From e438df87fa53b13d88394b7c86b6268bc72e20d2 Mon Sep 17 00:00:00 2001
From: Gaurav Gahlot <gauravgahlot0107@gmail.com>
Date: Thu, 3 Dec 2020 22:29:35 +0530
Subject: [PATCH] Fixed golangci-lint issues: /fission/pkg/executor (#1842)

---
 go.mod                                        |  3 +-
 pkg/executor/api.go                           | 32 ++++++----
 pkg/executor/client/client.go                 | 46 ++++++++------
 pkg/executor/cms/cmscontroller.go             |  1 +
 pkg/executor/executor.go                      |  3 +
 pkg/executor/executor_test.go                 | 34 +++++++---
 .../executortype/newdeploy/newdeploy.go       |  1 +
 .../executortype/newdeploy/newdeploymgr.go    | 20 ++++--
 pkg/executor/executortype/poolmgr/gp.go       | 56 ++++++++++-------
 pkg/executor/executortype/poolmgr/gpm.go      | 28 +++++----
 pkg/executor/fscache/functionServiceCache.go  | 63 +++++++++++++++++--
 pkg/executor/fscache/metrics.go               |  1 +
 pkg/executor/reaper/reaper.go                 | 21 ++++---
 pkg/executor/util/merge.go                    |  1 +
 pkg/executor/util/util.go                     |  1 +
 15 files changed, 220 insertions(+), 91 deletions(-)

diff --git a/go.mod b/go.mod
index 741d2313..1f23edb5 100644
--- a/go.mod
+++ b/go.mod
@@ -53,7 +53,6 @@ require (
 	github.com/opencontainers/image-spec v1.0.1 // indirect
 	github.com/opencontainers/runc v0.1.1 // indirect
 	github.com/ory/dockertest v3.3.5+incompatible
-	github.com/pierrec/lz4 v2.0.5+incompatible // indirect
 	github.com/pkg/errors v0.9.1
 	github.com/prometheus/client_golang v1.0.0
 	github.com/prometheus/common v0.4.1
@@ -81,3 +80,5 @@ require (
 	k8s.io/client-go v12.0.0+incompatible
 	k8s.io/klog v0.3.3
 )
+
+go 1.13
diff --git a/pkg/executor/api.go b/pkg/executor/api.go
index 8947c6e6..b52777f7 100644
--- a/pkg/executor/api.go
+++ b/pkg/executor/api.go
@@ -36,7 +36,7 @@ import (
 	"github.com/fission/fission/pkg/executor/client"
 )
 
-func (executor *Executor) getServiceForFunctionApi(w http.ResponseWriter, r *http.Request) {
+func (executor *Executor) getServiceForFunctionAPI(w http.ResponseWriter, r *http.Request) {
 	body, err := ioutil.ReadAll(r.Body)
 	if err != nil {
 		http.Error(w, "Failed to read request", http.StatusInternalServerError)
@@ -94,7 +94,14 @@ func (executor *Executor) getServiceForFunctionApi(w http.ResponseWriter, r *htt
 		return
 	}
 
-	w.Write([]byte(serviceName))
+	_, err = w.Write([]byte(serviceName))
+	if err != nil {
+		executor.logger.Error(
+			"error writing HTTP response",
+			zap.String("function", m.Name),
+			zap.Error(err),
+		)
+	}
 }
 
 // getServiceForFunction first checks if this function's service is cached, if yes, it validates the address.
@@ -119,13 +126,12 @@ func (executor *Executor) getServiceForFunction(fn *fv1.Function) (string, error
 		if et.IsValid(fsvc) {
 			// Cached, return svc address
 			return fsvc.Address, nil
-		} else {
-			executor.logger.Debug("deleting cache entry for invalid address",
-				zap.String("function_name", fn.ObjectMeta.Name),
-				zap.String("function_namespace", fn.ObjectMeta.Namespace),
-				zap.String("address", fsvc.Address))
-			et.DeleteFuncSvcFromCache(fsvc)
 		}
+		executor.logger.Debug("deleting cache entry for invalid address",
+			zap.String("function_name", fn.ObjectMeta.Name),
+			zap.String("function_namespace", fn.ObjectMeta.Namespace),
+			zap.String("address", fsvc.Address))
+		et.DeleteFuncSvcFromCache(fsvc)
 	}
 
 	respChan := make(chan *createFuncServiceResponse)
@@ -168,7 +174,7 @@ func (executor *Executor) tapServices(w http.ResponseWriter, r *http.Request) {
 
 	errs := &multierror.Error{}
 	for _, req := range tapSvcReqs {
-		svcHost := strings.TrimPrefix(req.ServiceUrl, "http://")
+		svcHost := strings.TrimPrefix(req.ServiceURL, "http://")
 
 		et, exists := executor.executorTypes[req.FnExecutorType]
 		if !exists {
@@ -182,7 +188,7 @@ func (executor *Executor) tapServices(w http.ResponseWriter, r *http.Request) {
 		if err != nil {
 			errs = multierror.Append(errs,
 				errors.Wrapf(err, "'%v' failed to tap function '%v' in '%v' with service url '%v'",
-					req.FnMetadata.Name, req.FnMetadata.Namespace, req.ServiceUrl, req.FnExecutorType))
+					req.FnMetadata.Name, req.FnMetadata.Namespace, req.ServiceURL, req.FnExecutorType))
 		}
 	}
 
@@ -221,14 +227,15 @@ func (executor *Executor) unTapService(w http.ResponseWriter, r *http.Request) {
 
 	et := executor.executorTypes[t]
 
-	et.UnTapService(key, tapSvcReq.ServiceUrl)
+	et.UnTapService(key, tapSvcReq.ServiceURL)
 
 	w.WriteHeader(http.StatusOK)
 }
 
+// GetHandler returns an http.Handler.
 func (executor *Executor) GetHandler() http.Handler {
 	r := mux.NewRouter()
-	r.HandleFunc("/v2/getServiceForFunction", executor.getServiceForFunctionApi).Methods("POST")
+	r.HandleFunc("/v2/getServiceForFunction", executor.getServiceForFunctionAPI).Methods("POST")
 	r.HandleFunc("/v2/tapService", executor.tapService).Methods("POST") // for backward compatibility
 	r.HandleFunc("/v2/tapServices", executor.tapServices).Methods("POST")
 	r.HandleFunc("/healthz", executor.healthHandler).Methods("GET")
@@ -236,6 +243,7 @@ func (executor *Executor) GetHandler() http.Handler {
 	return r
 }
 
