Add ExcludeInterfaceRegexp to Net Dev monitor

pkg/systemstatsmonitor/README.md

@@ -118,6 +118,8 @@ Below metrics are collected from `net` component:
 
 All of the above have `interface_name` label for the net interface.
 
+Interfaces can be skipped if they don't add any value. See field `ExcludeInterfaceRegexp`.
+
 ## Windows Support
 
 NPD has preliminary support for system stats monitor. The following modules are supported:

pkg/systemstatsmonitor/net_collector.go

@@ -26,19 +26,20 @@ import (
 	"github.com/prometheus/procfs"
 )
 
+type newInt64MetricFn func(metricID metrics.MetricID, viewName string, description string, unit string, aggregation metrics.Aggregation, tagNames []string) (metrics.Int64MetricInterface, error)
+
+// newInt64Metric is a wrapper of metrics.NewInt64Metric that returns an interface instead of the specific type
+func newInt64Metric(metricID metrics.MetricID, viewName string, description string, unit string, aggregation metrics.Aggregation, tagNames []string) (metrics.Int64MetricInterface, error) {
+	return metrics.NewInt64Metric(metricID, viewName, description, unit, aggregation, tagNames)
+}
+
 type netCollector struct {
 	config   *ssmtypes.NetStatsConfig
 	procPath string
 	recorder *ifaceStatRecorder
 }
 
-func NewNetCollectorOrDie(netConfig *ssmtypes.NetStatsConfig, procPath string) *netCollector {
-	nc := netCollector{
-		config:   netConfig,
-		procPath: procPath,
-		recorder: newIfaceStatRecorder(),
-	}
-
+func (nc *netCollector) initOrDie() {
 	nc.mustRegisterMetric(
 		metrics.NetDevRxBytes,
 		"Cumulative count of bytes received.",
@@ -191,8 +192,16 @@ func NewNetCollectorOrDie(netConfig *ssmtypes.NetStatsConfig, procPath string) *
 			return int64(stat.TxCompressed)
 		},
 	)
+}
 
-	return &nc
+func NewNetCollectorOrDie(netConfig *ssmtypes.NetStatsConfig, procPath string) *netCollector {
+	nc := &netCollector{
+		config:   netConfig,
+		procPath: procPath,
+		recorder: newIfaceStatRecorder(newInt64Metric),
+	}
+	nc.initOrDie()
+	return nc
 }
 
 func (nc *netCollector) mustRegisterMetric(metricID metrics.MetricID, description, unit string,
@@ -216,7 +225,11 @@ func (nc *netCollector) recordNetDev() {
 		return
 	}
 
+	excludeInterfaceRegexp := nc.config.ExcludeInterfaceRegexp.R
 	for iface, ifaceStats := range stats {
+		if excludeInterfaceRegexp != nil && excludeInterfaceRegexp.MatchString(iface) {
+			continue
+		}
 		tags := map[string]string{}
 		tags[interfaceNameLabel] = iface
 
@@ -234,11 +247,16 @@ func (nc *netCollector) collect() {
 
 // TODO(@oif): Maybe implements a generic recorder
 type ifaceStatRecorder struct {
-	collectors map[metrics.MetricID]ifaceStatCollector
+	// We use a function to allow injecting a mock for testing
+	newInt64Metric newInt64MetricFn
+	collectors     map[metrics.MetricID]ifaceStatCollector
 }
 
-func newIfaceStatRecorder() *ifaceStatRecorder {
-	return &ifaceStatRecorder{collectors: make(map[metrics.MetricID]ifaceStatCollector)}
+func newIfaceStatRecorder(newInt64Metric newInt64MetricFn) *ifaceStatRecorder {
+	return &ifaceStatRecorder{
+		newInt64Metric: newInt64Metric,
+		collectors:     make(map[metrics.MetricID]ifaceStatCollector),
+	}
 }
 
