diff --git a/cmd/preupgradechecks/preupgradechecks.go b/cmd/preupgradechecks/preupgradechecks.go
index fc28742f..63825f29 100644
--- a/cmd/preupgradechecks/preupgradechecks.go
+++ b/cmd/preupgradechecks/preupgradechecks.go
@@ -218,5 +218,4 @@ func (client *PreUpgradeTaskClient) SetupRoleBindings() {
 
 	client.logger.Info("created rolebindings in default namespace",
 		zap.Strings("role_bindings", []string{types.PackageGetterRB, types.SecretConfigMapGetterRB}))
-	return
 }
diff --git a/environments/binary/env.go b/environments/binary/env.go
index 4cfd5e4e..2e66c2cd 100644
--- a/environments/binary/env.go
+++ b/environments/binary/env.go
@@ -38,10 +38,8 @@ func (e *Env) ToStringEnv() []string {
 
 func NewEnv(stringEnv []string) *Env {
 	env := &Env{}
-	if stringEnv != nil {
-		for _, rawEnvVar := range stringEnv {
-			env.SetEnv(FromString(rawEnvVar))
-		}
+	for _, rawEnvVar := range stringEnv {
+		env.SetEnv(FromString(rawEnvVar))
 	}
 	return env
 }
diff --git a/hack/travis-kube-setup.sh b/hack/travis-kube-setup.sh
index 54308e05..d2ccca67 100755
--- a/hack/travis-kube-setup.sh
+++ b/hack/travis-kube-setup.sh
@@ -14,12 +14,12 @@ then
 fi
 
 # Get staticcheck
-STATICCHECK_VERSION=2019.1.1
-if [ ! -f $TOOL_DIR/staticcheck ]
+STATICCHECK_VERSION=2019.2.3
+if [ ! -f $TOOL_DIR/staticcheck ] || (staticcheck -version | grep -v $STATICCHECK_VERSION)
 then
-    curl -LO https://github.com/dominikh/go-tools/releases/download/${STATICCHECK_VERSION}/staticcheck_linux_amd64
-    chmod +x staticcheck_linux_amd64
-    mv staticcheck_linux_amd64 $TOOL_DIR/staticcheck
+    curl -LO https://github.com/dominikh/go-tools/releases/download/${STATICCHECK_VERSION}/staticcheck_linux_amd64.tar.gz
+    tar xzvf staticcheck_linux_amd64.tar.gz
+    mv staticcheck/staticcheck $TOOL_DIR/staticcheck
 fi
 
 K8SCLI_DIR=$HOME/k8scli
diff --git a/hack/verify-staticcheck.sh b/hack/verify-staticcheck.sh
index 88cad13b..8f257c4e 100755
--- a/hack/verify-staticcheck.sh
+++ b/hack/verify-staticcheck.sh
@@ -6,12 +6,4 @@ set -o pipefail
 
 ROOT=`realpath $(dirname $0)/..`
 
-# Currently here only lists the packages that already addressed all warnings for gradual code repair.
-# That means we don't allow adding new warnings to any of package in list. And eventually, the
-# list will be replaced by find command.
-declare -a pkgs=("pkg/builder" "pkg/builder" "pkg/crd" "pkg/logger" "pkg/buildermgr" "pkg/fission-cli" "cmd/fission-cli")
-
-for pkg in "${pkgs[@]}"
-do
-    find ${ROOT}/${pkg} -type d |grep -v influxdb | xargs -I@ staticcheck @
-done
+go list ./...| grep -v vendor | grep -v "examples" | grep -v "demos" | xargs -I@ staticcheck @
diff --git a/pkg/apis/fission.io/v1/validation.go b/pkg/apis/fission.io/v1/validation.go
index 351e9a49..88b7b7d2 100644
--- a/pkg/apis/fission.io/v1/validation.go
+++ b/pkg/apis/fission.io/v1/validation.go
@@ -37,7 +37,7 @@ const (
 )
 
 var (
-	validAzureQueueName = regexp.MustCompile("^[a-z0-9][a-z0-9\\-]*[a-z0-9]$")
+	validAzureQueueName = regexp.MustCompile(`^[a-z0-9][a-z0-9\\-]*[a-z0-9]$`)
 	// Need to use raw string to support escape sequence for - & . chars
 	validKafkaTopicName = regexp.MustCompile(`^[a-zA-Z0-9][a-zA-Z0-9\-\._]*[a-zA-Z0-9]$`)
 )
diff --git a/pkg/builder/builder.go b/pkg/builder/builder.go
index d1816152..044e992b 100644
--- a/pkg/builder/builder.go
+++ b/pkg/builder/builder.go
@@ -74,7 +74,7 @@ func MakeBuilder(logger *zap.Logger, sharedVolumePath string) *Builder {
 
 func (builder *Builder) VersionHandler(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "application/json; charset=utf-8")
-	fmt.Fprintf(w, info.BuildInfo().String())
+	w.Write([]byte(info.BuildInfo().String()))
 }
 
 func (builder *Builder) Handler(w http.ResponseWriter, r *http.Request) {
diff --git a/pkg/buildermgr/pkgwatcher.go b/pkg/buildermgr/pkgwatcher.go
index df9af006..280ee350 100644
--- a/pkg/buildermgr/pkgwatcher.go
+++ b/pkg/buildermgr/pkgwatcher.go
@@ -84,7 +84,7 @@ func (pkgw *packageWatcher) build(buildCache *cache.Cache, srcpkg *fv1.Package)
 
 	// Ignore duplicate build requests
 	key := fmt.Sprintf("%v-%v", srcpkg.Metadata.Name, srcpkg.Metadata.ResourceVersion)
-	err, _ := buildCache.Set(key, srcpkg)
+	_, err := buildCache.Set(key, srcpkg)
 	if err != nil {
 		return
 	}
diff --git a/pkg/cache/cache.go b/pkg/cache/cache.go
index 387a6092..f5140789 100644
--- a/pkg/cache/cache.go
+++ b/pkg/cache/cache.go
@@ -159,7 +159,7 @@ func (c *Cache) Get(key interface{}) (interface{}, error) {
 