+// Serve starts an HTTP server.
 func (executor *Executor) Serve(port int) {
 	executor.logger.Info("starting executor API", zap.Int("port", port))
 	address := fmt.Sprintf(":%v", port)
diff --git a/pkg/executor/client/client.go b/pkg/executor/client/client.go
index 276efc84..0d7e260a 100644
--- a/pkg/executor/client/client.go
+++ b/pkg/executor/client/client.go
@@ -37,25 +37,29 @@ import (
 )
 
 type (
+	// Client is wrapper on a HTTP client.
 	Client struct {
 		logger      *zap.Logger
-		executorUrl string
-		tappedByUrl map[string]TapServiceRequest
+		executorURL string
+		tappedByURL map[string]TapServiceRequest
 		requestChan chan TapServiceRequest
 		httpClient  *http.Client
 	}
+
+	// TapServiceRequest represents
 	TapServiceRequest struct {
 		FnMetadata     metav1.ObjectMeta
 		FnExecutorType fv1.ExecutorType
-		ServiceUrl     string
+		ServiceURL     string
 	}
 )
 
-func MakeClient(logger *zap.Logger, executorUrl string) *Client {
+// MakeClient initializes and returns a Client instance.
+func MakeClient(logger *zap.Logger, executorURL string) *Client {
 	c := &Client{
 		logger:      logger.Named("executor_client"),
-		executorUrl: strings.TrimSuffix(executorUrl, "/"),
-		tappedByUrl: make(map[string]TapServiceRequest),
+		executorURL: strings.TrimSuffix(executorURL, "/"),
+		tappedByURL: make(map[string]TapServiceRequest),
 		requestChan: make(chan TapServiceRequest, 100),
 		httpClient: &http.Client{
 			Transport: &ochttp.Transport{},
@@ -65,15 +69,16 @@ func MakeClient(logger *zap.Logger, executorUrl string) *Client {
 	return c
 }
 
+// GetServiceForFunction returns the service name for a given function.
 func (c *Client) GetServiceForFunction(ctx context.Context, metadata *metav1.ObjectMeta) (string, error) {
-	executorUrl := c.executorUrl + "/v2/getServiceForFunction"
+	executorURL := c.executorURL + "/v2/getServiceForFunction"
 
 	body, err := json.Marshal(metadata)
 	if err != nil {
 		return "", errors.Wrap(err, "could not marshal request body for getting service for function")
 	}
 
-	resp, err := ctxhttp.Post(ctx, c.httpClient, executorUrl, "application/json", bytes.NewReader(body))
+	resp, err := ctxhttp.Post(ctx, c.httpClient, executorURL, "application/json", bytes.NewReader(body))
 	if err != nil {
 		return "", errors.Wrap(err, "error posting to getting service for function")
 	}
@@ -91,12 +96,13 @@ func (c *Client) GetServiceForFunction(ctx context.Context, metadata *metav1.Obj
 	return string(svcName), nil
 }
 
-func (c *Client) UnTapService(ctx context.Context, fnMeta metav1.ObjectMeta, executorType fv1.ExecutorType, serviceUrl *url.URL) error {
-	url := c.executorUrl + "/v2/unTapService"
+// UnTapService sends a request to /v2/unTapService.
+func (c *Client) UnTapService(ctx context.Context, fnMeta metav1.ObjectMeta, executorType fv1.ExecutorType, serviceURL *url.URL) error {
+	url := c.executorURL + "/v2/unTapService"
 	tapSvc := TapServiceRequest{
 		FnMetadata:     fnMeta,
 		FnExecutorType: executorType,
-		ServiceUrl:     strings.TrimPrefix(serviceUrl.String(), "http://"),
+		ServiceURL:     strings.TrimPrefix(serviceURL.String(), "http://"),
 	}
 
 	body, err := json.Marshal(tapSvc)
@@ -122,14 +128,14 @@ func (c *Client) service() {
 	for {
 		select {
 		case svcReq := <-c.requestChan:
-			c.tappedByUrl[svcReq.ServiceUrl] = svcReq
+			c.tappedByURL[svcReq.ServiceURL] = svcReq
 		case <-ticker.C:
-			if len(c.tappedByUrl) == 0 {
+			if len(c.tappedByURL) == 0 {
 				continue
 			}
 
-			urls := c.tappedByUrl
-			c.tappedByUrl = make(map[string]TapServiceRequest)
+			urls := c.tappedByURL
+			c.tappedByURL = make(map[string]TapServiceRequest)
 
 			go func() {
 				svcReqs := []TapServiceRequest{}
@@ -147,7 +153,8 @@ func (c *Client) service() {
 	}
 }
 
-func (c *Client) TapService(fnMeta metav1.ObjectMeta, executorType fv1.ExecutorType, serviceUrl *url.URL) {
+// TapService sends a TapServiceRequest over the request channel.
+func (c *Client) TapService(fnMeta metav1.ObjectMeta, executorType fv1.ExecutorType, serviceURL *url.URL) {
 	c.requestChan <- TapServiceRequest{
 		FnMetadata: metav1.ObjectMeta{
 			Name:            fnMeta.Name,
@@ -158,19 +165,19 @@ func (c *Client) TapService(fnMeta metav1.ObjectMeta, executorType fv1.ExecutorT
 		FnExecutorType: executorType,
 		// service url is for executor to know which
 		// pod/service is currently used to serve user function.
-		ServiceUrl: serviceUrl.String(),
+		ServiceURL: serviceURL.String(),
 	}
 }
 
 func (c *Client) _tapService(tapSvcReqs []TapServiceRequest) error {
-	executorUrl := c.executorUrl + "/v2/tapServices"
+	executorURL := c.executorURL + "/v2/tapServices"
 
 	body, err := json.Marshal(tapSvcReqs)
 	if err != nil {
 		return err
 	}
 
-	resp, err := http.Post(executorUrl, "application/json", bytes.NewReader(body))
+	resp, err := http.Post(executorURL, "application/json", bytes.NewReader(body))
 	if err != nil {
 		return err
 	}
@@ -179,6 +186,5 @@ func (c *Client) _tapService(tapSvcReqs []TapServiceRequest) error {
 	if resp.StatusCode != 200 {
 		return ferror.MakeErrorFromHTTP(resp)
 	}
-
 	return nil
 }
diff --git a/pkg/executor/cms/cmscontroller.go b/pkg/executor/cms/cmscontroller.go
index 96556fa1..05a044c6 100644
--- a/pkg/executor/cms/cmscontroller.go
+++ b/pkg/executor/cms/cmscontroller.go
@@ -34,6 +34,7 @@ import (
 )
 
 type (
+	// ConfigSecretController represents a controller for configmaps and secrets
 	ConfigSecretController struct {
 		logger *zap.Logger
 
diff --git a/pkg/executor/executor.go b/pkg/executor/executor.go
index c2d3f388..d38b230c 100644
--- a/pkg/executor/executor.go
+++ b/pkg/executor/executor.go
@@ -44,6 +44,7 @@ import (
 )
 
 type (
+	// Executor defines a fission function executor.
 	Executor struct {
 		logger *zap.Logger
 
@@ -55,6 +56,7 @@ type (
 		requestChan chan *createFuncServiceRequest
 		fsCreateWg  map[string]*sync.WaitGroup
 	}
+
 	createFuncServiceRequest struct {
 		function *fv1.Function
 		respChan chan *createFuncServiceResponse
@@ -66,6 +68,7 @@ type (
 	}
 )
 
