApplyImagePullSecret applies image pull secret to the give pod spec.
 // It's intentional not to check the existence of secret here.
 // First, Kubernetes will set Pod status to "ImagePullBackOff" once
@@ -152,3 +156,11 @@ func GetObjectReaperInterval(logger *zap.Logger, executorType fv1.ExecutorType,
 func getExecutorEnvVarName(executor fv1.ExecutorType) string {
 	return strings.ToUpper(string(executor)) + "_OBJECT_REAPER_INTERVAL"
 }
+
+// CreateDumpFile => create dump file inside temp directory
+func CreateDumpFile(logger *zap.Logger) (*os.File, error) {
+	dumpPath := os.TempDir()
+	logger.Info("creating dump file", zap.String("dump_path", dumpPath))
+
+	return os.Create(fmt.Sprintf("%s/%s-%d.txt", dumpPath, dumpFileName, time.Now().Unix()))
+}