 // if key exists in the cache, the new value is NOT set; instead an
 // error and the old value are returned
-func (c *Cache) Set(key interface{}, value interface{}) (error, interface{}) {
+func (c *Cache) Set(key interface{}, value interface{}) (interface{}, error) {
 	respChannel := make(chan *response)
 	c.requestChannel <- &request{
 		requestType:     SET,
@@ -168,7 +168,7 @@ func (c *Cache) Set(key interface{}, value interface{}) (error, interface{}) {
 		responseChannel: respChannel,
 	}
 	resp := <-respChannel
-	return resp.error, resp.existingValue
+	return resp.existingValue, resp.error
 }
 
 func (c *Cache) Delete(key interface{}) error {
diff --git a/pkg/cache/cache_test.go b/pkg/cache/cache_test.go
index 83528b64..9941bb2e 100644
--- a/pkg/cache/cache_test.go
+++ b/pkg/cache/cache_test.go
@@ -31,9 +31,9 @@ func checkErr(err error) {
 func TestCache(t *testing.T) {
 	c := MakeCache(100*time.Millisecond, 100*time.Millisecond)
 
-	err, _ := c.Set("a", "b")
+	_, err := c.Set("a", "b")
 	checkErr(err)
-	err, _ = c.Set("p", "q")
+	_, err = c.Set("p", "q")
 	checkErr(err)
 
 	val, err := c.Get("a")
@@ -55,7 +55,7 @@ func TestCache(t *testing.T) {
 		log.Panicf("found deleted element")
 	}
 
-	err, _ = c.Set("expires", "42")
+	_, err = c.Set("expires", "42")
 	checkErr(err)
 	time.Sleep(150 * time.Millisecond)
 	_, err = c.Get("expires")
diff --git a/pkg/canaryconfigmgr/canaryConfigCache.go b/pkg/canaryconfigmgr/canaryConfigCache.go
index 4098e386..75d01619 100644
--- a/pkg/canaryconfigmgr/canaryConfigCache.go
+++ b/pkg/canaryconfigmgr/canaryConfigCache.go
@@ -68,7 +68,7 @@ func (cancelFuncMap *canaryConfigCancelFuncMap) lookup(f *metav1.ObjectMeta) (*C
 
 func (cancelFuncMap *canaryConfigCancelFuncMap) assign(f *metav1.ObjectMeta, value *CanaryProcessingInfo) error {
 	mk := keyFromMetadata(f)
-	err, _ := cancelFuncMap.cache.Set(mk, value)
+	_, err := cancelFuncMap.cache.Set(mk, value)
 	return err
 }
 
diff --git a/pkg/canaryconfigmgr/canaryConfigMgr.go b/pkg/canaryconfigmgr/canaryConfigMgr.go
index 68bae94f..dfe6417e 100644
--- a/pkg/canaryconfigmgr/canaryConfigMgr.go
+++ b/pkg/canaryconfigmgr/canaryConfigMgr.go
@@ -443,6 +443,9 @@ func (canaryCfgMgr *canaryConfigMgr) rollback(canaryConfig *fv1.CanaryConfig, tr
 	functionWeights[canaryConfig.Spec.OldFunction] = 100
 
 	err := canaryCfgMgr.updateHttpTriggerWithRetries(trigger.Metadata.Name, trigger.Metadata.Namespace, functionWeights)
+	if err != nil {
+		return err
+	}
 
 	err = canaryCfgMgr.updateCanaryConfigStatusWithRetries(canaryConfig.Metadata.Name, canaryConfig.Metadata.Namespace,
 		types.CanaryConfigStatusFailed)
diff --git a/pkg/controller/api.go b/pkg/controller/api.go
index 051b8043..8aab2875 100644
--- a/pkg/controller/api.go
+++ b/pkg/controller/api.go
@@ -53,7 +53,6 @@ type (
 		builderManagerUrl string
 		workflowApiUrl    string
 		functionNamespace string
-		useIstio          bool
 		featureStatus     map[string]string
 	}
 
@@ -167,7 +166,7 @@ func (api *API) getLogDBConfig(dbType string) logDBConfig {
 
 func (api *API) HomeHandler(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "application/json; charset=utf-8")
-	fmt.Fprintf(w, info.ApiInfo().String())
+	w.Write([]byte(info.ApiInfo().String()))
 }
 
 func (api *API) ApiVersionMismatchHandler(w http.ResponseWriter, r *http.Request) {
diff --git a/pkg/controller/client/client.go b/pkg/controller/client/client.go
index f8738a5f..6eb1ae09 100644
--- a/pkg/controller/client/client.go
+++ b/pkg/controller/client/client.go
@@ -20,13 +20,13 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"io/ioutil"
 	"net/http"
 	"strings"
 	"time"
 
+	"github.com/pkg/errors"
 	"golang.org/x/net/context/ctxhttp"
 
 	ferror "github.com/fission/fission/pkg/error"
@@ -58,9 +58,9 @@ func (c *Client) delete(relativeUrl string) error {
 	if resp.StatusCode != 200 {
 		body, err := ioutil.ReadAll(resp.Body)
 		if err != nil {
-			return errors.New("Delete failed")
+			return errors.Wrap(err, "error deleting")
 		} else {
-			return errors.New("Delete failed: " + string(body))
+			return errors.Errorf("failed to delete: %v", string(body))
 		}
 	}
 
diff --git a/pkg/controller/client/core.go b/pkg/controller/client/core.go
index 585d2dc7..e0512145 100644
--- a/pkg/controller/client/core.go
+++ b/pkg/controller/client/core.go
@@ -22,6 +22,8 @@ import (
 	"io/ioutil"
 	"net/http"
 
+	"github.com/pkg/errors"
+
 	apiv1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
@@ -84,7 +86,7 @@ func (c *Client) GetSvcURL(label string) (string, error) {
 	}
 
 	if resp == nil {
-		return "", fmt.Errorf("Failed to find service for given label: %v", label)
+		return "", errors.Errorf("failed to find service for given label: %v", label)
 	}
 
 	defer resp.Body.Close()
diff --git a/pkg/controller/functionApi.go b/pkg/controller/functionApi.go
index b78244d4..6d3b467e 100644
--- a/pkg/controller/functionApi.go
+++ b/pkg/controller/functionApi.go
@@ -106,12 +106,6 @@ func RegisterFunctionRoute(ws *restful.WebService) {
 			Returns(http.StatusOK, "Only HTTP status returned", nil))
 }
 