+// MakeExecutor returns an Executor for given ExecutorType(s).
 func MakeExecutor(logger *zap.Logger, cms *cms.ConfigSecretController,
 	fissionClient *crd.FissionClient, types map[fv1.ExecutorType]executortype.ExecutorType) (*Executor, error) {
 	executor := &Executor{
diff --git a/pkg/executor/executor_test.go b/pkg/executor/executor_test.go
index ccdfc0e3..cc9bdce3 100644
--- a/pkg/executor/executor_test.go
+++ b/pkg/executor/executor_test.go
@@ -102,9 +102,9 @@ func TestExecutor(t *testing.T) {
 	// run in a random namespace so we can have concurrent tests
 	// on a given cluster
 	rand.Seed(time.Now().UTC().UnixNano())
-	testId := rand.Intn(999)
-	fissionNs := fmt.Sprintf("test-%v", testId)
-	functionNs := fmt.Sprintf("test-function-%v", testId)
+	testID := rand.Intn(999)
+	fissionNs := fmt.Sprintf("test-%v", testID)
+	functionNs := fmt.Sprintf("test-function-%v", testID)
 
 	// skip test if no cluster available for testing
 	kubeconfig := os.Getenv("KUBECONFIG")
@@ -122,10 +122,20 @@ func TestExecutor(t *testing.T) {
 
 	// create the test's namespaces
 	createTestNamespace(kubeClient, fissionNs)
-	defer kubeClient.CoreV1().Namespaces().Delete(fissionNs, nil)
+	defer func() {
+		err := kubeClient.CoreV1().Namespaces().Delete(fissionNs, nil)
+		if err != nil {
+			log.Fatalf("failed to delete namespace: %v", err)
+		}
+	}()
 
 	createTestNamespace(kubeClient, functionNs)
-	defer kubeClient.CoreV1().Namespaces().Delete(functionNs, nil)
+	defer func() {
+		err := kubeClient.CoreV1().Namespaces().Delete(fissionNs, nil)
+		if err != nil {
+			log.Fatalf("failed to delete namespace: %v", err)
+		}
+	}()
 
 	config := zap.NewDevelopmentConfig()
 	config.EncoderConfig.EncodeTime = zapcore.ISO8601TimeEncoder
@@ -228,11 +238,21 @@ func TestExecutor(t *testing.T) {
 	labels := map[string]string{"functionName": f.ObjectMeta.Name}
 	var fetcherPort int32 = 30001
 	fetcherSvc := createSvc(kubeClient, functionNs, fmt.Sprintf("%v-%v", f.ObjectMeta.Name, "fetcher"), 8000, fetcherPort, labels)
-	defer kubeClient.CoreV1().Services(functionNs).Delete(fetcherSvc.ObjectMeta.Name, nil)
+	defer func() {
+		err := kubeClient.CoreV1().Services(functionNs).Delete(fetcherSvc.ObjectMeta.Name, nil)
+		if err != nil {
+			log.Fatalf("failed to delete service: %v", err)
+		}
+	}()
 
 	var funcSvcPort int32 = 30002
 	functionSvc := createSvc(kubeClient, functionNs, f.ObjectMeta.Name, 8888, funcSvcPort, labels)
-	defer kubeClient.CoreV1().Services(functionNs).Delete(functionSvc.ObjectMeta.Name, nil)
+	defer func() {
+		err := kubeClient.CoreV1().Services(functionNs).Delete(functionSvc.ObjectMeta.Name, nil)
+		if err != nil {
+			log.Fatalf("failed to delete service: %v", err)
+		}
+	}()
 
 	// the main test: get a service for a given function
 	t1 := time.Now()
diff --git a/pkg/executor/executortype/newdeploy/newdeploy.go b/pkg/executor/executortype/newdeploy/newdeploy.go
index 82366535..abc62661 100644
--- a/pkg/executor/executortype/newdeploy/newdeploy.go
+++ b/pkg/executor/executortype/newdeploy/newdeploy.go
@@ -38,6 +38,7 @@ import (
 	"github.com/fission/fission/pkg/utils"
 )
 
+// Deployment Constants
 const (
 	DeploymentKind    = "Deployment"
 	DeploymentVersion = "apps/v1"
diff --git a/pkg/executor/executortype/newdeploy/newdeploymgr.go b/pkg/executor/executortype/newdeploy/newdeploymgr.go
index a85a9fc6..aa72a915 100644
--- a/pkg/executor/executortype/newdeploy/newdeploymgr.go
+++ b/pkg/executor/executortype/newdeploy/newdeploymgr.go
@@ -52,6 +52,7 @@ import (
 var _ executortype.ExecutorType = &NewDeploy{}
 
 type (
+	// NewDeploy represents an ExecutorType
 	NewDeploy struct {
 		logger *zap.Logger
 
@@ -78,6 +79,7 @@ type (
 	}
 )
 
+// MakeNewDeploy initializes and returns an instance of NewDeploy.
 func MakeNewDeploy(
 	logger *zap.Logger,
 	fissionClient *crd.FissionClient,
@@ -128,16 +130,19 @@ func MakeNewDeploy(
 	return nd
 }
 
+// Run start the function and environment controller along with an object reaper.
 func (deploy *NewDeploy) Run(ctx context.Context) {
 	go deploy.funcController.Run(ctx.Done())
 	go deploy.envController.Run(ctx.Done())
 	go deploy.idleObjectReaper()
 }
 
+// GetTypeName returns the executor type name.
 func (deploy *NewDeploy) GetTypeName() fv1.ExecutorType {
 	return fv1.ExecutorTypeNewdeploy
 }
 
+// GetFuncSvc returns a function service; error otherwise.
 func (deploy *NewDeploy) GetFuncSvc(ctx context.Context, fn *fv1.Function) (*fscache.FuncSvc, error) {
 	// TODO: client-go doesn't support to pass in context.
 	//  Once it supports context, we should change the signature of method.
@@ -145,23 +150,28 @@ func (deploy *NewDeploy) GetFuncSvc(ctx context.Context, fn *fv1.Function) (*fsc
 	return deploy.createFunction(fn)
 }
 
+// GetFuncSvcFromCache returns a function service from cache; error otherwise.
 func (deploy *NewDeploy) GetFuncSvcFromCache(fn *fv1.Function) (*fscache.FuncSvc, error) {
 	return deploy.fsCache.GetByFunction(&fn.ObjectMeta)
 }
 
+// DeleteFuncSvcFromCache deletes a function service from cache.
 func (deploy *NewDeploy) DeleteFuncSvcFromCache(fsvc *fscache.FuncSvc) {
 	deploy.fsCache.DeleteEntry(fsvc)
 }
 
+// UnTapService has not been implemented for NewDeployment.
 func (deploy *NewDeploy) UnTapService(key string, svcHost string) {
 	// Not Implemented for NewDeployment. Will be used when support of concurrent specialization of same function is added.
 }
 
