Implement indices filters

collector/collector.go

@@ -18,6 +18,7 @@ import (
 	"encoding/binary"
 	"fmt"
 	"net"
+	"regexp"
 	"strconv"
 	"strings"
 	"time"
@@ -170,7 +171,39 @@ func ScrapeTarget(ctx context.Context, target string, config *config.Module, log
 	}
 	defer snmp.Conn.Close()
 
-	getOids := config.Get
+	// Evaluate rules.
+	newGet := config.Get
+	newWalk := config.Walk
+	for _, filter := range config.Filters {
+		var pdus []gosnmp.SnmpPDU
+		allowedList := []string{}
+
+		if snmp.Version == gosnmp.Version1 {
+			pdus, err = snmp.WalkAll(filter.Oid)
+		} else {
+			pdus, err = snmp.BulkWalkAll(filter.Oid)
+		}
+		// Do not try to filter anything if we had errors.
+		if err != nil {
+			level.Info(logger).Log("msg", "Error getting OID, won't do any filter on this oid", "oid", filter.Oid)
+			continue
+		}
+
+		allowedList = filterAllowedIndices(logger, filter, pdus, allowedList)
+
+		// Update config to get only index and not walk them.
+		newWalk = updateWalkConfig(newWalk, filter, logger)
+
+		// Only Keep indices not involved in filters.
+		newCfg := updateGetConfig(newGet, filter, logger)
+
+		// We now add each index from filter to the get list.
+		newCfg = addAllowedIndices(filter, allowedList, logger, newCfg)
+
+		newGet = newCfg
+	}
+
+	getOids := newGet
 	maxOids := int(config.WalkParams.MaxRepetitions)
 	// Max Repetition can be 0, maxOids cannot. SNMPv1 can only report one OID error per call.
 	if maxOids == 0 || snmp.Version == gosnmp.Version1 {
@@ -213,7 +246,7 @@ func ScrapeTarget(ctx context.Context, target string, config *config.Module, log
 		getOids = getOids[oids:]
 	}
 
-	for _, subtree := range config.Walk {
+	for _, subtree := range newWalk {
 		var pdus []gosnmp.SnmpPDU
 		level.Debug(logger).Log("msg", "Walking subtree", "oid", subtree)
 		walkStart := time.Now()
@@ -235,6 +268,77 @@ func ScrapeTarget(ctx context.Context, target string, config *config.Module, log
 	return results, nil
 }
 
+func filterAllowedIndices(logger log.Logger, filter config.DynamicFilter, pdus []gosnmp.SnmpPDU, allowedList []string) []string {
+	level.Debug(logger).Log("msg", "Evaluating rule for oid", "oid", filter.Oid)
+	for _, pdu := range pdus {
+		found := false
+		for _, val := range filter.Values {
+			snmpval := pduValueAsString(&pdu, "DisplayString")
+			level.Debug(logger).Log("config value", val, "snmp value", snmpval)
+
+			if regexp.MustCompile(val).MatchString(snmpval) {
+				found = true
+				break
+			}
+		}
+		if found {
+			pduArray := strings.Split(pdu.Name, ".")
+			index := pduArray[len(pduArray)-1]
+			level.Debug(logger).Log("msg", "Caching index", "index", index)
+			allowedList = append(allowedList, index)
+		}
+	}
+	return allowedList
+}
+
+func updateWalkConfig(walkConfig []string, filter config.DynamicFilter, logger log.Logger) []string {
+	newCfg := []string{}
+	for _, elem := range walkConfig {
+		found := false
+		for _, targetOid := range filter.Targets {
+			if elem == targetOid {
+				level.Debug(logger).Log("msg", "Deleting for walk configuration", "oid", targetOid)
+				found = true
+				break
+			}
+		}
+		// Oid not found in target,  we walk it.
+		if !found {
+			newCfg = append(newCfg, elem)
+		}
+	}
+	return newCfg
+}
+
+func updateGetConfig(getConfig []string, filter config.DynamicFilter, logger log.Logger) []string {
+	newCfg := []string{}
+	for _, elem := range getConfig {
+		found := false
+		for _, targetOid := range filter.Targets {
+			if strings.HasPrefix(elem, targetOid) {
+				found = true
+				break
+			}
+		}
+		// Oid not found in targets, we keep it.
+		if !found {
+			level.Debug(logger).Log("msg", "Keeping get configuration", "oid", elem)
+			newCfg = append(newCfg, elem)
+		}
+	}
+	return newCfg
+}
+
+func addAllowedIndices(filter config.DynamicFilter, allowedList []string, logger log.Logger, newCfg []string) []string {
+	for _, targetOid := range filter.Targets {
+		for _, index := range allowedList {
+			level.Debug(logger).Log("msg", "Adding get configuration", "oid", targetOid+"."+index)
+			newCfg = append(newCfg, targetOid+"."+index)
+		}
+	}
+	return newCfg
+}
+
 type MetricNode struct {
 	metric *config.Metric
 