 func (r *ifaceStatRecorder) Register(metricID metrics.MetricID, viewName string, description string,
@@ -247,7 +265,7 @@ func (r *ifaceStatRecorder) Register(metricID metrics.MetricID, viewName string,
 		// Check duplication
 		return fmt.Errorf("metric %q already registered", metricID)
 	}
-	metric, err := metrics.NewInt64Metric(metricID, viewName, description, unit, aggregation, tagNames)
+	metric, err := r.newInt64Metric(metricID, viewName, description, unit, aggregation, tagNames)
 	if err != nil {
 		return err
 	}
@@ -268,6 +286,6 @@ func (r ifaceStatRecorder) RecordWithSameTags(stat procfs.NetDevLine, tags map[s
 }
 
 type ifaceStatCollector struct {
-	metric   *metrics.Int64Metric
+	metric   metrics.Int64MetricInterface
 	exporter func(procfs.NetDevLine) int64
 }

pkg/systemstatsmonitor/net_collector_test.go

@@ -0,0 +1,189 @@
+package systemstatsmonitor
+
+import (
+	"io/ioutil"
+	"os"
+	"path"
+	"regexp"
+	"testing"
+
+	ssmtypes "k8s.io/node-problem-detector/pkg/systemstatsmonitor/types"
+	"k8s.io/node-problem-detector/pkg/util/metrics"
+)
+
+var defaultMetricsConfig = map[string]ssmtypes.MetricConfig{
+	string(metrics.NetDevRxBytes):      ssmtypes.MetricConfig{DisplayName: string(metrics.NetDevRxBytes)},
+	string(metrics.NetDevRxPackets):    ssmtypes.MetricConfig{DisplayName: string(metrics.NetDevRxPackets)},
+	string(metrics.NetDevRxErrors):     ssmtypes.MetricConfig{DisplayName: string(metrics.NetDevRxErrors)},
+	string(metrics.NetDevRxDropped):    ssmtypes.MetricConfig{DisplayName: string(metrics.NetDevRxDropped)},
+	string(metrics.NetDevRxFifo):       ssmtypes.MetricConfig{DisplayName: string(metrics.NetDevRxFifo)},
+	string(metrics.NetDevRxFrame):      ssmtypes.MetricConfig{DisplayName: string(metrics.NetDevRxFrame)},
+	string(metrics.NetDevRxCompressed): ssmtypes.MetricConfig{DisplayName: string(metrics.NetDevRxCompressed)},
+	string(metrics.NetDevRxMulticast):  ssmtypes.MetricConfig{DisplayName: string(metrics.NetDevRxMulticast)},
+	string(metrics.NetDevTxBytes):      ssmtypes.MetricConfig{DisplayName: string(metrics.NetDevTxBytes)},
+	string(metrics.NetDevTxPackets):    ssmtypes.MetricConfig{DisplayName: string(metrics.NetDevTxPackets)},
+	string(metrics.NetDevTxErrors):     ssmtypes.MetricConfig{DisplayName: string(metrics.NetDevTxErrors)},
+	string(metrics.NetDevTxDropped):    ssmtypes.MetricConfig{DisplayName: string(metrics.NetDevTxDropped)},
+	string(metrics.NetDevTxFifo):       ssmtypes.MetricConfig{DisplayName: string(metrics.NetDevTxFifo)},
+	string(metrics.NetDevTxCollisions): ssmtypes.MetricConfig{DisplayName: string(metrics.NetDevTxCollisions)},
+	string(metrics.NetDevTxCarrier):    ssmtypes.MetricConfig{DisplayName: string(metrics.NetDevTxCarrier)},
+	string(metrics.NetDevTxCompressed): ssmtypes.MetricConfig{DisplayName: string(metrics.NetDevTxCompressed)},
+}
+
+// docker:	1500	100		8		7		0		0		0		0		9000	450		565		200		20		30		0		0
+const fakeNetProcContent = `Inter-|   Receive                                                |  Transmit
+face |bytes    packets errs drop fifo frame compressed multicast|bytes    packets errs drop fifo colls carrier compressed
+eth0:		5000	100		0		0		0 		0 		0 		0		2500	30		0		0		0		0		0		0  
+docker0: 	1000	90		8		7		0 		0 		0 		0		0		0		0		0		0		0		0		0
+docker1: 	500		10		0		0		0 		0		0		0		3000	150		15		0		20		30		0		0
+docker2:	0		0		0		0		0		0		0		0		6000	300		550		200		0		0		0		0
+`
+
+// newFakeInt64Metric is a wrapper around metrics.NewFakeInt64Metric
+func newFakeInt64Metric(metricID metrics.MetricID, viewName string, description string, unit string, aggregation metrics.Aggregation, tagNames []string) (metrics.Int64MetricInterface, error) {
+	return metrics.NewFakeInt64Metric(viewName, aggregation, tagNames), nil
+}
+
+// testCollectAux is a test auxiliary function used for testing netCollector.Collect
+func testCollectAux(t *testing.T, name string, excludeInterfaceRegexp ssmtypes.NetStatsInterfaceRegexp, validate func(*testing.T, *netCollector)) {
+	// mkdir /tmp/proc-X
+	procDir, err := ioutil.TempDir(os.TempDir(), "proc-")
+	if err != nil {
+		t.Fatalf("Failed to create temp proc directory: %v", err)
+	}
+	// rm -r /tmp/proc-X
+	defer os.RemoveAll(procDir)
+	// mkdir -C /tmp/proc-X/net
+	procNetDir := path.Join(procDir, "net")