+// GetTotalAvailable has not been implemented for NewDeployment.
 func (deploy *NewDeploy) GetTotalAvailable(fn *fv1.Function) int {
 	// Not Implemented for NewDeployment. Will be used when support of concurrent specialization of same function is added.
 	return 0
 }
 
+// TapService makes a TouchByAddress request to the cache.
 func (deploy *NewDeploy) TapService(svcHost string) error {
 	err := deploy.fsCache.TouchByAddress(svcHost)
 	if err != nil {
@@ -252,6 +262,7 @@ func (deploy *NewDeploy) RefreshFuncPods(logger *zap.Logger, f fv1.Function) err
 	return nil
 }
 
+// AdoptExistingResources attempts to adopt resources for functions in all namespaces.
 func (deploy *NewDeploy) AdoptExistingResources() {
 	fnList, err := deploy.fissionClient.CoreV1().Functions(metav1.NamespaceAll).List(metav1.ListOptions{})
 	if err != nil {
@@ -281,6 +292,7 @@ func (deploy *NewDeploy) AdoptExistingResources() {
 	wg.Wait()
 }
 
+// CleanupOldExecutorObjects cleans orphaned resources.
 func (deploy *NewDeploy) CleanupOldExecutorObjects() {
 	deploy.logger.Info("Newdeploy starts to clean orphaned resources", zap.String("instanceID", deploy.instanceID))
 
@@ -470,7 +482,7 @@ func (deploy *NewDeploy) fnCreate(fn *fv1.Function) (*fscache.FuncSvc, error) {
 	svc, err := deploy.createOrGetSvc(deployLabels, deployAnnotations, objName, ns)
 	if err != nil {
 		deploy.logger.Error("error creating service", zap.Error(err), zap.String("service", objName))
-		go deploy.cleanupNewdeploy(ns, objName)
+		go deploy.cleanupNewdeploy(ns, objName) //nolint: errcheck
 		return nil, errors.Wrapf(err, "error creating service %v", objName)
 	}
 	svcAddress := fmt.Sprintf("%v.%v", svc.Name, svc.Namespace)
@@ -478,14 +490,14 @@ func (deploy *NewDeploy) fnCreate(fn *fv1.Function) (*fscache.FuncSvc, error) {
 	depl, err := deploy.createOrGetDeployment(fn, env, objName, deployLabels, deployAnnotations, ns)
 	if err != nil {
 		deploy.logger.Error("error creating deployment", zap.Error(err), zap.String("deployment", objName))
-		go deploy.cleanupNewdeploy(ns, objName)
+		go deploy.cleanupNewdeploy(ns, objName) //nolint: errcheck
 		return nil, errors.Wrapf(err, "error creating deployment %v", objName)
 	}
 
 	hpa, err := deploy.createOrGetHpa(objName, &fn.Spec.InvokeStrategy.ExecutionStrategy, depl, deployLabels, deployAnnotations)
 	if err != nil {
 		deploy.logger.Error("error creating HPA", zap.Error(err), zap.String("hpa", objName))
-		go deploy.cleanupNewdeploy(ns, objName)
+		go deploy.cleanupNewdeploy(ns, objName) //nolint: errcheck
 		return nil, errors.Wrapf(err, "error creating the HPA %v", objName)
 	}
 
@@ -727,7 +739,7 @@ func (deploy *NewDeploy) fnDelete(fn *fv1.Function) error {
 	_, err = deploy.fsCache.DeleteOld(fsvc, time.Second*0)
 	if err != nil {
 		multierr = multierror.Append(multierr,
-			errors.Wrap(err, fmt.Sprintf("error deleting the function from cache")))
+			errors.Wrap(err, "error deleting the function from cache"))
 	}
 
 	// to support backward compatibility, if the function was created in default ns, we fall back to creating the
diff --git a/pkg/executor/executortype/poolmgr/gp.go b/pkg/executor/executortype/poolmgr/gp.go
index 38cfd456..2f8a0d30 100644
--- a/pkg/executor/executortype/poolmgr/gp.go
+++ b/pkg/executor/executortype/poolmgr/gp.go
@@ -49,6 +49,7 @@ import (
 )
 
 type (
+	// GenericPool represents a generic environment pool
 	GenericPool struct {
 		logger                   *zap.Logger
 		env                      *fv1.Environment
@@ -60,19 +61,20 @@ type (
 		fsCache                  *fscache.FunctionServiceCache // cache funcSvc's by function, address and podname
 		useSvc                   bool                          // create k8s service for specialized pods
 		useIstio                 bool
-		poolInstanceId           string           // small random string to uniquify pod names
 		runtimeImagePullPolicy   apiv1.PullPolicy // pull policy for generic pool to created env deployment
 		kubernetesClient         *kubernetes.Clientset
 		fissionClient            *crd.FissionClient
-		instanceId               string // poolmgr instance id
 		fetcherConfig            *fetcherConfig.Config
 		stopReadyPodControllerCh chan struct{}
 		readyPodController       cache.Controller
 		readyPodIndexer          cache.Indexer
 		readyPodQueue            workqueue.RateLimitingInterface
+		poolInstanceID           string // small random string to uniquify pod names
+		instanceID               string // poolmgr instance id
 	}
 )
 
+// MakeGenericPool returns an instance of GenericPool
 func MakeGenericPool(
 	logger *zap.Logger,
 	fissionClient *crd.FissionClient,
@@ -83,7 +85,7 @@ func MakeGenericPool(
 	functionNamespace string,
 	fsCache *fscache.FunctionServiceCache,
 	fetcherConfig *fetcherConfig.Config,
-	instanceId string,
+	instanceID string,
 	enableIstio bool) (*GenericPool, error) {
 
 	gpLogger := logger.Named("generic_pool")
@@ -112,12 +114,12 @@ func MakeGenericPool(
 		functionNamespace:        functionNamespace,
 		podReadyTimeout:          podReadyTimeout,
 		fsCache:                  fsCache,
-		poolInstanceId:           uniuri.NewLen(8),
 		fetcherConfig:            fetcherConfig,
-		instanceId:               instanceId,
 		useSvc:                   false,       // defaults off -- svc takes a second or more to become routable, slowing cold start
 		useIstio:                 enableIstio, // defaults off -- istio integration requires pod relabeling and it takes a second or more to become routable, slowing cold start
 		stopReadyPodControllerCh: make(chan struct{}),
+		poolInstanceID:           uniuri.NewLen(8),
+		instanceID:               instanceID,
 	}
 
 	gp.runtimeImagePullPolicy = utils.GetImagePullPolicy(os.Getenv("RUNTIME_IMAGE_PULL_POLICY"))
@@ -155,7 +157,7 @@ func (gp *GenericPool) getEnvironmentPoolLabels() map[string]string {
 
 func (gp *GenericPool) getDeployAnnotations() map[string]string {
 	return map[string]string{
-		fv1.EXECUTOR_INSTANCEID_LABEL: gp.instanceId,
+		fv1.EXECUTOR_INSTANCEID_LABEL: gp.instanceID,
 	}
 }
 
