chore: Fix linter findings for `revive:enforce-slice-style` in `plugins/inputs/[a-d]*` and `plugins/common` (#16161)

plugins/common/jolokia2/client.go

@@ -221,7 +221,7 @@ func makeReadResponses(jresponses []jolokiaResponse) []ReadResponse {
 		rrequest := ReadRequest{
 			Mbean:      jr.Request.Mbean,
 			Path:       jr.Request.Path,
-			Attributes: []string{},
+			Attributes: make([]string, 0),
 		}
 
 		attrValue := jr.Request.Attribute

plugins/common/jolokia2/gatherer.go

@@ -200,7 +200,7 @@ func makeReadRequests(metrics []Metric) []ReadRequest {
 		if len(metric.Paths) == 0 {
 			requests = append(requests, ReadRequest{
 				Mbean:      metric.Mbean,
-				Attributes: []string{},
+				Attributes: make([]string, 0),
 			})
 		} else {
 			attributes := make(map[string][]string)

plugins/common/jolokia2/gatherer_test.go

@@ -19,7 +19,7 @@ func TestJolokia2_makeReadRequests(t *testing.T) {
 			expected: []ReadRequest{
 				{
 					Mbean:      "test:foo=bar",
-					Attributes: []string{},
+					Attributes: make([]string, 0),
 				},
 			},
 		}, {

plugins/common/jolokia2/metric.go

@@ -115,13 +115,13 @@ func (m Metric) MatchAttributeAndPath(attribute, innerPath string) bool {
 func parseMbeanObjectName(name string) (string, []string) {
 	index := strings.Index(name, ":")
 	if index == -1 {
-		return name, []string{}
+		return name, nil
 	}
 
 	domain := name[:index]
 
 	if index+1 > len(name) {
-		return domain, []string{}
+		return domain, nil
 	}
 
 	return domain, strings.Split(name[index+1:], ",")