-func (a *API) getIstioServiceLabels(fnName string) map[string]string {
-	return map[string]string{
-		"functionName": fnName,
-	}
-}
-
 func (a *API) FunctionApiList(w http.ResponseWriter, r *http.Request) {
 	ns := a.extractQueryParamFromRequest(r, "namespace")
 	if len(ns) == 0 {
@@ -325,7 +319,7 @@ func (a *API) FunctionPodLogs(w http.ResponseWriter, r *http.Request) {
 	if len(pods) > 0 {
 		podLogsReq = a.kubernetesClient.CoreV1().Pods(ns).GetLogs(pods[0].ObjectMeta.Name, &podLogOpts)
 	} else {
-		a.respondWithError(w, errors.New("No active pods found"))
+		a.respondWithError(w, errors.New("no active pods found"))
 		return
 	}
 
@@ -341,5 +335,4 @@ func (a *API) FunctionPodLogs(w http.ResponseWriter, r *http.Request) {
 		a.respondWithError(w, err)
 		return
 	}
-	return
 }
diff --git a/pkg/executor/executor_test.go b/pkg/executor/executor_test.go
index e80350a5..182422f9 100644
--- a/pkg/executor/executor_test.go
+++ b/pkg/executor/executor_test.go
@@ -25,10 +25,8 @@ package executor
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"math/rand"
-	"net/http"
 	"os"
 	"testing"
 	"time"
@@ -99,19 +97,6 @@ func createSvc(kubeClient *kubernetes.Clientset, ns string, name string, targetP
 	return svc
 }
 
-func httpGet(url string) string {
-	resp, err := http.Get(url)
-	if err != nil {
-		log.Panicf("HTTP Get failed: URL %v: %v", url, err)
-	}
-	defer resp.Body.Close()
-	body, err := ioutil.ReadAll(resp.Body)
-	if err != nil {
-		log.Panicf("HTTP Get failed to read body: URL %v: %v", url, err)
-	}
-	return string(body)
-}
-
 func TestExecutor(t *testing.T) {
 	// run in a random namespace so we can have concurrent tests
 	// on a given cluster
diff --git a/pkg/executor/fscache/functionServiceCache.go b/pkg/executor/fscache/functionServiceCache.go
index 0d0dcb43..85554e1d 100644
--- a/pkg/executor/fscache/functionServiceCache.go
+++ b/pkg/executor/fscache/functionServiceCache.go
@@ -68,15 +68,13 @@ type (
 		requestChannel chan *fscRequest
 	}
 	fscRequest struct {
-		requestType       fscRequestType
-		address           string
-		kubernetesObjects []apiv1.ObjectReference
-		age               time.Duration
-		responseChannel   chan *fscResponse
+		requestType     fscRequestType
+		address         string
+		age             time.Duration
+		responseChannel chan *fscResponse
 	}
 	fscResponse struct {
 		objects []*FuncSvc
-		deleted bool
 		error
 	}
 )
@@ -180,7 +178,7 @@ func (fsc *FunctionServiceCache) GetByFunctionUID(uid types.UID) (*FuncSvc, erro
 }
 
 func (fsc *FunctionServiceCache) Add(fsvc FuncSvc) (*FuncSvc, error) {
-	err, existing := fsc.byFunction.Set(crd.CacheKey(fsvc.Function), &fsvc)
+	existing, err := fsc.byFunction.Set(crd.CacheKey(fsvc.Function), &fsvc)
 	if err != nil {
 		if IsNameExistError(err) {
 			f := existing.(*FuncSvc)
@@ -199,7 +197,7 @@ func (fsc *FunctionServiceCache) Add(fsvc FuncSvc) (*FuncSvc, error) {
 
 	// Add to byAddress cache. Ignore NameExists errors
 	// because of multiple-specialization. See issue #331.
-	err, _ = fsc.byAddress.Set(fsvc.Address, *fsvc.Function)
+	_, err = fsc.byAddress.Set(fsvc.Address, *fsvc.Function)
 	if err != nil {
 		if IsNameExistError(err) {
 			err = nil
@@ -211,7 +209,7 @@ func (fsc *FunctionServiceCache) Add(fsvc FuncSvc) (*FuncSvc, error) {
 
 	// Add to byFunctionUID cache. Ignore NameExists errors
 	// because of multiple-specialization. See issue #331.
-	err, _ = fsc.byFunctionUID.Set(fsvc.Function.UID, *fsvc.Function)
+	_, err = fsc.byFunctionUID.Set(fsvc.Function.UID, *fsvc.Function)
 	if err != nil {
 		if IsNameExistError(err) {
 			err = nil
@@ -257,7 +255,7 @@ func (fsc *FunctionServiceCache) DeleteEntry(fsvc *FuncSvc) {
 	fsc.byFunctionUID.Delete(fsvc.Function.UID)
 
 	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.Now().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)
 }
 
diff --git a/pkg/executor/fscache/functionServiceCache_test.go b/pkg/executor/fscache/functionServiceCache_test.go
index 1f3deb89..e0211805 100644
--- a/pkg/executor/fscache/functionServiceCache_test.go
+++ b/pkg/executor/fscache/functionServiceCache_test.go
@@ -74,12 +74,12 @@ func TestFunctionServiceCache(t *testing.T) {
 		log.Panicf("Failed to add fsvc: %v", err)
 	}
 
-	f, err := fsc.GetByFunction(fsvc.Function)
+	_, err = fsc.GetByFunction(fsvc.Function)
 	if err != nil {
 		fsc.Log()
 		log.Panicf("Failed to get fsvc: %v", err)
 	}
-	f, err = fsc.GetByFunctionUID(fsvc.Function.UID)
+	f, err := fsc.GetByFunctionUID(fsvc.Function.UID)
 	if err != nil {
 		fsc.Log()
 		log.Panicf("Failed to get fsvc by function uid: %v", err)
diff --git a/pkg/executor/fscache/metrics.go b/pkg/executor/fscache/metrics.go
index a66e1689..cc8a7b39 100644
--- a/pkg/executor/fscache/metrics.go
+++ b/pkg/executor/fscache/metrics.go
@@ -5,8 +5,6 @@ import (
 )
 
 var (
-	metricAddr = ":8080"
-
 	// funcname: the function's name
 	// funcuid: the function's version id
 	coldStarts = prometheus.NewCounterVec(
diff --git a/pkg/executor/newdeploy/newdeploy.go b/pkg/executor/newdeploy/newdeploy.go
index 6f872419..8ab24d46 100644
--- a/pkg/executor/newdeploy/newdeploy.go
+++ b/pkg/executor/newdeploy/newdeploy.go
@@ -143,10 +143,6 @@ func (deploy *NewDeploy) setupRBACObjs(deployNamespace string, fn *fv1.Function)
 	return nil
 }
 