@@ -261,35 +263,43 @@ func (gp *GenericPool) scheduleDeletePod(name string) {
 		// cleaned up.  (We need a better solutions for both those things; log
 		// aggregation and storage will help.)
 		gp.logger.Error("error in pod - scheduling cleanup", zap.String("pod", name))
-		gp.kubernetesClient.CoreV1().Pods(gp.namespace).Delete(name, nil)
+		err := gp.kubernetesClient.CoreV1().Pods(gp.namespace).Delete(name, nil)
+		if err != nil {
+			gp.logger.Error(
+				"error deleting pod",
+				zap.String("name", name),
+				zap.String("namespace", gp.namespace),
+				zap.Error(err),
+			)
+		}
 	}()
 }
 
+// IsIPv6 validates if the podIP follows to IPv6 protocol
 func IsIPv6(podIP string) bool {
 	ip := net.ParseIP(podIP)
 	return ip != nil && strings.Contains(podIP, ":")
 }
 
-func (gp *GenericPool) getFetcherUrl(podIP string) string {
-	testUrl := os.Getenv("TEST_FETCHER_URL")
-	if len(testUrl) != 0 {
+func (gp *GenericPool) getFetcherURL(podIP string) string {
+	testURL := os.Getenv("TEST_FETCHER_URL")
+	if len(testURL) != 0 {
 		// it takes a second or so for the test service to
 		// become routable once a pod is relabeled. This is
 		// super hacky, but only runs in unit tests.
 		time.Sleep(5 * time.Second)
-		return testUrl
+		return testURL
 	}
+
 	isv6 := IsIPv6(podIP)
-	var baseUrl string
+	var baseURL string
 
 	if isv6 { // We use bracket if the IP is in IPv6.
-		baseUrl = fmt.Sprintf("http://[%v]:8000/", podIP)
+		baseURL = fmt.Sprintf("http://[%v]:8000/", podIP)
 	} else {
-		baseUrl = fmt.Sprintf("http://%v:8000/", podIP)
+		baseURL = fmt.Sprintf("http://%v:8000/", podIP)
 	}
-
-	return baseUrl
-
+	return baseURL
 }
 
 // specializePod chooses a pod, copies the required user-defined function to that pod
@@ -308,8 +318,8 @@ func (gp *GenericPool) specializePod(ctx context.Context, pod *apiv1.Pod, fn *fv
 	}
 
 	// tell fetcher to get the function.
-	fetcherUrl := gp.getFetcherUrl(podIP)
-	gp.logger.Info("calling fetcher to copy function", zap.String("function", fn.ObjectMeta.Name), zap.String("url", fetcherUrl))
+	fetcherURL := gp.getFetcherURL(podIP)
+	gp.logger.Info("calling fetcher to copy function", zap.String("function", fn.ObjectMeta.Name), zap.String("url", fetcherURL))
 
 	specializeReq := gp.fetcherConfig.NewSpecializeRequest(fn, gp.env)
 
@@ -317,7 +327,7 @@ func (gp *GenericPool) specializePod(ctx context.Context, pod *apiv1.Pod, fn *fv
 
 	// Fetcher will download user function to share volume of pod, and
 	// invoke environment specialize api for pod specialization.
-	err := fetcherClient.MakeClient(gp.logger, fetcherUrl).Specialize(ctx, &specializeReq)
+	err := fetcherClient.MakeClient(gp.logger, fetcherURL).Specialize(ctx, &specializeReq)
 	if err != nil {
 		return err
 	}
@@ -452,8 +462,8 @@ func (gp *GenericPool) createPool() error {
 
 	depl, err := gp.kubernetesClient.AppsV1().Deployments(gp.namespace).Get(deployment.Name, metav1.GetOptions{})
 	if err == nil {
-		if depl.Annotations[fv1.EXECUTOR_INSTANCEID_LABEL] != gp.instanceId {
-			deployment.Annotations[fv1.EXECUTOR_INSTANCEID_LABEL] = gp.instanceId
+		if depl.Annotations[fv1.EXECUTOR_INSTANCEID_LABEL] != gp.instanceID {
+			deployment.Annotations[fv1.EXECUTOR_INSTANCEID_LABEL] = gp.instanceID
 			// Update with the latest deployment spec. Kubernetes will trigger
 			// rolling update if spec is different from the one in the cluster.
 			depl, err = gp.kubernetesClient.AppsV1().Deployments(gp.namespace).Update(deployment)
@@ -538,7 +548,7 @@ func (gp *GenericPool) getFuncSvc(ctx context.Context, fn *fv1.Function) (*fscac
 		// Remove old versions function pods
 		for _, pod := range podList.Items {
 			// Delete pod no matter what status it is
-			gp.kubernetesClient.CoreV1().Pods(gp.namespace).Delete(pod.ObjectMeta.Name, nil)
+			gp.kubernetesClient.CoreV1().Pods(gp.namespace).Delete(pod.ObjectMeta.Name, nil) //nolint errcheck
 		}
 	}
 
diff --git a/pkg/executor/executortype/poolmgr/gpm.go b/pkg/executor/executortype/poolmgr/gpm.go
index f1f67f5b..51f31d5b 100644
--- a/pkg/executor/executortype/poolmgr/gpm.go
+++ b/pkg/executor/executortype/poolmgr/gpm.go
@@ -66,7 +66,7 @@ type (
 		fissionClient  *crd.FissionClient
 		functionEnv    *cache.Cache
 		fsCache        *fscache.FunctionServiceCache
-		instanceId     string
+		instanceID     string
 		requestChannel chan *request
 
 		enableIstio   bool
@@ -97,7 +97,7 @@ func MakeGenericPoolManager(
 	kubernetesClient *kubernetes.Clientset,
 	functionNamespace string,
 	fetcherConfig *fetcherConfig.Config,
-	instanceId string) executortype.ExecutorType {
+	instanceID string) executortype.ExecutorType {
 
 	gpmLogger := logger.Named("generic_pool_manager")
 
@@ -109,7 +109,7 @@ func MakeGenericPoolManager(
 		fissionClient:          fissionClient,
 		functionEnv:            cache.MakeCache(10*time.Second, 0),
 		fsCache:                fscache.MakeFunctionServiceCache(gpmLogger),
-		instanceId:             instanceId,
+		instanceID:             instanceID,
 		requestChannel:         make(chan *request),
 		defaultIdlePodReapTime: 2 * time.Minute,
 		fetcherConfig:          fetcherConfig,
@@ -312,7 +312,7 @@ func (gpm *GenericPoolManager) AdoptExistingResources() {
 			// avoid too many requests arrive Kubernetes API server at the same time.
 			time.Sleep(time.Duration(rand.Intn(30)) * time.Millisecond)
 