plugins/common/opcua/input/input_client_test.go

@@ -126,7 +126,6 @@ func TestValidateOPCTags(t *testing.T) {
 						TagsSlice:      [][]string{{"t1", "v1"}, {"t3", "v2"}},
 					},
 				},
-				Groups: []NodeGroupSettings{},
 			},
 			nil,
 		},
@@ -150,7 +149,6 @@ func TestValidateOPCTags(t *testing.T) {
 						TagsSlice:      [][]string{{"t1", "bar"}, {"t2", "v2"}},
 					},
 				},
-				Groups: []NodeGroupSettings{},
 			},
 			nil,
 		},
@@ -158,7 +156,6 @@ func TestValidateOPCTags(t *testing.T) {
 			"different metric names",
 			InputClientConfig{
 				MetricName: "mn",
-				RootNodes:  []NodeSettings{},
 				Groups: []NodeGroupSettings{
 					{
 						MetricName: "mn",
@@ -208,7 +205,6 @@ func TestValidateOPCTags(t *testing.T) {
 						TagsSlice:      [][]string{{"t1", "v1"}, {"t2", "v2"}},
 					},
 				},
-				Groups: []NodeGroupSettings{},
 			},
 			nil,
 		},
@@ -239,7 +235,6 @@ func TestNewNodeMetricMappingTags(t *testing.T) {
 				Namespace:      "2",
 				IdentifierType: "s",
 				Identifier:     "h",
-				TagsSlice:      [][]string{},
 			},
 			groupTags:    map[string]string{},
 			expectedTags: map[string]string{},
@@ -265,7 +260,6 @@ func TestNewNodeMetricMappingTags(t *testing.T) {
 				Namespace:      "2",
 				IdentifierType: "s",
 				Identifier:     "h",
-				TagsSlice:      [][]string{},
 			},
 			groupTags:    map[string]string{"t1": "v1"},
 			expectedTags: map[string]string{"t1": "v1"},
@@ -313,7 +307,6 @@ func TestNewNodeMetricMappingIdStrInstantiated(t *testing.T) {
 		Namespace:      "2",
 		IdentifierType: "s",
 		Identifier:     "h",
-		TagsSlice:      [][]string{},
 	}, map[string]string{})
 	require.NoError(t, err)
 	require.Equal(t, "ns=2;s=h", nmm.idStr)
@@ -335,7 +328,6 @@ func TestValidateNodeToAdd(t *testing.T) {
 					Namespace:      "2",
 					IdentifierType: "s",
 					Identifier:     "hf",
-					TagsSlice:      [][]string{},
 				}, map[string]string{})
 				require.NoError(t, err)
 				return nmm
@@ -351,7 +343,6 @@ func TestValidateNodeToAdd(t *testing.T) {
 					Namespace:      "2",
 					IdentifierType: "s",
 					Identifier:     "hf",
-					TagsSlice:      [][]string{},
 				}, map[string]string{})
 				require.NoError(t, err)
 				return nmm
@@ -367,7 +358,6 @@ func TestValidateNodeToAdd(t *testing.T) {
 					Namespace:      "",
 					IdentifierType: "s",
 					Identifier:     "hf",
-					TagsSlice:      [][]string{},
 				}, map[string]string{})
 				require.NoError(t, err)
 				return nmm
@@ -383,7 +373,6 @@ func TestValidateNodeToAdd(t *testing.T) {
 					Namespace:      "2",
 					IdentifierType: "",
 					Identifier:     "hf",
-					TagsSlice:      [][]string{},
 				}, map[string]string{})
 				require.NoError(t, err)
 				return nmm
@@ -399,7 +388,6 @@ func TestValidateNodeToAdd(t *testing.T) {
 					Namespace:      "2",
 					IdentifierType: "j",
 					Identifier:     "hf",
-					TagsSlice:      [][]string{},
 				}, map[string]string{})
 				require.NoError(t, err)
 				return nmm
@@ -433,7 +421,6 @@ func TestValidateNodeToAdd(t *testing.T) {
 					Namespace:      "2",
 					IdentifierType: "i",
 					Identifier:     "hf",
-					TagsSlice:      [][]string{},
 				}, map[string]string{})
 				require.NoError(t, err)
 				return nmm
@@ -461,7 +448,6 @@ func TestValidateNodeToAdd(t *testing.T) {
 					Namespace:      "2",
 					IdentifierType: idT,
 					Identifier:     idV,
-					TagsSlice:      [][]string{},
 				}, map[string]string{})
 				require.NoError(t, err)
 				return nmm
@@ -499,7 +485,6 @@ func TestInitNodeMetricMapping(t *testing.T) {
 						TagsSlice:      [][]string{{"t1", "v1"}},
 					},
 				},
-				Groups: []NodeGroupSettings{},
 			},
 			expected: []NodeMetricMapping{
 				{
@@ -543,7 +528,6 @@ func TestInitNodeMetricMapping(t *testing.T) {
 								TagsSlice:  [][]string{{"t2", "v2"}},
 							},
 						},
-						TagsSlice: [][]string{},
 					},
 				},
 			},
@@ -580,7 +564,6 @@ func TestInitNodeMetricMapping(t *testing.T) {
 			config: InputClientConfig{
 				MetricName: "testmetric",
 				Timestamp:  TimestampSourceTelegraf,
-				RootNodes:  []NodeSettings{},
 				Groups: []NodeGroupSettings{
 					{
 						MetricName:     "groupmetric",
@@ -593,7 +576,6 @@ func TestInitNodeMetricMapping(t *testing.T) {
 								TagsSlice:  [][]string{{"t2", "v2"}},
 							},
 						},
-						TagsSlice: [][]string{},
 					},
 				},
 			},
@@ -618,7 +600,6 @@ func TestInitNodeMetricMapping(t *testing.T) {
 			config: InputClientConfig{
 				MetricName: "testmetric",
 				Timestamp:  TimestampSourceTelegraf,
-				RootNodes:  []NodeSettings{},
 				Groups: []NodeGroupSettings{
 					{
 						MetricName:     "groupmetric",
@@ -632,7 +613,6 @@ func TestInitNodeMetricMapping(t *testing.T) {
 								DefaultTags: map[string]string{"t3": "v3"},
 							},
 						},
-						TagsSlice: [][]string{},
 					},
 				},
 			},
@@ -668,7 +648,6 @@ func TestInitNodeMetricMapping(t *testing.T) {
 						DefaultTags:    map[string]string{"t3": "v3"},
 					},
 				},
-				Groups: []NodeGroupSettings{},
 			},
 			expected: []NodeMetricMapping{
 				{

plugins/common/opcua/opcua_util.go

@@ -151,16 +151,15 @@ func pemBlockForKey(priv interface{}) (*pem.Block, error) {
 }
 
 func (o *OpcUAClient) generateClientOpts(endpoints []*ua.EndpointDescription) ([]opcua.Option, error) {
-	opts := []opcua.Option{}
 	appuri := "urn:telegraf:gopcua:client"
 	appname := "Telegraf"
 
 	// ApplicationURI is automatically read from the cert so is not required if a cert if provided
-	opts = append(opts,
+	opts := []opcua.Option{
 		opcua.ApplicationURI(appuri),
 		opcua.ApplicationName(appname),
 		opcua.RequestTimeout(time.Duration(o.Config.RequestTimeout)),
-	)
+	}
 
 	if o.Config.SessionTimeout != 0 {
 		opts = append(opts, opcua.SessionTimeout(time.Duration(o.Config.SessionTimeout)))

plugins/common/shim/config.go

@@ -153,17 +153,17 @@ func DefaultImportedPlugins() config {
 	}
 	for name := range inputs.Inputs {
 		log.Println("No config found. Loading default config for plugin", name)
-		conf.Inputs[name] = []toml.Primitive{}
+		conf.Inputs[name] = make([]toml.Primitive, 0)
 		return conf
 	}
 	for name := range processors.Processors {
 		log.Println("No config found. Loading default config for plugin", name)
-		conf.Processors[name] = []toml.Primitive{}
+		conf.Processors[name] = make([]toml.Primitive, 0)
 		return conf
 	}
 	for name := range outputs.Outputs {
 		log.Println("No config found. Loading default config for plugin", name)
-		conf.Outputs[name] = []toml.Primitive{}
+		conf.Outputs[name] = make([]toml.Primitive, 0)
 		return conf
 	}
 	return conf

plugins/common/starlark/starlark.go

@@ -35,7 +35,7 @@ func (s *Common) GetState() interface{} {
 	// Return the actual byte-type instead of nil allowing the persister
 	// to guess instantiate variable of the appropriate type
 	if s.state == nil {
-		return []byte{}
+		return make([]byte, 0)
 	}
 