-func (deploy *NewDeploy) getDeployment(ns, name string) (*appsv1.Deployment, error) {
-	return deploy.kubernetesClient.AppsV1().Deployments(ns).Get(name, metav1.GetOptions{})
-}
-
 func (deploy *NewDeploy) updateDeployment(deployment *appsv1.Deployment, ns string) error {
 	_, err := deploy.kubernetesClient.AppsV1().Deployments(ns).Update(deployment)
 	return err
diff --git a/pkg/executor/newdeploy/newdeploymgr.go b/pkg/executor/newdeploy/newdeploymgr.go
index 71e7fbb9..5583b2e7 100644
--- a/pkg/executor/newdeploy/newdeploymgr.go
+++ b/pkg/executor/newdeploy/newdeploymgr.go
@@ -61,7 +61,6 @@ type (
 		runtimeImagePullPolicy apiv1.PullPolicy
 		namespace              string
 		useIstio               bool
-		collectorEndpoint      string
 
 		fsCache *fscache.FunctionServiceCache // cache funcSvc's by function, address and pod name
 
@@ -523,7 +522,7 @@ func (deploy *NewDeploy) updateFunction(oldFn *fv1.Function, newFn *fv1.Function
 		}
 	}
 
-	if deployChanged == true {
+	if deployChanged {
 		env, err := deploy.fissionClient.Environments(newFn.Spec.Environment.Namespace).
 			Get(newFn.Spec.Environment.Name)
 		if err != nil {
@@ -624,20 +623,6 @@ func (deploy *NewDeploy) getDeployLabels(fnMeta metav1.ObjectMeta, envMeta metav
 	}
 }
 
-// updateKubeObjRefRV update the resource version of kubeObjectRef with
-// given kind and return error if failed to find the reference.
-func (deploy *NewDeploy) updateKubeObjRefRV(fsvc *fscache.FuncSvc, objKind string, rv string) error {
-	kubeObjs := fsvc.KubernetesObjects
-	for i, obj := range kubeObjs {
-		if obj.Kind == objKind {
-			kubeObjs[i].ResourceVersion = rv
-			return nil
-		}
-	}
-	fsvc.KubernetesObjects = kubeObjs
-	return fmt.Errorf("error finding kubernetes object reference with kind: %v", objKind)
-}
-
 // updateStatus is a function which updates status of update.
 // Current implementation only logs messages, in future it will update function status
 func (deploy *NewDeploy) updateStatus(fn *fv1.Function, err error, message string) {
diff --git a/pkg/executor/poolmgr/gp.go b/pkg/executor/poolmgr/gp.go
index 2befc087..f90657d8 100644
--- a/pkg/executor/poolmgr/gp.go
+++ b/pkg/executor/poolmgr/gp.go
@@ -154,16 +154,13 @@ func (gp *GenericPool) getDeployLabels() map[string]string {
 
 // choosePodService serializes the choosing of pods
 func (gp *GenericPool) choosePodService() {
-	for {
-		select {
-		case req := <-gp.requestChannel:
-			pod, err := gp._choosePod(req.newLabels)
-			if err != nil {
-				req.responseChannel <- &choosePodResponse{error: err}
-				continue
-			}
-			req.responseChannel <- &choosePodResponse{pod: pod}
+	for req := range gp.requestChannel {
+		pod, err := gp._choosePod(req.newLabels)
+		if err != nil {
+			req.responseChannel <- &choosePodResponse{error: err}
+			continue
 		}
+		req.responseChannel <- &choosePodResponse{pod: pod}
 	}
 }
 
@@ -287,11 +284,13 @@ func (gp *GenericPool) getFetcherUrl(podIP string) string {
 	}
 	isv6 := IsIPv6(podIP)
 	var baseUrl string
-	if isv6 == false {
-		baseUrl = fmt.Sprintf("http://%v:8000/", podIP)
-	} else if isv6 == true { // We use bracket if the IP is in IPv6.
+
+	if isv6 { // We use bracket if the IP is in IPv6.
 		baseUrl = fmt.Sprintf("http://[%v]:8000/", podIP)
+	} else {
+		baseUrl = fmt.Sprintf("http://%v:8000/", podIP)
 	}
+
 	return baseUrl
 
 }
@@ -477,7 +476,7 @@ func (gp *GenericPool) waitForReadyPod() error {
 			pod := podList.Items[0]
 			multierr := &multierror.Error{}
 			for _, cStatus := range pod.Status.ContainerStatuses {
-				if cStatus.Ready != true {
+				if !cStatus.Ready {
 					multierr = multierror.Append(multierr, errors.New(fmt.Sprintf("%v: %v", cStatus.State.Waiting.Reason, cStatus.State.Waiting.Message)))
 				}
 			}
diff --git a/pkg/executor/util/merge.go b/pkg/executor/util/merge.go
index 85bbab6b..e69144ae 100644
--- a/pkg/executor/util/merge.go
+++ b/pkg/executor/util/merge.go
@@ -120,17 +120,9 @@ func MergePodSpec(srcPodSpec *apiv1.PodSpec, targetPodSpec *apiv1.PodSpec) (*api
 		srcPodSpec.Hostname = targetPodSpec.Hostname
 	}
 