-			patch := fmt.Sprintf(`{"metadata":{"annotations":{"%v":"%v"}}}`, fv1.EXECUTOR_INSTANCEID_LABEL, gpm.instanceId)
+			patch := fmt.Sprintf(`{"metadata":{"annotations":{"%v":"%v"}}}`, fv1.EXECUTOR_INSTANCEID_LABEL, gpm.instanceID)
 			pod, err = gpm.kubernetesClient.CoreV1().Pods(pod.Namespace).Patch(pod.Name, k8sTypes.StrategicMergePatchType, []byte(patch))
 			if err != nil {
 				// just log the error since it won't affect the function serving
@@ -387,19 +387,19 @@ func (gpm *GenericPoolManager) AdoptExistingResources() {
 }
 
 func (gpm *GenericPoolManager) CleanupOldExecutorObjects() {
-	gpm.logger.Info("Poolmanager starts to clean orphaned resources", zap.String("instanceID", gpm.instanceId))
+	gpm.logger.Info("Poolmanager starts to clean orphaned resources", zap.String("instanceID", gpm.instanceID))
 
 	errs := &multierror.Error{}
 	listOpts := metav1.ListOptions{
 		LabelSelector: labels.Set(map[string]string{fv1.EXECUTOR_TYPE: string(fv1.ExecutorTypePoolmgr)}).AsSelector().String(),
 	}
 
-	err := reaper.CleanupDeployments(gpm.logger, gpm.kubernetesClient, gpm.instanceId, listOpts)
+	err := reaper.CleanupDeployments(gpm.logger, gpm.kubernetesClient, gpm.instanceID, listOpts)
 	if err != nil {
 		errs = multierror.Append(errs, err)
 	}
 
-	err = reaper.CleanupPods(gpm.logger, gpm.kubernetesClient, gpm.instanceId, listOpts)
+	err = reaper.CleanupPods(gpm.logger, gpm.kubernetesClient, gpm.instanceID, listOpts)
 	if err != nil {
 		errs = multierror.Append(errs, err)
 	}
@@ -434,7 +434,7 @@ func (gpm *GenericPoolManager) service() {
 
 				pool, err = MakeGenericPool(gpm.logger,
 					gpm.fissionClient, gpm.kubernetesClient, req.env, poolsize,
-					ns, gpm.namespace, gpm.fsCache, gpm.fetcherConfig, gpm.instanceId, gpm.enableIstio)
+					ns, gpm.namespace, gpm.fsCache, gpm.fetcherConfig, gpm.instanceID, gpm.enableIstio)
 				if err != nil {
 					req.responseChannel <- &response{error: err}
 					continue
@@ -456,7 +456,7 @@ func (gpm *GenericPoolManager) service() {
 					delete(gpm.pools, key)
 
 					// and delete the pool asynchronously.
-					go pool.destroy()
+					go pool.destroy() //nolint errcheck
 				}
 			}
 			// no response, caller doesn't wait
@@ -501,8 +501,14 @@ func (gpm *GenericPoolManager) getFunctionEnv(fn *fv1.Function) (*fv1.Environmen
 
 	// cache for future lookups
 	m := fn.ObjectMeta
-	gpm.functionEnv.Set(crd.CacheKey(&m), env)
-
+	_, err = gpm.functionEnv.Set(crd.CacheKey(&m), env)
+	if err != nil {
+		gpm.logger.Error(
+			"failed to set the key",
+			zap.String("function", fn.Name),
+			zap.Error(err),
+		)
+	}
 	return env, nil
 }
 
diff --git a/pkg/executor/fscache/functionServiceCache.go b/pkg/executor/fscache/functionServiceCache.go
index 2e4699de..75f7e0c1 100644
--- a/pkg/executor/fscache/functionServiceCache.go
+++ b/pkg/executor/fscache/functionServiceCache.go
@@ -37,6 +37,7 @@ type fscRequestType int
 
 //type executorType int
 
+// FunctionServiceCache Request Types
 const (
 	TOUCH fscRequestType = iota
 	LISTOLD
@@ -45,6 +46,7 @@ const (
 )
 
 type (
+	// FuncSvc represents a function service
 	FuncSvc struct {
 		Name              string                  // Name of object
 		Function          *metav1.ObjectMeta      // function this pod/service is for
@@ -57,6 +59,7 @@ type (
 		Atime time.Time
 	}
 
+	// FunctionServiceCache represents the function service cache
 	FunctionServiceCache struct {
 		logger            *zap.Logger
 		byFunction        *cache.Cache     // function-key -> funcSvc  : map[string]*funcSvc
@@ -66,18 +69,21 @@ type (
 
 		requestChannel chan *fscRequest
 	}
+
 	fscRequest struct {
 		requestType     fscRequestType
 		address         string
 		age             time.Duration
 		responseChannel chan *fscResponse
 	}
+
 	fscResponse struct {
 		objects []*FuncSvc
 		error
 	}
 )
 
+// IsNotFoundError checks if err is ErrorNotFound.
 func IsNotFoundError(err error) bool {
 	if fe, ok := err.(ferror.Error); ok {
 		return fe.Code == ferror.ErrorNotFound
@@ -85,6 +91,7 @@ func IsNotFoundError(err error) bool {
 	return false
 }
 
+// IsNameExistError checks if err is ErrorNameExists.
 func IsNameExistError(err error) bool {
 	if fe, ok := err.(ferror.Error); ok {
 		return fe.Code == ferror.ErrorNameExists
@@ -92,6 +99,7 @@ func IsNameExistError(err error) bool {
 	return false
 }
 
+// MakeFunctionServiceCache starts and returns an instance of FunctionServiceCache.
 func MakeFunctionServiceCache(logger *zap.Logger) *FunctionServiceCache {
 	fsc := &FunctionServiceCache{
 		logger:            logger.Named("function_service_cache"),
@@ -151,6 +159,7 @@ func (fsc *FunctionServiceCache) service() {
 	}
 }
 
+// GetByFunction gets a function service from cache using function key.
 func (fsc *FunctionServiceCache) GetByFunction(m *metav1.ObjectMeta) (*FuncSvc, error) {
 	key := crd.CacheKey(m)
 
@@ -167,6 +176,7 @@ func (fsc *FunctionServiceCache) GetByFunction(m *metav1.ObjectMeta) (*FuncSvc,
 	return &fsvcCopy, nil
 }
 
+// GetFuncSvc gets a function service from pool cache using function key.
 func (fsc *FunctionServiceCache) GetFuncSvc(m *metav1.ObjectMeta) (*FuncSvc, error) {
 	key := crd.CacheKey(m)
 
@@ -184,6 +194,7 @@ func (fsc *FunctionServiceCache) GetFuncSvc(m *metav1.ObjectMeta) (*FuncSvc, err
 	return &fsvcCopy, nil
 }
 
+// GetByFunctionUID gets a function service from cache using function UUID.
 func (fsc *FunctionServiceCache) GetByFunctionUID(uid types.UID) (*FuncSvc, error) {
 	mI, err := fsc.byFunctionUID.Get(uid)
 	if err != nil {
@@ -205,6 +216,7 @@ func (fsc *FunctionServiceCache) GetByFunctionUID(uid types.UID) (*FuncSvc, erro
 	return &fsvcCopy, nil
 }
 