 	// Convert the starlark dict into a golang dictionary for serialization
@@ -65,7 +65,7 @@ func (s *Common) GetState() interface{} {
 	var buf bytes.Buffer
 	if err := gob.NewEncoder(&buf).Encode(state); err != nil {
 		s.Log.Errorf("encoding state failed: %v", err)
-		return []byte{}
+		return make([]byte, 0)
 	}
 
 	return buf.Bytes()

plugins/common/tls/utils.go

@@ -39,8 +39,7 @@ func Ciphers() (secure, insecure []string) {
 // ParseCiphers returns a `[]uint16` by received `[]string` key that represents ciphers from crypto/tls.
 // If some of ciphers in received list doesn't exists  ParseCiphers returns nil with error
 func ParseCiphers(ciphers []string) ([]uint16, error) {
-	suites := []uint16{}
+	suites := make([]uint16, 0)
-
 	added := make(map[uint16]bool, len(ciphers))
 	for _, c := range ciphers {
 		// Handle meta-keywords

plugins/inputs/aliyuncms/aliyuncms.go

@@ -149,7 +149,7 @@ func (s *AliyunCMS) Init() error {
 			continue
 		}
 		metric.dimensionsUdObj = make(map[string]string)
-		metric.dimensionsUdArr = []map[string]string{}
+		metric.dimensionsUdArr = make([]map[string]string, 0)
 
 		// first try to unmarshal as an object
 		if err := json.Unmarshal([]byte(metric.Dimensions), &metric.dimensionsUdObj); err == nil {

plugins/inputs/aliyuncms/aliyuncms_test.go

@@ -250,8 +250,7 @@ func TestPluginMetricsInitialize(t *testing.T) {
 			accessKeySecret: "dummy",
 			metrics: []*metric{
 				{
-					MetricNames: []string{},
+					Dimensions: `{"instanceId": "i-abcdefgh123456"}`,
-					Dimensions:  `{"instanceId": "i-abcdefgh123456"}`,
 				},
 			},
 		},
@@ -263,8 +262,7 @@ func TestPluginMetricsInitialize(t *testing.T) {
 			accessKeySecret: "dummy",
 			metrics: []*metric{
 				{
-					MetricNames: []string{},
+					Dimensions: `[{"instanceId": "p-example"},{"instanceId": "q-example"}]`,
-					Dimensions:  `[{"instanceId": "p-example"},{"instanceId": "q-example"}]`,
 				},
 			},
 		},
@@ -277,8 +275,7 @@ func TestPluginMetricsInitialize(t *testing.T) {
 			expectedErrorString: `cannot parse dimensions (neither obj, nor array) "[": unexpected end of JSON input`,
 			metrics: []*metric{
 				{
-					MetricNames: []string{},
+					Dimensions: `[`,
-					Dimensions:  `[`,
 				},
 			},
 		},
@@ -344,8 +341,7 @@ func TestGatherMetric(t *testing.T) {
 	}
 
 	metric := &metric{
-		MetricNames: []string{},
+		Dimensions: `"instanceId": "i-abcdefgh123456"`,
-		Dimensions:  `"instanceId": "i-abcdefgh123456"`,
 	}
 
 	tests := []struct {
@@ -375,8 +371,7 @@ func TestGatherMetric(t *testing.T) {
 
 func TestGather(t *testing.T) {
 	m := &metric{
-		MetricNames: []string{},
+		Dimensions: `{"instanceId": "i-abcdefgh123456"}`,
-		Dimensions:  `{"instanceId": "i-abcdefgh123456"}`,
 	}
 	plugin := &AliyunCMS{
 		AccessKeyID:     "my_access_key_id",

plugins/inputs/amd_rocm_smi/amd_rocm_smi.go

@@ -180,7 +180,7 @@ func (rsmi *ROCmSMI) pollROCmSMI() ([]byte, error) {
 }
 
 func genTagsFields(gpus map[string]gpu, system map[string]sysInfo) []metric {
-	metrics := []metric{}
+	metrics := make([]metric, 0, len(gpus))
 	for cardID := range gpus {
 		if strings.Contains(cardID, "card") {
 			tags := map[string]string{