collector/collector_test.go

@@ -1008,3 +1008,148 @@ func TestIndexesToLabels(t *testing.T) {
 		}
 	}
 }
+
+func TestFilterAllowedIndices(t *testing.T) {
+
+	pdus := []gosnmp.SnmpPDU{
+		gosnmp.SnmpPDU{
+			Name:  "1.3.6.1.2.1.2.2.1.8.1",
+			Value: "2",
+		},
+		gosnmp.SnmpPDU{
+			Name:  "1.3.6.1.2.1.2.2.1.8.2",
+			Value: "1",
+		},
+		gosnmp.SnmpPDU{
+			Name:  "1.3.6.1.2.1.2.2.1.8.3",
+			Value: "1",
+		},
+		gosnmp.SnmpPDU{
+			Name:  "1.3.6.1.2.1.2.2.1.8.4",
+			Value: "5",
+		},
+	}
+
+	cases := []struct {
+		filter      config.DynamicFilter
+		allowedList []string
+		result      []string
+	}{
+		{
+			filter: config.DynamicFilter{
+				Oid:     "1.3.6.1.2.1.2.2.1.8",
+				Targets: []string{"1.3.6.1.2.1.2.2.1.3", "1.3.6.1.2.1.2.2.1.5"},
+				Values:  []string{"1"},
+			},
+			result: []string{"2", "3"},
+		},
+		{
+			filter: config.DynamicFilter{
+				Oid:     "1.3.6.1.2.1.2.2.1.8",
+				Targets: []string{"1.3.6.1.2.1.2.2.1.3", "1.3.6.1.2.1.2.2.1.5"},
+				Values:  []string{"5"},
+			},
+			result: []string{"4"},
+		},
+	}
+	for _, c := range cases {
+		got := filterAllowedIndices(log.NewNopLogger(), c.filter, pdus, c.allowedList)
+		if !reflect.DeepEqual(got, c.result) {
+			t.Errorf("filterAllowedIndices(%v): got %v, want %v", c.filter, got, c.result)
+		}
+	}
+}
+
+func TestUpdateWalkConfig(t *testing.T) {
+	cases := []struct {
+		filter config.DynamicFilter
+		result []string
+	}{
+		{
+			filter: config.DynamicFilter{
+				Oid:     "1.3.6.1.2.1.2.2.1.8",
+				Targets: []string{"1.3.6.1.2.1.2.2.1.3", "1.3.6.1.2.1.2.2.1.5", "1.3.6.1.2.1.2.2.1.7"},
+				Values:  []string{"1"},
+			},
+			result: []string{},
+		},
+		{
+			filter: config.DynamicFilter{
+				Oid:     "1.3.6.1.2.1.2.2.1.8",
+				Targets: []string{"1.3.6.1.2.1.2.2.1.3", "1.3.6.1.2.1.2.2.1.21"},
+				Values:  []string{"1"},
+			},
+			result: []string{"1.3.6.1.2.1.2.2.1.5", "1.3.6.1.2.1.2.2.1.7"},
+		},
+	}
+	walkConfig := []string{"1.3.6.1.2.1.2.2.1.3", "1.3.6.1.2.1.2.2.1.5", "1.3.6.1.2.1.2.2.1.7"}
+	for _, c := range cases {
+		got := updateWalkConfig(walkConfig, c.filter, log.NewNopLogger())
+		if !reflect.DeepEqual(got, c.result) {
+			t.Errorf("updateWalkConfig(%v): got %v, want %v", c.filter, got, c.result)
+		}
+	}
+}
+
+func TestUpdateGetConfig(t *testing.T) {
+	cases := []struct {
+		filter config.DynamicFilter
+		result []string
+	}{
+		{
+			filter: config.DynamicFilter{
+				Oid:     "1.3.6.1.2.1.2.2.1.8",
+				Targets: []string{"1.3.6.1.2.1.2.2.1"},
+				Values:  []string{"1"},
+			},
+			result: []string{},
+		},
+		{
+			filter: config.DynamicFilter{
+				Oid:     "1.3.6.1.2.1.2.2.1.8",
+				Targets: []string{"1.3.6.1.2.1.2.2.1.3", "1.3.6.1.2.1.2.2.1.21"},
+				Values:  []string{"1"},
+			},
+			result: []string{"1.3.6.1.2.1.2.2.1.5", "1.3.6.1.2.1.2.2.1.7"},
+		},
+	}
+	getConfig := []string{"1.3.6.1.2.1.2.2.1.3", "1.3.6.1.2.1.2.2.1.5", "1.3.6.1.2.1.2.2.1.7"}
+	for _, c := range cases {
+		got := updateGetConfig(getConfig, c.filter, log.NewNopLogger())
+		if !reflect.DeepEqual(got, c.result) {
+			t.Errorf("updateGetConfig(%v): got %v, want %v", c.filter, got, c.result)
+		}
+	}
+}
+
+func TestAddAllowedIndices(t *testing.T) {
+	cases := []struct {
+		filter config.DynamicFilter
+		result []string
+	}{
+		{
+			filter: config.DynamicFilter{
+				Oid:     "1.3.6.1.2.1.2.2.1.8",
+				Targets: []string{"1.3.6.1.2.1.2.2.1"},
+				Values:  []string{"1"},
+			},
+			result: []string{"1.3.6.1.2.1.31.1.1.1.10", "1.3.6.1.2.1.31.1.1.1.11", "1.3.6.1.2.1.2.2.1.2", "1.3.6.1.2.1.2.2.1.3"},
+		},
+		{
+			filter: config.DynamicFilter{
+				Oid:     "1.3.6.1.2.1.2.2.1.8",
+				Targets: []string{"1.3.6.1.2.1.2.2.1.3", "1.3.6.1.2.1.2.2.1.21"},
+				Values:  []string{"1"},
+			},
+			result: []string{"1.3.6.1.2.1.31.1.1.1.10", "1.3.6.1.2.1.31.1.1.1.11", "1.3.6.1.2.1.2.2.1.3.2", "1.3.6.1.2.1.2.2.1.3.3", "1.3.6.1.2.1.2.2.1.21.2", "1.3.6.1.2.1.2.2.1.21.3"},
+		},
+	}
+	allowedList := []string{"2", "3"}
+	newCfg := []string{"1.3.6.1.2.1.31.1.1.1.10", "1.3.6.1.2.1.31.1.1.1.11"}
+	for _, c := range cases {
+		got := addAllowedIndices(c.filter, allowedList, log.NewNopLogger(), newCfg)
+		if !reflect.DeepEqual(got, c.result) {
+			t.Errorf("addAllowedIndices(%v): got %v, want %v", c.filter, got, c.result)
+		}
+	}
+}