+	if err := os.Mkdir(procNetDir, 0777); err != nil {
+		t.Fatalf("Failed to create directory %q: %v", procNetDir, err)
+	}
+
+	// touch /tmp/proc-X/net/dev
+	filename := path.Join(procNetDir, "dev")
+	f, err := os.Create(filename)
+	if err != nil {
+		t.Fatalf("Failed to create file %q: %v", filename, err)
+	}
+	// echo $FILE_CONTENT > /tmp/proc-X/net/dev
+	if _, err = f.WriteString(fakeNetProcContent); err != nil {
+		t.Fatalf("Failed to write to file %q: %v", filename, err)
+	}
+	if err = f.Close(); err != nil {
+		t.Fatalf("Failed to close file %q: %v", filename, err)
+	}
+
+	// Build the netCollector
+	config := &ssmtypes.NetStatsConfig{
+		ExcludeInterfaceRegexp: excludeInterfaceRegexp,
+		MetricsConfigs:         defaultMetricsConfig,
+	}
+	netCollector := &netCollector{
+		config:   config,
+		procPath: procDir,
+		recorder: newIfaceStatRecorder(newFakeInt64Metric),
+	}
+	netCollector.initOrDie()
+	netCollector.collect()
+	validate(t, netCollector)
+}
+
+func TestCollect(t *testing.T) {
+	tcs := []struct {
+		Name                   string
+		ExcludeInterfaceRegexp ssmtypes.NetStatsInterfaceRegexp
+		Validate               func(t *testing.T, nc *netCollector)
+	}{
+		{
+			Name:                   "NoFilterMatch",
+			ExcludeInterfaceRegexp: ssmtypes.NetStatsInterfaceRegexp{R: regexp.MustCompile(`^fake$`)},
+			Validate: func(t *testing.T, nc *netCollector) {
+				// We just validate two metrics, no need to check all of them
+				expectedValues := map[metrics.MetricID]map[string]int64{
+					metrics.NetDevRxBytes: map[string]int64{
+						"eth0":    5000,
+						"docker0": 1000,
+						"docker1": 500,
+						"docker2": 0,
+					},
+					metrics.NetDevTxBytes: map[string]int64{
+						"eth0":    2500,
+						"docker0": 0,
+						"docker1": 3000,
+						"docker2": 6000,
+					},
+				}
+				for metricID, interfaceValues := range expectedValues {
+					collector, ok := nc.recorder.collectors[metricID]
+					if !ok {
+						t.Errorf("Failed to get collector of metric %s", metricID)
+						continue
+					}
+					fakeInt64Metric, ok := collector.metric.(*metrics.FakeInt64Metric)
+					if !ok {
+						t.Fatalf("Failed to convert metric %s to fakeMetric", string(metricID))
+					}
+					for _, repr := range fakeInt64Metric.ListMetrics() {
+						interfaceName, ok := repr.Labels[interfaceNameLabel]
+						if !ok {
+							t.Fatalf("Failed to get label %q for ", interfaceNameLabel)
+						}
+						expectedValue, ok := interfaceValues[interfaceName]
+						if !ok {
+
+						}
+						if repr.Value != expectedValue {
+							t.Errorf("Mismatch in metric %q for interface %q: expected %d, got %d", metricID, interfaceName, expectedValue, repr.Value)
+						}
+					}
+				}
+			},
+		},
+		{
+			Name:                   "FilterMatch",
+			ExcludeInterfaceRegexp: ssmtypes.NetStatsInterfaceRegexp{R: regexp.MustCompile(`docker\d+`)},
+			Validate: func(t *testing.T, nc *netCollector) {
+				// We just validate two metrics, no need to check all of them
+				expectedValues := map[metrics.MetricID]map[string]int64{
+					metrics.NetDevRxBytes: map[string]int64{
+						"eth0": 5000,
+					},
+					metrics.NetDevTxBytes: map[string]int64{
+						"eth0": 2500,
+					},
+				}
+				for metricID, interfaceValues := range expectedValues {
+					collector, ok := nc.recorder.collectors[metricID]
+					if !ok {
+						t.Errorf("Failed to get collector of metric %s", metricID)
+						continue
+					}
+					fakeInt64Metric, ok := collector.metric.(*metrics.FakeInt64Metric)
+					if !ok {
+						t.Fatalf("Failed to convert metric %s to fakeMetric", string(metricID))
+					}
+					for _, repr := range fakeInt64Metric.ListMetrics() {
+						interfaceName, ok := repr.Labels[interfaceNameLabel]
+						if !ok {
+							t.Fatalf("Failed to get label %q for ", interfaceNameLabel)
+						}
+						expectedValue, ok := interfaceValues[interfaceName]
+						if !ok {
+
+						}
+						if repr.Value != expectedValue {
+							t.Errorf("Mismatch in metric %q for interface %q: expected %d, got %d", metricID, interfaceName, expectedValue, repr.Value)
+						}
+					}
+				}
+			},
+		},
+	}
+	for _, tc := range tcs {
+		tc := tc
+		t.Run(tc.Name, func(t *testing.T) {
+			t.Parallel()
+			testCollectAux(t, tc.Name, tc.ExcludeInterfaceRegexp, tc.Validate)
+		})
+	}
+}