plugins/inputs/azure_monitor/azure_monitor_test.go

@@ -923,7 +923,7 @@ func TestGather_Success(t *testing.T) {
 
 	am.receiver, err = receiver.NewAzureMonitorMetricsReceiver(
 		am.SubscriptionID,
-		receiver.NewTargets(resourceTargets, []*receiver.ResourceGroupTarget{}, []*receiver.Resource{}),
+		receiver.NewTargets(resourceTargets, nil, nil),
 		azureClients,
 	)
 	require.NoError(t, err)
@@ -1010,7 +1010,7 @@ func TestGather_China_Success(t *testing.T) {
 
 	am.receiver, err = receiver.NewAzureMonitorMetricsReceiver(
 		am.SubscriptionID,
-		receiver.NewTargets(resourceTargets, []*receiver.ResourceGroupTarget{}, []*receiver.Resource{}),
+		receiver.NewTargets(resourceTargets, nil, nil),
 		azureClients,
 	)
 	require.NoError(t, err)
@@ -1043,7 +1043,7 @@ func TestGather_Government_Success(t *testing.T) {
 
 	am.receiver, err = receiver.NewAzureMonitorMetricsReceiver(
 		am.SubscriptionID,
-		receiver.NewTargets(resourceTargets, []*receiver.ResourceGroupTarget{}, []*receiver.Resource{}),
+		receiver.NewTargets(resourceTargets, nil, nil),
 		azureClients,
 	)
 	require.NoError(t, err)
@@ -1076,7 +1076,7 @@ func TestGather_Public_Success(t *testing.T) {
 
 	am.receiver, err = receiver.NewAzureMonitorMetricsReceiver(
 		am.SubscriptionID,
-		receiver.NewTargets(resourceTargets, []*receiver.ResourceGroupTarget{}, []*receiver.Resource{}),
+		receiver.NewTargets(resourceTargets, nil, nil),
 		azureClients,
 	)
 	require.NoError(t, err)

plugins/inputs/beanstalkd/beanstalkd_test.go

@@ -26,13 +26,11 @@ func TestBeanstalkd(t *testing.T) {
 		expectedError    string
 	}{
 		{
-			name:        "All tubes stats",
+			name: "All tubes stats",
-			tubesConfig: []string{},
 			expectedTubes: []tubeStats{
 				{name: "default", fields: defaultTubeFields},
 				{name: "test", fields: testTubeFields},
 			},
-			notExpectedTubes: []tubeStats{},
 		},
 		{
 			name:        "Specified tubes stats",
@@ -45,9 +43,8 @@ func TestBeanstalkd(t *testing.T) {
 			},
 		},
 		{
-			name:          "Unknown tube stats",
+			name:        "Unknown tube stats",
-			tubesConfig:   []string{"unknown"},
+			tubesConfig: []string{"unknown"},
-			expectedTubes: []tubeStats{},
 			notExpectedTubes: []tubeStats{
 				{name: "default", fields: defaultTubeFields},
 				{name: "test", fields: testTubeFields},

plugins/inputs/ceph/ceph.go

@@ -210,7 +210,7 @@ var perfDump = func(binary string, socket *socket) (string, error) {
 var findSockets = func(c *Ceph) ([]*socket, error) {
 	listing, err := os.ReadDir(c.SocketDir)
 	if err != nil {
-		return []*socket{}, fmt.Errorf("failed to read socket directory %q: %w", c.SocketDir, err)
+		return nil, fmt.Errorf("failed to read socket directory %q: %w", c.SocketDir, err)
 	}
 	sockets := make([]*socket, 0, len(listing))
 	for _, info := range listing {
@@ -714,7 +714,7 @@ type osdPoolStats []struct {
 
 // decodeOsdPoolStats decodes the output of 'ceph osd pool stats'
 func decodeOsdPoolStats(acc telegraf.Accumulator, input string) error {
-	data := osdPoolStats{}
+	data := make(osdPoolStats, 0)
 	if err := json.Unmarshal([]byte(input), &data); err != nil {
 		return fmt.Errorf("failed to parse json: %q: %w", input, err)
 	}

plugins/inputs/clickhouse/clickhouse_test.go

@@ -23,12 +23,12 @@ func TestClusterIncludeExcludeFilter(t *testing.T) {
 	ch.ClusterInclude = []string{"cluster"}
 	require.Equal(t, "WHERE cluster IN ('cluster') OR cluster NOT IN ('test_cluster')", ch.clusterIncludeExcludeFilter())
 
-	ch.ClusterExclude = []string{}
+	ch.ClusterExclude = make([]string, 0)
 	ch.ClusterInclude = []string{"cluster1", "cluster2"}
 	require.Equal(t, "WHERE cluster IN ('cluster1', 'cluster2')", ch.clusterIncludeExcludeFilter())
 
 	ch.ClusterExclude = []string{"cluster1", "cluster2"}
-	ch.ClusterInclude = []string{}
+	ch.ClusterInclude = make([]string, 0)
 	require.Equal(t, "WHERE cluster NOT IN ('cluster1', 'cluster2')", ch.clusterIncludeExcludeFilter())
 }
 