-	for _, obj := range targetPodSpec.ImagePullSecrets {
-		srcPodSpec.ImagePullSecrets = append(srcPodSpec.ImagePullSecrets, obj)
-	}
-
-	for _, obj := range targetPodSpec.Tolerations {
-		srcPodSpec.Tolerations = append(srcPodSpec.Tolerations, obj)
-	}
-
-	for _, obj := range targetPodSpec.HostAliases {
-		srcPodSpec.HostAliases = append(srcPodSpec.HostAliases, obj)
-	}
+	srcPodSpec.ImagePullSecrets = append(srcPodSpec.ImagePullSecrets, targetPodSpec.ImagePullSecrets...)
+	srcPodSpec.Tolerations = append(srcPodSpec.Tolerations, targetPodSpec.Tolerations...)
+	srcPodSpec.HostAliases = append(srcPodSpec.HostAliases, targetPodSpec.HostAliases...)
 
 	err = mergo.Merge(&srcPodSpec.NodeSelector, targetPodSpec.NodeSelector)
 	if err != nil {
diff --git a/pkg/fetcher/config/config.go b/pkg/fetcher/config/config.go
index 15533cbc..fd3c69e6 100644
--- a/pkg/fetcher/config/config.go
+++ b/pkg/fetcher/config/config.go
@@ -7,8 +7,7 @@ import (
 	"os"
 	"path/filepath"
 
-	"github.com/fission/fission/pkg/types"
-	"github.com/fission/fission/pkg/utils"
+	"github.com/pkg/errors"
 	apiv1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -16,6 +15,8 @@ import (
 	"k8s.io/client-go/kubernetes"
 
 	fv1 "github.com/fission/fission/pkg/apis/fission.io/v1"
+	"github.com/fission/fission/pkg/types"
+	"github.com/fission/fission/pkg/utils"
 )
 
 type Config struct {
@@ -30,9 +31,9 @@ type Config struct {
 	sharedSecretPath string
 	sharedCfgMapPath string
 
-	dockerRegistryAuthDomain string
-	dockerRegistryUsername   string
-	dockerRegistryPassword   string
+	// dockerRegistryAuthDomain string
+	// dockerRegistryUsername   string
+	// dockerRegistryPassword   string
 
 	serviceAccount string
 
@@ -289,7 +290,7 @@ func (cfg *Config) addFetcherToPodSpecWithCommand(podSpec *apiv1.PodSpec, mainCo
 		for _, existingContainer := range podSpec.Containers {
 			existingContainerNames = append(existingContainerNames, existingContainer.Name)
 		}
-		return fmt.Errorf("Could not find main container '%s' in given PodSpec. Found: %v",
+		return errors.Errorf("could not find main container '%s' in given PodSpec. Found: %v",
 			mainContainerName,
 			existingContainerNames)
 	}
diff --git a/pkg/fetcher/fetcher.go b/pkg/fetcher/fetcher.go
index 0531dbcf..4bb5b0be 100644
--- a/pkg/fetcher/fetcher.go
+++ b/pkg/fetcher/fetcher.go
@@ -151,7 +151,7 @@ func writeSecretOrConfigMap(dataMap map[string][]byte, dirPath string) error {
 
 func (fetcher *Fetcher) VersionHandler(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "application/json; charset=utf-8")
-	fmt.Fprintf(w, info.BuildInfo().String())
+	w.Write([]byte(info.BuildInfo().String()))
 }
 
 func (fetcher *Fetcher) FetchHandler(w http.ResponseWriter, r *http.Request) {
diff --git a/pkg/kubewatcher/kubewatcher.go b/pkg/kubewatcher/kubewatcher.go
index 7e05e6e2..bf44db7e 100644
--- a/pkg/kubewatcher/kubewatcher.go
+++ b/pkg/kubewatcher/kubewatcher.go
@@ -54,7 +54,6 @@ type (
 		kubernetesClient *kubernetes.Clientset
 		requestChannel   chan *kubeWatcherRequest
 		publisher        publisher.Publisher
-		routerUrl        string
 	}
 
 	watchSubscription struct {
diff --git a/pkg/mqtrigger/messageQueue/kafka.go b/pkg/mqtrigger/messageQueue/kafka.go
index 32114a86..6f91f79d 100644
--- a/pkg/mqtrigger/messageQueue/kafka.go
+++ b/pkg/mqtrigger/messageQueue/kafka.go
@@ -69,7 +69,7 @@ func makeKafkaMessageQueue(logger *zap.Logger, routerUrl string, mqCfg MessageQu
 		version:   kafkaVersion,
 	}
 
-	if tls, _ := strconv.ParseBool(os.Getenv("TLS_ENABLED")); tls == true {
+	if tls, _ := strconv.ParseBool(os.Getenv("TLS_ENABLED")); tls {
 		kafka.tls = true
 
 		authKeys := make(map[string][]byte)
diff --git a/pkg/mqtrigger/messageQueue/messageQueue.go b/pkg/mqtrigger/messageQueue/messageQueue.go
index 9f9597c4..79303428 100644
--- a/pkg/mqtrigger/messageQueue/messageQueue.go
+++ b/pkg/mqtrigger/messageQueue/messageQueue.go
@@ -55,7 +55,6 @@ type (
 	MessageQueueTriggerManager struct {
 		logger        *zap.Logger
 		reqChan       chan request
-		mqCfg         MessageQueueConfig
 		triggers      map[string]*triggerSubscription
 		fissionClient *crd.FissionClient
 		messageQueue  MessageQueue
diff --git a/pkg/router/functionHandler.go b/pkg/router/functionHandler.go
index 1bf6c68b..1e05d9cb 100644
--- a/pkg/router/functionHandler.go
+++ b/pkg/router/functionHandler.go
@@ -154,8 +154,7 @@ func (roundTripper RetryingRoundTripper) RoundTrip(req *http.Request) (*http.Res
 	roundTripper.addForwardedHostHeader(req)
 
 	// TODO: Keep? --> Needed for queries encoded in URL before they're stripped by the proxy
-	var originalUrl url.URL
-	originalUrl = *req.URL
+	originalUrl := *req.URL
 