+// AddFunc adds a function service to pool cache.
 func (fsc *FunctionServiceCache) AddFunc(fsvc FuncSvc) {
 	fsc.connFunctionCache.SetValue(crd.CacheKey(fsvc.Function), fsvc.Address, &fsvc)
 	now := time.Now()
@@ -214,14 +226,17 @@ func (fsc *FunctionServiceCache) AddFunc(fsvc FuncSvc) {
 	fsc.setFuncAlive(fsvc.Function.Name, string(fsvc.Function.UID), true)
 }
 
+// GetTotalAvailable returns the total number active function services.
 func (fsc *FunctionServiceCache) GetTotalAvailable(m *metav1.ObjectMeta) int {
 	return fsc.connFunctionCache.GetTotalAvailable(crd.CacheKey(m))
 }
 
+// MarkAvailable marks the value at key [function][address] as available.
 func (fsc *FunctionServiceCache) MarkAvailable(key string, svcHost string) {
 	fsc.connFunctionCache.MarkAvailable(key, svcHost)
 }
 
+// Add adds a function service to cache if it does not exist already.
 func (fsc *FunctionServiceCache) Add(fsvc FuncSvc) (*FuncSvc, error) {
 	existing, err := fsc.byFunction.Set(crd.CacheKey(fsvc.Function), &fsvc)
 	if err != nil {
@@ -268,6 +283,7 @@ func (fsc *FunctionServiceCache) Add(fsvc FuncSvc) (*FuncSvc, error) {
 	return nil, nil
 }
 
+// TouchByAddress makes a TOUCH request to given address.
 func (fsc *FunctionServiceCache) TouchByAddress(address string) error {
 	responseChannel := make(chan *fscResponse)
 	fsc.requestChannel <- &fscRequest{
@@ -294,20 +310,55 @@ func (fsc *FunctionServiceCache) _touchByAddress(address string) error {
 	return nil
 }
 
+// DeleteEntry deletes a function service from cache.
 func (fsc *FunctionServiceCache) DeleteEntry(fsvc *FuncSvc) {
-	fsc.byFunction.Delete(crd.CacheKey(fsvc.Function))
-	fsc.byAddress.Delete(fsvc.Address)
-	fsc.byFunctionUID.Delete(fsvc.Function.UID)
+	msg := "error deleting function service"
+	err := fsc.byFunction.Delete(crd.CacheKey(fsvc.Function))
+	if err != nil {
+		fsc.logger.Error(
+			msg,
+			zap.String("function", fsvc.Function.Name),
+			zap.Error(err),
+		)
+	}
+
+	err = fsc.byAddress.Delete(fsvc.Address)
+	if err != nil {
+		fsc.logger.Error(
+			msg,
+			zap.String("function", fsvc.Function.Name),
+			zap.Error(err),
+		)
+	}
+
+	err = fsc.byFunctionUID.Delete(fsvc.Function.UID)
+	if err != nil {
+		fsc.logger.Error(
+			msg,
+			zap.String("function", fsvc.Function.Name),
+			zap.Error(err),
+		)
+	}
 
 	fsc.observeFuncRunningTime(fsvc.Function.Name, string(fsvc.Function.UID), fsvc.Atime.Sub(fsvc.Ctime).Seconds())
 	fsc.observeFuncAliveTime(fsvc.Function.Name, string(fsvc.Function.UID), time.Since(fsvc.Ctime).Seconds())
 	fsc.setFuncAlive(fsvc.Function.Name, string(fsvc.Function.UID), false)
 }
 
+// DeleteFunctionSvc deletes a function service at key composed of [function][address].
 func (fsc *FunctionServiceCache) DeleteFunctionSvc(fsvc *FuncSvc) {
-	fsc.connFunctionCache.DeleteValue(crd.CacheKey(fsvc.Function), fsvc.Address)
+	err := fsc.connFunctionCache.DeleteValue(crd.CacheKey(fsvc.Function), fsvc.Address)
+	if err != nil {
+		fsc.logger.Error(
+			"error deleting function service",
+			zap.Any("function", fsvc.Function.Name),
+			zap.Any("address", fsvc.Address),
+			zap.Error(err),
+		)
+	}
 }
 
+// DeleteOld deletes aged function service entries from cache.
 func (fsc *FunctionServiceCache) DeleteOld(fsvc *FuncSvc, minAge time.Duration) (bool, error) {
 	if time.Since(fsvc.Atime) < minAge {
 		return false, nil
@@ -318,6 +369,7 @@ func (fsc *FunctionServiceCache) DeleteOld(fsvc *FuncSvc, minAge time.Duration)
 	return true, nil
 }
 
+// DeleteOldPoolCache deletes aged function service entries from pool cache.
 func (fsc *FunctionServiceCache) DeleteOldPoolCache(fsvc *FuncSvc, minAge time.Duration) (bool, error) {
 	if time.Since(fsvc.Atime) < minAge {
 		return false, nil
@@ -328,6 +380,7 @@ func (fsc *FunctionServiceCache) DeleteOldPoolCache(fsvc *FuncSvc, minAge time.D
 	return true, nil
 }
 
+// ListOld returns a list of aged function services in cache.
 func (fsc *FunctionServiceCache) ListOld(age time.Duration) ([]*FuncSvc, error) {
 	responseChannel := make(chan *fscResponse)
 	fsc.requestChannel <- &fscRequest{
@@ -339,6 +392,7 @@ func (fsc *FunctionServiceCache) ListOld(age time.Duration) ([]*FuncSvc, error)
 	return resp.objects, resp.error
 }
 
+// ListOldForPool returns a list of aged function serices in cache for pooling.
 func (fsc *FunctionServiceCache) ListOldForPool(age time.Duration) ([]*FuncSvc, error) {
 	responseChannel := make(chan *fscResponse)
 	fsc.requestChannel <- &fscRequest{
@@ -350,6 +404,7 @@ func (fsc *FunctionServiceCache) ListOldForPool(age time.Duration) ([]*FuncSvc,
 	return resp.objects, resp.error
 }
 
+// Log makes a LOG type cache request.
 func (fsc *FunctionServiceCache) Log() {
 	fsc.logger.Info("--- FunctionService Cache Contents")
 	responseChannel := make(chan *fscResponse)
diff --git a/pkg/executor/fscache/metrics.go b/pkg/executor/fscache/metrics.go
index cc8a7b39..deeb0b5f 100644
--- a/pkg/executor/fscache/metrics.go
+++ b/pkg/executor/fscache/metrics.go
@@ -47,6 +47,7 @@ func init() {
 	prometheus.MustRegister(funcIsAlive)
 }
 