@@ -623,7 +623,7 @@ func TestWrongJSONMarshalling(t *testing.T) {
 			enc := json.NewEncoder(w)
 			// wrong data section json
 			err := enc.Encode(result{
-				Data: []struct{}{},
+				Data: make([]struct{}, 0),
 			})
 			if err != nil {
 				w.WriteHeader(http.StatusInternalServerError)

plugins/inputs/cloudwatch/cloudwatch.go

@@ -236,12 +236,12 @@ func getFilteredMetrics(c *CloudWatch) ([]filteredMetric, error) {
 		return c.metricCache.metrics, nil
 	}
 
-	fMetrics := []filteredMetric{}
+	fMetrics := make([]filteredMetric, 0)
 
 	// check for provided metric filter
 	if c.Metrics != nil {
 		for _, m := range c.Metrics {
-			metrics := []types.Metric{}
+			metrics := make([]types.Metric, 0)
 			var accounts []string
 			if !hasWildcard(m.Dimensions) {
 				dimensions := make([]types.Dimension, 0, len(m.Dimensions))
@@ -321,11 +321,11 @@ func getFilteredMetrics(c *CloudWatch) ([]filteredMetric, error) {
 
 // fetchNamespaceMetrics retrieves available metrics for a given CloudWatch namespace.
 func (c *CloudWatch) fetchNamespaceMetrics() ([]types.Metric, []string) {
-	metrics := []types.Metric{}
+	metrics := make([]types.Metric, 0)
 	var accounts []string
 	for _, namespace := range c.Namespaces {
 		params := &cloudwatch.ListMetricsInput{
-			Dimensions:            []types.DimensionFilter{},
+			Dimensions:            make([]types.DimensionFilter, 0),
 			Namespace:             aws.String(namespace),
 			IncludeLinkedAccounts: &c.IncludeLinkedAccounts,
 		}
@@ -434,7 +434,7 @@ func (c *CloudWatch) getDataQueries(filteredMetrics []filteredMetric) map[string
 func (c *CloudWatch) gatherMetrics(
 	params *cloudwatch.GetMetricDataInput,
 ) ([]types.MetricDataResult, error) {
-	results := []types.MetricDataResult{}
+	results := make([]types.MetricDataResult, 0)
 
 	for {
 		resp, err := c.client.GetMetricData(context.Background(), params)

plugins/inputs/cloudwatch/cloudwatch_test.go

@@ -312,7 +312,7 @@ func (m *mockSelectMetricsCloudWatchClient) ListMetrics(
 	_ *cloudwatch.ListMetricsInput,
 	_ ...func(*cloudwatch.Options),
 ) (*cloudwatch.ListMetricsOutput, error) {
-	metrics := []types.Metric{}
+	metrics := make([]types.Metric, 0)
 	// 4 metrics are available
 	metricNames := []string{"Latency", "RequestCount", "HealthyHostCount", "UnHealthyHostCount"}
 	// for 3 ELBs
@@ -493,7 +493,7 @@ func TestGenerateStatisticsInputParamsFiltered(t *testing.T) {
 
 func TestMetricsCacheTimeout(t *testing.T) {
 	cache := &metricCache{
-		metrics: []filteredMetric{},
+		metrics: make([]filteredMetric, 0),
 		built:   time.Now(),
 		ttl:     time.Minute,
 	}

plugins/inputs/couchbase/couchbase.go

@@ -49,7 +49,7 @@ func (*Couchbase) SampleConfig() string {
 }
 
 func (cb *Couchbase) Init() error {
-	f, err := filter.NewIncludeExcludeFilter(cb.BucketStatsIncluded, []string{})
+	f, err := filter.NewIncludeExcludeFilter(cb.BucketStatsIncluded, nil)
 	if err != nil {
 		return err
 	}

plugins/inputs/ctrlx_datalayer/ctrlx_datalayer_subscription.go

@@ -152,7 +152,7 @@ func (s *subscription) createRequest(id string) subscriptionRequest {
 
 // addressList lists all configured node addresses
 func (s *subscription) addressList() []string {
-	addressList := []string{}
+	addressList := make([]string, 0)
 	for _, node := range s.Nodes {
 		addressList = append(addressList, node.Address)
 	}

plugins/inputs/dcos/client.go

@@ -212,10 +212,8 @@ func (c *clusterClient) getSummary(ctx context.Context) (*summary, error) {
 }
 
 func (c *clusterClient) getContainers(ctx context.Context, node string) ([]container, error) {
-	list := []string{}
+	list := make([]string, 0)
-
+	err := c.doGet(ctx, c.toURL(fmt.Sprintf("/system/v1/agent/%s/metrics/v0/containers", node)), &list)
-	path := fmt.Sprintf("/system/v1/agent/%s/metrics/v0/containers", node)
-	err := c.doGet(ctx, c.toURL(path), &list)
 	if err != nil {
 		return nil, err
 	}