 	// Iff this request needs to be recorded, we save the body
 	var postedBody string
@@ -245,7 +244,7 @@ func (roundTripper RetryingRoundTripper) RoundTrip(req *http.Request) (*http.Res
 						Body:          ioutil.NopCloser(bytes.NewBufferString(errMsg)),
 						ContentLength: int64(len(errMsg)),
 						Request:       req,
-						Header:        make(http.Header, 0),
+						Header:        make(http.Header),
 					}, nil
 				}
 				return nil, ferror.MakeError(http.StatusInternalServerError, err.Error())
diff --git a/pkg/router/functionRecorderMap.go b/pkg/router/functionRecorderMap.go
index a20a2a08..880cfbc7 100644
--- a/pkg/router/functionRecorderMap.go
+++ b/pkg/router/functionRecorderMap.go
@@ -51,7 +51,7 @@ func (frmap *functionRecorderMap) lookup(function string) (*fv1.Recorder, error)
 }
 
 func (frmap *functionRecorderMap) assign(function string, recorder *fv1.Recorder) {
-	err, _ := frmap.cache.Set(function, recorder)
+	_, err := frmap.cache.Set(function, recorder)
 	if err != nil {
 		if e, ok := err.(ferror.Error); ok && e.Code == ferror.ErrorNameExists {
 			return
diff --git a/pkg/router/functionReferenceResolver.go b/pkg/router/functionReferenceResolver.go
index 0f5c970f..7a760828 100644
--- a/pkg/router/functionReferenceResolver.go
+++ b/pkg/router/functionReferenceResolver.go
@@ -20,11 +20,8 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/pkg/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	"k8s.io/apimachinery/pkg/fields"
-	"k8s.io/apimachinery/pkg/runtime"
-	"k8s.io/apimachinery/pkg/watch"
-	"k8s.io/client-go/rest"
 	k8sCache "k8s.io/client-go/tools/cache"
 
 	fv1 "github.com/fission/fission/pkg/apis/fission.io/v1"
@@ -37,9 +34,7 @@ type (
 	functionReferenceResolver struct {
 		// FunctionReference -> function metadata
 		refCache *cache.Cache
-
-		stopCh chan struct{}
-		store  k8sCache.Store
+		store    k8sCache.Store
 	}
 
 	resolveResultType int
@@ -81,21 +76,6 @@ func makeFunctionReferenceResolver(store k8sCache.Store) *functionReferenceResol
 	return frr
 }
 
-func makeK8SCache(crdClient *rest.RESTClient) (k8sCache.Store, k8sCache.Controller) {
-	watchlist := k8sCache.NewListWatchFromClient(crdClient, "functions", metav1.NamespaceDefault, fields.Everything())
-	listWatch := &k8sCache.ListWatch{
-		ListFunc: func(options metav1.ListOptions) (runtime.Object, error) {
-			return watchlist.List(options)
-		},
-		WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
-			return watchlist.Watch(options)
-		},
-	}
-	resyncPeriod := 30 * time.Second
-	return k8sCache.NewInformer(listWatch, &fv1.Function{}, resyncPeriod,
-		k8sCache.ResourceEventHandlerFuncs{})
-}
-
 // resolve translates a trigger's function reference to a resolveResult.
 func (frr *functionReferenceResolver) resolve(trigger fv1.HTTPTrigger) (*resolveResult, error) {
 	nfr := namespacedTriggerReference{
@@ -128,7 +108,7 @@ func (frr *functionReferenceResolver) resolve(trigger fv1.HTTPTrigger) (*resolve
 		}
 
 	default:
-		return nil, fmt.Errorf("Unrecognized function reference type %v", trigger.Spec.FunctionReference.Type)
+		return nil, errors.Errorf("unrecognized function reference type %v", trigger.Spec.FunctionReference.Type)
 	}
 
 	// cache resolve result
@@ -150,7 +130,7 @@ func (frr *functionReferenceResolver) resolveByName(namespace, name string) (*re
 		return nil, err
 	}
 	if !isExist {
-		return nil, fmt.Errorf("function %v does not exist", name)
+		return nil, errors.Errorf("function %v does not exist", name)
 	}
 
 	f := obj.(*fv1.Function)
@@ -167,7 +147,7 @@ func (frr *functionReferenceResolver) resolveByName(namespace, name string) (*re
 
 func (frr *functionReferenceResolver) resolveByFunctionWeights(namespace string, fr *fv1.FunctionReference) (*resolveResult, error) {
 
-	functionMetadataMap := make(map[string]*metav1.ObjectMeta, 0)
+	functionMetadataMap := make(map[string]*metav1.ObjectMeta)
 	fnWtDistrList := make([]FunctionWeightDistribution, 0)
 	sumPrefix := 0
 
diff --git a/pkg/router/functionServiceMap.go b/pkg/router/functionServiceMap.go
index 9e99c79d..2cae359a 100644
--- a/pkg/router/functionServiceMap.go
+++ b/pkg/router/functionServiceMap.go
@@ -68,7 +68,7 @@ func (fmap *functionServiceMap) lookup(f *metav1.ObjectMeta) (*url.URL, error) {
 
 func (fmap *functionServiceMap) assign(f *metav1.ObjectMeta, serviceUrl *url.URL) {
 	mk := keyFromMetadata(f)
-	err, old := fmap.cache.Set(*mk, serviceUrl)
+	old, err := fmap.cache.Set(*mk, serviceUrl)
 	if err != nil {
 		if *serviceUrl == *(old.(*url.URL)) {
 			return
diff --git a/pkg/router/ingress.go b/pkg/router/ingress.go
index fca28620..9bd5401d 100644
--- a/pkg/router/ingress.go
+++ b/pkg/router/ingress.go
@@ -72,12 +72,12 @@ func deleteIngress(logger *zap.Logger, trigger *fv1.HTTPTrigger, kubeClient *kub
 
 func updateIngress(logger *zap.Logger, oldT *fv1.HTTPTrigger, newT *fv1.HTTPTrigger, kubeClient *kubernetes.Clientset) {
 
-	if oldT.Spec.CreateIngress == false && newT.Spec.CreateIngress == true {
+	if !oldT.Spec.CreateIngress && newT.Spec.CreateIngress {
 		createIngress(logger, newT, kubeClient)
 		return
 	}
 