config/config.go

@@ -77,10 +77,11 @@ type WalkParams struct {
 
 type Module struct {
 	// A list of OIDs.
-	Walk       []string   `yaml:"walk,omitempty"`
-	Get        []string   `yaml:"get,omitempty"`
-	Metrics    []*Metric  `yaml:"metrics"`
-	WalkParams WalkParams `yaml:",inline"`
+	Walk       []string        `yaml:"walk,omitempty"`
+	Get        []string        `yaml:"get,omitempty"`
+	Metrics    []*Metric       `yaml:"metrics"`
+	WalkParams WalkParams      `yaml:",inline"`
+	Filters    []DynamicFilter `yaml:"filters,omitempty"`
 }
 
 func (c *Module) UnmarshalYAML(unmarshal func(interface{}) error) error {
@@ -191,6 +192,21 @@ func (c WalkParams) ConfigureSNMP(g *gosnmp.GoSNMP) {
 	g.SecurityParameters = usm
 }
 
+type Filters struct {
+	Static  []StaticFilter  `yaml:"static,omitempty"`
+	Dynamic []DynamicFilter `yaml:"dynamic,omitempty"`
+}
+
+type StaticFilter struct {
+	Targets []string `yaml:"targets,omitempty"`
+	Indices []string `yaml:"indices,omitempty"`
+}
+type DynamicFilter struct {
+	Oid     string   `yaml:"oid"`
+	Targets []string `yaml:"targets,omitempty"`
+	Values  []string `yaml:"values,omitempty"`
+}
+
 type Metric struct {
 	Name           string                     `yaml:"name"`
 	Oid            string                     `yaml:"oid"`

generator/Dockerfile-local

@@ -0,0 +1,14 @@
+FROM golang:latest
+
+RUN apt-get update && \
+    apt-get install -y libsnmp-dev p7zip-full
+
+COPY ./generator  /bin/generator
+
+WORKDIR "/opt"
+
+ENTRYPOINT ["/bin/generator"]
+
+ENV MIBDIRS mibs
+
+CMD ["generate"]