plugins/inputs/dcos/client_test.go

@@ -95,7 +95,7 @@ func TestGetSummary(t *testing.T) {
 			name:          "No nodes",
 			responseCode:  http.StatusOK,
 			responseBody:  `{"cluster": "a", "slaves": []}`,
-			expectedValue: &summary{Cluster: "a", Slaves: []slave{}},
+			expectedValue: &summary{Cluster: "a", Slaves: make([]slave, 0)},
 			expectedError: nil,
 		},
 		{

plugins/inputs/dcos/dcos_test.go

@@ -366,7 +366,6 @@ func TestGatherFilterNode(t *testing.T) {
 				GetSummaryF: func() (*summary, error) {
 					return &summary{
 						Cluster: "a",
-						Slaves:  []slave{},
 					}, nil
 				},
 			},
@@ -391,7 +390,7 @@ func TestGatherFilterNode(t *testing.T) {
 					}, nil
 				},
 				GetContainersF: func() ([]container, error) {
-					return []container{}, nil
+					return nil, nil
 				},
 				GetNodeMetricsF: func() (*metrics, error) {
 					return &metrics{

plugins/inputs/dmcache/dmcache_linux.go

@@ -179,7 +179,7 @@ func dmSetupStatus() ([]string, error) {
 		return nil, err
 	}
 	if string(out) == "No devices found\n" {
-		return []string{}, nil
+		return nil, nil
 	}
 
 	outString := strings.TrimRight(string(out), "\n")

plugins/inputs/dmcache/dmcache_linux_test.go

@@ -139,7 +139,7 @@ func TestNoDevicesOutput(t *testing.T) {
 	var plugin = &DMCache{
 		PerDevice: true,
 		getCurrentStatus: func() ([]string, error) {
-			return []string{}, nil
+			return nil, nil
 		},
 	}
 

plugins/inputs/docker/docker.go

@@ -128,7 +128,7 @@ func (d *Docker) Init() error {
 		if choice.Contains("cpu", d.TotalInclude) {
 			d.TotalInclude = []string{"cpu"}
 		} else {
-			d.TotalInclude = []string{}
+			d.TotalInclude = make([]string, 0)
 		}
 	}
 

plugins/inputs/docker/docker_test.go

@@ -484,8 +484,6 @@ func TestContainerLabels(t *testing.T) {
 			container: genContainerLabeled(map[string]string{
 				"a": "x",
 			}),
-			include: []string{},
-			exclude: []string{},
 			expected: map[string]string{
 				"a": "x",
 			},
@@ -497,7 +495,6 @@ func TestContainerLabels(t *testing.T) {
 				"b": "y",
 			}),
 			include: []string{"a"},
-			exclude: []string{},
 			expected: map[string]string{
 				"a": "x",
 			},
@@ -508,7 +505,6 @@ func TestContainerLabels(t *testing.T) {
 				"a": "x",
 				"b": "y",
 			}),
-			include: []string{},
 			exclude: []string{"b"},
 			expected: map[string]string{
 				"a": "x",
@@ -522,7 +518,6 @@ func TestContainerLabels(t *testing.T) {
 				"bb": "z",
 			}),
 			include: []string{"a*"},
-			exclude: []string{},
 			expected: map[string]string{
 				"aa": "x",
 				"ab": "y",
@@ -535,7 +530,6 @@ func TestContainerLabels(t *testing.T) {
 				"ab": "y",
 				"bb": "z",
 			}),
-			include: []string{},
 			exclude: []string{"a*"},
 			expected: map[string]string{
 				"bb": "z",
@@ -616,51 +610,42 @@ func TestContainerNames(t *testing.T) {
 		},
 		{
 			name:     "Empty filters matches all",
-			include:  []string{},
-			exclude:  []string{},
 			expected: []string{"etcd", "etcd2", "acme", "acme-test", "foo"},
 		},
 		{
 			name:     "Match all containers",
 			include:  []string{"*"},
-			exclude:  []string{},
 			expected: []string{"etcd", "etcd2", "acme", "acme-test", "foo"},
 		},
 		{
 			name:     "Include prefix match",
 			include:  []string{"etc*"},
-			exclude:  []string{},
 			expected: []string{"etcd", "etcd2"},
 		},
 		{
 			name:     "Exact match",
 			include:  []string{"etcd"},
-			exclude:  []string{},
 			expected: []string{"etcd"},
 		},
 		{
 			name:     "Star matches zero length",
 			include:  []string{"etcd2*"},
-			exclude:  []string{},
 			expected: []string{"etcd2"},
 		},
 		{
 			name:     "Exclude matches all",
-			include:  []string{},
 			exclude:  []string{"etc*"},
 			expected: []string{"acme", "acme-test", "foo"},
 		},
 		{
 			name:     "Exclude single",
-			include:  []string{},
 			exclude:  []string{"etcd"},
 			expected: []string{"etcd2", "acme", "acme-test", "foo"},
 		},
 		{
-			name:     "Exclude all",
+			name:    "Exclude all",
-			include:  []string{"*"},
+			include: []string{"*"},
-			exclude:  []string{"*"},
+			exclude: []string{"*"},
-			expected: []string{},
 		},
 		{
 			name:     "Exclude item matching include",
@@ -721,7 +706,7 @@ func TestContainerNames(t *testing.T) {
 }
 