-	if newT.Spec.CreateIngress == false && oldT.Spec.CreateIngress == true {
+	if !newT.Spec.CreateIngress && oldT.Spec.CreateIngress {
 		deleteIngress(logger, oldT, kubeClient)
 		return
 	}
diff --git a/pkg/router/mutablemux_test.go b/pkg/router/mutablemux_test.go
index 97ff9dd8..70edb394 100644
--- a/pkg/router/mutablemux_test.go
+++ b/pkg/router/mutablemux_test.go
@@ -47,7 +47,7 @@ func spamServer(quit chan bool) {
 	for {
 		select {
 		case <-quit:
-			break
+			return
 		default:
 			i = i + 1
 			resp, err := http.Get("http://localhost:3333")
diff --git a/pkg/router/recorderController.go b/pkg/router/recorderController.go
index e51e55f1..a299af79 100644
--- a/pkg/router/recorderController.go
+++ b/pkg/router/recorderController.go
@@ -113,7 +113,7 @@ func (rs *RecorderSet) disableRecorder(r *fv1.Recorder) {
 }
 
 func (rs *RecorderSet) updateRecorder(old *fv1.Recorder, newer *fv1.Recorder) {
-	if newer.Spec.Enabled == true {
+	if newer.Spec.Enabled {
 		rs.newRecorder(newer) // TODO: Test this
 	} else {
 		rs.disableRecorder(old)
diff --git a/pkg/router/triggerRecorderMap.go b/pkg/router/triggerRecorderMap.go
index 8284b2d2..447fb1e0 100644
--- a/pkg/router/triggerRecorderMap.go
+++ b/pkg/router/triggerRecorderMap.go
@@ -50,7 +50,7 @@ func (trmap *triggerRecorderMap) lookup(trigger string) (*fv1.Recorder, error) {
 }
 
 func (trmap *triggerRecorderMap) assign(trigger string, recorder *fv1.Recorder) {
-	err, _ := trmap.cache.Set(trigger, recorder)
+	_, err := trmap.cache.Set(trigger, recorder)
 	if err != nil {
 		if e, ok := err.(ferror.Error); ok && e.Code == ferror.ErrorNameExists {
 			return
diff --git a/pkg/storagesvc/archivePruner.go b/pkg/storagesvc/archivePruner.go
index db5aedbf..c1ec23a3 100644
--- a/pkg/storagesvc/archivePruner.go
+++ b/pkg/storagesvc/archivePruner.go
@@ -28,7 +28,7 @@ import (
 type ArchivePruner struct {
 	logger        *zap.Logger
 	crdClient     *crd.FissionClient
-	archiveChan   chan (string)
+	archiveChan   chan string
 	stowClient    *StowClient
 	pruneInterval time.Duration
 }
@@ -53,18 +53,15 @@ func MakeArchivePruner(logger *zap.Logger, stowClient *StowClient, pruneInterval
 // pruneArchives listens to archiveChannel for archive ids that need to be deleted
 func (pruner *ArchivePruner) pruneArchives() {
 	pruner.logger.Debug("listening to archiveChannel to prune archives")
-	for {
-		select {
-		case archiveID := <-pruner.archiveChan:
-			pruner.logger.Info("sending delete request for archive",
+	for archiveID := range pruner.archiveChan {
+		pruner.logger.Info("sending delete request for archive",
+			zap.String("archive_id", archiveID))
+		if err := pruner.stowClient.removeFileByID(archiveID); err != nil {
+			// logging the error and continuing with other deletions.
+			// hopefully this archive will be deleted in the next iteration.
+			pruner.logger.Error("ignoring error while deleting archive",
+				zap.Error(err),
 				zap.String("archive_id", archiveID))
-			if err := pruner.stowClient.removeFileByID(archiveID); err != nil {
-				// logging the error and continuing with other deletions.
-				// hopefully this archive will be deleted in the next iteration.
-				pruner.logger.Error("ignoring error while deleting archive",
-					zap.Error(err),
-					zap.String("archive_id", archiveID))
-			}
 		}
 	}
 }
@@ -134,8 +131,6 @@ func (pruner *ArchivePruner) getOrphanArchives() {
 	for _, archiveID = range orphanedArchives {
 		pruner.insertArchive(archiveID)
 	}
-
-	return
 }
 
 // Start starts a go routine that listens to a channel for archive IDs that need to deleted.
@@ -144,12 +139,9 @@ func (pruner *ArchivePruner) getOrphanArchives() {
 func (pruner *ArchivePruner) Start() {
 	ticker := time.NewTicker(pruner.pruneInterval * time.Minute)
 	go pruner.pruneArchives()
-	for {
-		select {
-		case <-ticker.C:
-			// This method fetches unused archive IDs and sends them to archiveChannel for deletion
-			// silencing the errors, hoping they go away in next iteration.
-			pruner.getOrphanArchives()
-		}
+	for range ticker.C {
+		// This method fetches unused archive IDs and sends them to archiveChannel for deletion
+		// silencing the errors, hoping they go away in next iteration.
+		pruner.getOrphanArchives()
 	}
 }
diff --git a/pkg/storagesvc/client/client.go b/pkg/storagesvc/client/client.go
index 6ffab97c..40814cf4 100644
--- a/pkg/storagesvc/client/client.go
+++ b/pkg/storagesvc/client/client.go
@@ -20,7 +20,6 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -30,6 +29,7 @@ import (
 	"os"
 	"strings"
 
+	"github.com/pkg/errors"
 	"go.opencensus.io/plugin/ochttp"
 	"golang.org/x/net/context/ctxhttp"
 
@@ -127,7 +127,7 @@ func (c *Client) Download(ctx context.Context, id string, filePath string) error
 	// quit if file exists
 	_, err := os.Stat(filePath)
 	if err == nil || !os.IsNotExist(err) {
-		return errors.New(fmt.Sprintf("file already exists: %v", filePath))
+		return errors.Errorf("file already exists: %v", filePath)
 	}
 
 	// create
@@ -175,7 +175,7 @@ func (c *Client) Delete(ctx context.Context, id string) error {
 	defer resp.Body.Close()
 
 	if resp.StatusCode != http.StatusOK {
-		return errors.New(fmt.Sprintf("HTTP error %v", resp.StatusCode))
+		return errors.Errorf("HTTP error %v", resp.StatusCode)
 	}
 
 	return nil
diff --git a/pkg/storagesvc/storagesvc.go b/pkg/storagesvc/storagesvc.go
index 94e719c0..d1422143 100644
--- a/pkg/storagesvc/storagesvc.go
+++ b/pkg/storagesvc/storagesvc.go
@@ -18,7 +18,6 @@ package storagesvc
 
 import (
 	"encoding/json"
-	"errors"
 	"fmt"
 	"net/http"
 	"os"
@@ -27,6 +26,7 @@ import (
 