+// IncreaseColdStarts increments the counter by 1.
 func (fsc *FunctionServiceCache) IncreaseColdStarts(funcname, funcuid string) {
 	coldStarts.WithLabelValues(funcname, funcuid).Inc()
 }
diff --git a/pkg/executor/reaper/reaper.go b/pkg/executor/reaper/reaper.go
index 99742ff3..a2b16fc1 100644
--- a/pkg/executor/reaper/reaper.go
+++ b/pkg/executor/reaper/reaper.go
@@ -68,7 +68,8 @@ func CleanupKubeObject(logger *zap.Logger, kubeClient *kubernetes.Clientset, kub
 	}
 }
 
-func CleanupDeployments(logger *zap.Logger, client *kubernetes.Clientset, instanceId string, listOps meta_v1.ListOptions) error {
+// CleanupDeployments deletes deployment(s) for a given instanceID
+func CleanupDeployments(logger *zap.Logger, client *kubernetes.Clientset, instanceID string, listOps meta_v1.ListOptions) error {
 	deploymentList, err := client.AppsV1().Deployments(meta_v1.NamespaceAll).List(listOps)
 	if err != nil {
 		return err
@@ -79,7 +80,7 @@ func CleanupDeployments(logger *zap.Logger, client *kubernetes.Clientset, instan
 			// Backward compatibility with older label name
 			id, ok = dep.ObjectMeta.Labels[fv1.EXECUTOR_INSTANCEID_LABEL]
 		}
-		if ok && id != instanceId {
+		if ok && id != instanceID {
 			logger.Info("cleaning up deployment", zap.String("deployment", dep.ObjectMeta.Name))
 			err := client.AppsV1().Deployments(dep.ObjectMeta.Namespace).Delete(dep.ObjectMeta.Name, &delOpt)
 			if err != nil {
@@ -94,7 +95,8 @@ func CleanupDeployments(logger *zap.Logger, client *kubernetes.Clientset, instan
 	return nil
 }
 
-func CleanupPods(logger *zap.Logger, client *kubernetes.Clientset, instanceId string, listOps meta_v1.ListOptions) error {
+// CleanupPods deletes pod(s) for a given instanceID
+func CleanupPods(logger *zap.Logger, client *kubernetes.Clientset, instanceID string, listOps meta_v1.ListOptions) error {
 	podList, err := client.CoreV1().Pods(meta_v1.NamespaceAll).List(listOps)
 	if err != nil {
 		return err
@@ -105,7 +107,7 @@ func CleanupPods(logger *zap.Logger, client *kubernetes.Clientset, instanceId st
 			// Backward compatibility with older label name
 			id, ok = pod.ObjectMeta.Labels[fv1.EXECUTOR_INSTANCEID_LABEL]
 		}
-		if ok && id != instanceId {
+		if ok && id != instanceID {
 			logger.Info("cleaning up pod", zap.String("pod", pod.ObjectMeta.Name))
 			err := client.CoreV1().Pods(pod.ObjectMeta.Namespace).Delete(pod.ObjectMeta.Name, nil)
 			if err != nil {
@@ -120,7 +122,8 @@ func CleanupPods(logger *zap.Logger, client *kubernetes.Clientset, instanceId st
 	return nil
 }
 
-func CleanupServices(logger *zap.Logger, client *kubernetes.Clientset, instanceId string, listOps meta_v1.ListOptions) error {
+// CleanupServices deletes service(s) for a given instanceID
+func CleanupServices(logger *zap.Logger, client *kubernetes.Clientset, instanceID string, listOps meta_v1.ListOptions) error {
 	svcList, err := client.CoreV1().Services(meta_v1.NamespaceAll).List(listOps)
 	if err != nil {
 		return err
@@ -131,7 +134,7 @@ func CleanupServices(logger *zap.Logger, client *kubernetes.Clientset, instanceI
 			// Backward compatibility with older label name
 			id, ok = svc.ObjectMeta.Labels[fv1.EXECUTOR_INSTANCEID_LABEL]
 		}
-		if ok && id != instanceId {
+		if ok && id != instanceID {
 			logger.Info("cleaning up service", zap.String("service", svc.ObjectMeta.Name))
 			err := client.CoreV1().Services(svc.ObjectMeta.Namespace).Delete(svc.ObjectMeta.Name, nil)
 			if err != nil {
@@ -146,7 +149,8 @@ func CleanupServices(logger *zap.Logger, client *kubernetes.Clientset, instanceI
 	return nil
 }
 
-func CleanupHpa(logger *zap.Logger, client *kubernetes.Clientset, instanceId string, listOps meta_v1.ListOptions) error {
+// CleanupHpa deletes horizontal pod autoscaler(s) for a given instanceID
+func CleanupHpa(logger *zap.Logger, client *kubernetes.Clientset, instanceID string, listOps meta_v1.ListOptions) error {
 	hpaList, err := client.AutoscalingV1().HorizontalPodAutoscalers(meta_v1.NamespaceAll).List(listOps)
 	if err != nil {
 		return err
@@ -158,7 +162,7 @@ func CleanupHpa(logger *zap.Logger, client *kubernetes.Clientset, instanceId str
 			// Backward compatibility with older label name
 			id, ok = hpa.ObjectMeta.Labels[fv1.EXECUTOR_INSTANCEID_LABEL]
 		}
-		if ok && id != instanceId {
+		if ok && id != instanceID {
 			logger.Info("cleaning up HPA", zap.String("hpa", hpa.ObjectMeta.Name))
 			err := client.AutoscalingV1().HorizontalPodAutoscalers(hpa.ObjectMeta.Namespace).Delete(hpa.ObjectMeta.Name, nil)
 			if err != nil {
@@ -171,7 +175,6 @@ func CleanupHpa(logger *zap.Logger, client *kubernetes.Clientset, instanceId str
 		}
 	}
 	return nil
-
 }
 
 // CleanupRoleBindings periodically lists rolebindings across all namespaces and removes Service Accounts from them or
diff --git a/pkg/executor/util/merge.go b/pkg/executor/util/merge.go
index 180b11cb..f529ed12 100644
--- a/pkg/executor/util/merge.go
+++ b/pkg/executor/util/merge.go
@@ -54,6 +54,7 @@ func MergeContainer(dst *apiv1.Container, src *apiv1.Container) (*apiv1.Containe
 	return &dstC, errs.ErrorOrNil()
 }
 
+// MergePodSpec updates srcPodSpec with targetPodSpec fields if not empty
 func MergePodSpec(srcPodSpec *apiv1.PodSpec, targetPodSpec *apiv1.PodSpec) (*apiv1.PodSpec, error) {
 	if targetPodSpec == nil {
 		return srcPodSpec, nil
diff --git a/pkg/executor/util/util.go b/pkg/executor/util/util.go
index cd1700b5..9889fc95 100644
--- a/pkg/executor/util/util.go
+++ b/pkg/executor/util/util.go
@@ -37,6 +37,7 @@ func ApplyImagePullSecret(secret string, podspec apiv1.PodSpec) *apiv1.PodSpec {
 	return &podspec
 }
 
+// WaitTimeout starts a wait group with timeout
 func WaitTimeout(wg *sync.WaitGroup, timeout time.Duration) {
 	waitCh := make(chan struct{})
 	go func() {