 func filterMetrics(metrics []telegraf.Metric, f func(telegraf.Metric) bool) []telegraf.Metric {
-	results := []telegraf.Metric{}
+	results := make([]telegraf.Metric, 0, len(metrics))
 	for _, m := range metrics {
 		if f(m) {
 			results = append(results, m)
@@ -1406,7 +1391,6 @@ func Test_parseContainerStatsPerDeviceAndTotal(t *testing.T) {
 			args: args{
 				stat:             stats,
 				perDeviceInclude: containerMetricClasses,
-				totalInclude:     []string{},
 			},
 			expected: []telegraf.Metric{
 				metricCPU0, metricCPU1,
@@ -1417,20 +1401,16 @@ func Test_parseContainerStatsPerDeviceAndTotal(t *testing.T) {
 		{
 			name: "Total metrics enabled",
 			args: args{
-				stat:             stats,
+				stat:         stats,
-				perDeviceInclude: []string{},
+				totalInclude: containerMetricClasses,
-				totalInclude:     containerMetricClasses,
 			},
 			expected: []telegraf.Metric{metricCPUTotal, metricNetworkTotal, metricBlkioTotal},
 		},
 		{
 			name: "Per device and total metrics disabled",
 			args: args{
-				stat:             stats,
+				stat: stats,
-				perDeviceInclude: []string{},
-				totalInclude:     []string{},
 			},
-			expected: []telegraf.Metric{},
 		},
 	}
 
@@ -1468,52 +1448,46 @@ func TestDocker_Init(t *testing.T) {
 		wantTotalInclude     []string
 	}{
 		{
-			"Unsupported perdevice_include setting",
+			name: "Unsupported perdevice_include setting",
-			fields{
+			fields: fields{
 				PerDevice:        false,
 				PerDeviceInclude: []string{"nonExistentClass"},
 				Total:            false,
 				TotalInclude:     []string{"cpu"},
 			},
-			true,
+			wantErr: true,
-			[]string{},
-			[]string{},
 		},
 		{
-			"Unsupported total_include setting",
+			name: "Unsupported total_include setting",
-			fields{
+			fields: fields{
 				PerDevice:        false,
 				PerDeviceInclude: []string{"cpu"},
 				Total:            false,
 				TotalInclude:     []string{"nonExistentClass"},
 			},
-			true,
+			wantErr: true,
-			[]string{},
-			[]string{},
 		},
 		{
-			"PerDevice true adds network and blkio",
+			name: "PerDevice true adds network and blkio",
-			fields{
+			fields: fields{
 				PerDevice:        true,
 				PerDeviceInclude: []string{"cpu"},
 				Total:            true,
 				TotalInclude:     []string{"cpu"},
 			},
-			false,
+			wantPerDeviceInclude: []string{"cpu", "network", "blkio"},
-			[]string{"cpu", "network", "blkio"},
+			wantTotalInclude:     []string{"cpu"},
-			[]string{"cpu"},
 		},
 		{
-			"Total false removes network and blkio",
+			name: "Total false removes network and blkio",
-			fields{
+			fields: fields{
 				PerDevice:        false,
 				PerDeviceInclude: []string{"cpu"},
 				Total:            false,
 				TotalInclude:     []string{"cpu", "network", "blkio"},
 			},
-			false,
+			wantPerDeviceInclude: []string{"cpu"},
-			[]string{"cpu"},
+			wantTotalInclude:     []string{"cpu"},
-			[]string{"cpu"},
 		},
 	}
 	for _, tt := range tests {
@@ -1552,8 +1526,7 @@ func TestDockerGatherDiskUsage(t *testing.T) {
 
 	require.NoError(t, acc.GatherError(d.Gather))
 
-	duOpts := types.DiskUsageOptions{Types: []types.DiskUsageObject{}}
+	d.gatherDiskUsage(&acc, types.DiskUsageOptions{})
-	d.gatherDiskUsage(&acc, duOpts)
 
 	acc.AssertContainsTaggedFields(t,
 		"docker_disk_usage",

plugins/inputs/docker/docker_testdata.go

@@ -40,15 +40,15 @@ var info = system.Info{
 		IndexConfigs: map[string]*registry.IndexInfo{
 			"docker.io": {
 				Name:     "docker.io",
-				Mirrors:  []string{},
+				Mirrors:  make([]string, 0),
 				Official: true,
 				Secure:   true,
 			},
-		}, InsecureRegistryCIDRs: []*registry.NetIPNet{{IP: []byte{127, 0, 0, 0}, Mask: []byte{255, 0, 0, 0}}}, Mirrors: []string{}},
+		}, InsecureRegistryCIDRs: []*registry.NetIPNet{{IP: []byte{127, 0, 0, 0}, Mask: []byte{255, 0, 0, 0}}}, Mirrors: make([]string, 0)},
 	OperatingSystem:  "Linux Mint LMDE (containerized)",
 	BridgeNfIptables: true,
 	HTTPSProxy:       "",
-	Labels:           []string{},
+	Labels:           make([]string, 0),
 	MemoryLimit:      false,
 	DriverStatus: [][2]string{
 		{"Pool Name", "docker-8:1-1182287-pool"},