 	"github.com/gorilla/mux"
 	_ "github.com/graymeta/stow/local"
+	"github.com/pkg/errors"
 	"go.opencensus.io/plugin/ochttp"
 	"go.uber.org/zap"
 )
@@ -109,7 +109,7 @@ func (ss *StorageService) getIdFromRequest(r *http.Request) (string, error) {
 	values := r.URL.Query()
 	ids, ok := values["id"]
 	if !ok || len(ids) == 0 {
-		return "", errors.New("Missing `id' query param")
+		return "", errors.New("missing `id' query param")
 	}
 	return ids[0], nil
 }
diff --git a/pkg/utils/rbacutils.go b/pkg/utils/rbacutils.go
index 8a370abe..34bca0d9 100644
--- a/pkg/utils/rbacutils.go
+++ b/pkg/utils/rbacutils.go
@@ -136,7 +136,7 @@ func AddSaToRoleBindingWithRetries(logger *zap.Logger, k8sClient *kubernetes.Cli
 			// someone may have deleted the object between us checking if the object is present and deciding to patch
 			// so just create the object again
 			rbObj := makeRoleBindingObj(roleBinding, roleBindingNs, role, roleKind, sa, saNamespace)
-			rbObj, err = k8sClient.RbacV1beta1().RoleBindings(roleBindingNs).Create(rbObj)
+			_, err = k8sClient.RbacV1beta1().RoleBindings(roleBindingNs).Create(rbObj)
 			if err == nil {
 				logger.Debug("created rolebinding",
 					zap.String("role_binding", roleBinding),
@@ -263,7 +263,7 @@ func SetupRoleBinding(logger *zap.Logger, k8sClient *kubernetes.Clientset, roleB
 			zap.String("role_binding", roleBinding),
 			zap.String("role_binding_namespace", roleBindingNs))
 		rbObj = makeRoleBindingObj(roleBinding, roleBindingNs, role, roleKind, sa, saNamespace)
-		rbObj, err = k8sClient.RbacV1beta1().RoleBindings(roleBindingNs).Create(rbObj)
+		_, err = k8sClient.RbacV1beta1().RoleBindings(roleBindingNs).Create(rbObj)
 		if k8serrors.IsAlreadyExists(err) {
 			logger.Debug("rolebinding already exists in namespace - adding service account to rolebinding",
 				zap.String("service_account_name", sa),
diff --git a/pkg/utils/utils.go b/pkg/utils/utils.go
index fec6fad4..d896032a 100644
--- a/pkg/utils/utils.go
+++ b/pkg/utils/utils.go
@@ -19,7 +19,6 @@ package utils
 import (
 	"crypto/sha256"
 	"encoding/hex"
-	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -29,6 +28,7 @@ import (
 	"strings"
 
 	"github.com/mholt/archiver"
+	"github.com/pkg/errors"
 	uuid "github.com/satori/go.uuid"
 	apiv1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -105,7 +105,7 @@ func FindAllGlobs(inputList []string) ([]string, error) {
 	for _, glob := range inputList {
 		f, err := filepath.Glob(glob)
 		if err != nil {
-			return nil, fmt.Errorf("Invalid glob %v: %v", glob, err)
+			return nil, errors.Errorf("invalid glob %v: %v", glob, err)
 		}
 		files = append(files, f...)
 	}
diff --git a/pkg/v1/types.go b/pkg/v1/types.go
index 8e000cb2..ad3db03e 100644
--- a/pkg/v1/types.go
+++ b/pkg/v1/types.go
@@ -99,24 +99,24 @@ type (
 	errorCode int
 )
 
-const (
-	ErrorInternal = iota
-
-	ErrorNotAuthorized
-	ErrorNotFound
-	ErrorNameExists
-	ErrorInvalidArgument
-	ErrorNoSpace
-	ErrorNotImplmented
-)
-
-// must match order and len of the above const
-var errorDescriptions = []string{
-	"Internal error",
-	"Not authorized",
-	"Resource not found",
-	"Resource exists",
-	"Invalid argument",
-	"No space",
-	"Not implemented",
-}
+//const (
+//	ErrorInternal = iota
+//
+//	ErrorNotAuthorized
+//	ErrorNotFound
+//	ErrorNameExists
+//	ErrorInvalidArgument
+//	ErrorNoSpace
+//	ErrorNotImplmented
+//)
+//
+//// must match order and len of the above const
+//var errorDescriptions = []string{
+//	"Internal error",
+//	"Not authorized",
+//	"Resource not found",
+//	"Resource exists",
+//	"Invalid argument",
+//	"No space",
+//	"Not implemented",
+//}
diff --git a/test/benchmark/picasso.go b/test/benchmark/picasso.go
index 90948981..1e1eff6e 100644
--- a/test/benchmark/picasso.go
+++ b/test/benchmark/picasso.go
@@ -72,7 +72,6 @@ func generateContinuousSeries(file string) chart.Series {
 
 	reader := bufio.NewReader(f)
 
-	var points []*MetricPoint
 	var xVals []float64
 	var yVals []float64
 
@@ -95,8 +94,6 @@ func generateContinuousSeries(file string) chart.Series {
 			continue
 		}
 
-		points = append(points, point)
-
 		if initTime == nil {
 			initTime = &point.Data.Time
 		}
@@ -119,7 +116,7 @@ func generateContinuousSeries(file string) chart.Series {
 
 func generateChart(title string, file string, format chart.RendererProvider, series []chart.Series) error {
 	if series == nil {
-		return errors.New("Series cannot be nil")
+		return errors.New("series cannot be nil")
 	}
 
 	cs := chart.ConcatSeries(series)
@@ -190,16 +187,13 @@ func listJsonFiles(path string) ([]string, error) {
 		if err != nil {
 			return err
 		}
-
 		if strings.HasSuffix(path, ".json") && !info.IsDir() {
 			files = append(files, path)
-			return nil
 		}
-
 		return nil
 	})
 
-	return files, nil
+	return files, err
 }
 
 func main() {