pkg/systemstatsmonitor/types/config.go

@@ -19,6 +19,7 @@ package types
 import (
 	"fmt"
 	"os"
+	"regexp"
 	"time"
 )
 
@@ -58,8 +59,35 @@ type OSFeatureStatsConfig struct {
 	KnownModulesConfigPath string                  `json:"knownModulesConfigPath"`
 }
 
+// In order to marshal/unmarshal regexp, we need to implement Marshal/Unmarshal
+// methods in a wrapper struct
+type NetStatsInterfaceRegexp struct {
+	R *regexp.Regexp
+}
+
+func (r *NetStatsInterfaceRegexp) Unmarshal(data []byte) error {
+	// We don't build Regexp if data is empty
+	if len(data) == 0 {
+		return nil
+	}
+	regex, err := regexp.Compile(string(data))
+	if err != nil {
+		return err
+	}
+	r.R = regex
+	return nil
+}
+
+func (r NetStatsInterfaceRegexp) Marshal() ([]byte, error) {
+	if r.R == nil {
+		return nil, nil
+	}
+	return []byte(r.R.String()), nil
+}
+
 type NetStatsConfig struct {
-	MetricsConfigs map[string]MetricConfig `json:"metricsConfigs"`
+	MetricsConfigs         map[string]MetricConfig `json:"metricsConfigs"`
+	ExcludeInterfaceRegexp NetStatsInterfaceRegexp `json:"excludeInterfaceRegexp"`
 }
 
 type SystemStatsConfig struct {