plugins/inputs/dpdk/dpdk_test.go

@@ -86,10 +86,9 @@ func Test_Init(t *testing.T) {
 	t.Run("when device_types and additional_commands are empty, then error should be returned", func(t *testing.T) {
 		pathToSocket, _ := createSocketForTest(t, "")
 		dpdk := Dpdk{
-			SocketPath:         pathToSocket,
+			SocketPath:  pathToSocket,
-			DeviceTypes:        []string{},
+			DeviceTypes: make([]string, 0),
-			AdditionalCommands: []string{},
+			Log:         testutil.Logger{},
-			Log:                testutil.Logger{},
 		}
 
 		err := dpdk.Init()
@@ -481,10 +480,6 @@ func Test_getCommandsAndParamsCombinations(t *testing.T) {
 
 		dpdk.DeviceTypes = []string{"ethdev"}
 		dpdk.ethdevCommands = []string{"/ethdev/stats", "/ethdev/xstats"}
-		var err error
-		dpdk.ethdevExcludedCommandsFilter, err = filter.Compile([]string{})
-		require.NoError(t, err)
-		dpdk.AdditionalCommands = []string{}
 		commands := dpdk.gatherCommands(mockAcc, dpdk.connectors[0])
 
 		require.ElementsMatch(t, commands, expectedCommands)
@@ -500,7 +495,6 @@ func Test_getCommandsAndParamsCombinations(t *testing.T) {
 
 		dpdk.DeviceTypes = []string{"rawdev"}
 		dpdk.rawdevCommands = []string{"/rawdev/xstats"}
-		dpdk.AdditionalCommands = []string{}
 		commands := dpdk.gatherCommands(mockAcc, dpdk.connectors[0])
 
 		require.ElementsMatch(t, commands, expectedCommands)
@@ -519,7 +513,6 @@ func Test_getCommandsAndParamsCombinations(t *testing.T) {
 		var err error
 		dpdk.ethdevExcludedCommandsFilter, err = filter.Compile([]string{"/ethdev/xstats"})
 		require.NoError(t, err)
-		dpdk.AdditionalCommands = []string{}
 		commands := dpdk.gatherCommands(mockAcc, dpdk.connectors[0])
 
 		require.ElementsMatch(t, commands, expectedCommands)
@@ -533,10 +526,6 @@ func Test_getCommandsAndParamsCombinations(t *testing.T) {
 
 		dpdk.DeviceTypes = []string{"ethdev"}
 		dpdk.ethdevCommands = []string{"/ethdev/stats", "/ethdev/xstats"}
-		var err error
-		dpdk.ethdevExcludedCommandsFilter, err = filter.Compile([]string{})
-		require.NoError(t, err)
-		dpdk.AdditionalCommands = []string{}
 		commands := dpdk.gatherCommands(mockAcc, dpdk.connectors[0])
 
 		require.Empty(t, commands)
@@ -607,7 +596,7 @@ func Test_Gather(t *testing.T) {
 		mockAcc := &testutil.Accumulator{}
 		dpdk := Dpdk{
 			Log:           testutil.Logger{},
-			PluginOptions: []string{},
+			PluginOptions: make([]string, 0),
 		}
 
 		require.NoError(t, dpdk.Init())
@@ -621,7 +610,6 @@ func Test_Gather(t *testing.T) {
 		mockAcc := &testutil.Accumulator{}
 		dpdk := Dpdk{
 			Log:                       testutil.Logger{},
-			PluginOptions:             []string{},
 			UnreachableSocketBehavior: unreachableSocketBehaviorIgnore,
 		}
 		require.NoError(t, dpdk.Init())
@@ -769,7 +757,6 @@ func Test_Gather(t *testing.T) {
 			MaxOutputLen: 1024,
 		}
 		mockConn, dpdk, mockAcc := prepareEnvironmentWithInitializedMessage(testInitMessage)
-		dpdk.MetadataFields = []string{}
 		defer mockConn.AssertExpectations(t)
 		dpdk.AdditionalCommands = []string{"/endpoint1"}
 		simulateResponse(mockConn, `{"/endpoint1":"myvalue"}`, nil)
@@ -801,7 +788,6 @@ func Test_Gather(t *testing.T) {
 func Test_Gather_MultiSocket(t *testing.T) {
 	t.Run("Test Gather without Metadata Fields", func(t *testing.T) {
 		mockConns, dpdk, mockAcc := prepareEnvironmentWithMultiSockets()
-		dpdk.MetadataFields = []string{}
 		defer func() {
 			for _, mockConn := range mockConns {
 				mockConn.AssertExpectations(t)