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Allow custom registry for initialization of collector metrics (#885)
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* Explicit registration of collector metrics

---------

Signed-off-by: Marc Tuduri <[email protected]>
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@marctc
marctc authored Jun 23, 2023
1 parent 9644498 commit 4a3227b
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Showing 3 changed files with 78 additions and 60 deletions.
126 changes: 72 additions & 54 deletions collector/collector.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -38,36 +38,6 @@ const (
)

var (
buckets = prometheus.ExponentialBuckets(0.0001, 2, 15)
snmpUnexpectedPduType = promauto.NewCounter(
prometheus.CounterOpts{
Namespace: namespace,
Name: "unexpected_pdu_type_total",
Help: "Unexpected Go types in a PDU.",
},
)
snmpDuration = promauto.NewHistogram(
prometheus.HistogramOpts{
Namespace: namespace,
Name: "packet_duration_seconds",
Help: "A histogram of latencies for SNMP packets.",
Buckets: buckets,
},
)
snmpPackets = promauto.NewCounter(
prometheus.CounterOpts{
Namespace: namespace,
Name: "packets_total",
Help: "Number of SNMP packet sent, including retries.",
},
)
snmpRetries = promauto.NewCounter(
prometheus.CounterOpts{
Namespace: namespace,
Name: "packet_retries_total",
Help: "Number of SNMP packet retries.",
},
)
// 64-bit float mantissa: https://en.wikipedia.org/wiki/Double-precision_floating-point_format
float64Mantissa uint64 = 9007199254740992
wrapCounters = kingpin.Flag("snmp.wrap-large-counters", "Wrap 64-bit counters to avoid floating point rounding.").Default("true").Bool()
Expand Down Expand Up @@ -116,7 +86,7 @@ type ScrapeResults struct {
retries uint64
}

func ScrapeTarget(ctx context.Context, target string, auth *config.Auth, module *config.Module, logger log.Logger) (ScrapeResults, error) {
func ScrapeTarget(ctx context.Context, target string, auth *config.Auth, module *config.Module, logger log.Logger, metrics internalMetrics) (ScrapeResults, error) {
results := ScrapeResults{}
// Set the options.
snmp := gosnmp.GoSNMP{}
Expand All @@ -136,14 +106,14 @@ func ScrapeTarget(ctx context.Context, target string, auth *config.Auth, module
var sent time.Time
snmp.OnSent = func(x *gosnmp.GoSNMP) {
sent = time.Now()
snmpPackets.Inc()
metrics.snmpPackets.Inc()
results.packets++
}
snmp.OnRecv = func(x *gosnmp.GoSNMP) {
snmpDuration.Observe(time.Since(sent).Seconds())
metrics.snmpDuration.Observe(time.Since(sent).Seconds())
}
snmp.OnRetry = func(x *gosnmp.GoSNMP) {
snmpRetries.Inc()
metrics.snmpRetries.Inc()
results.retries++
}

Expand Down Expand Up @@ -191,7 +161,7 @@ func ScrapeTarget(ctx context.Context, target string, auth *config.Auth, module
continue
}

allowedList = filterAllowedIndices(logger, filter, pdus, allowedList)
allowedList = filterAllowedIndices(logger, filter, pdus, allowedList, metrics)

// Update config to get only index and not walk them.
newWalk = updateWalkConfig(newWalk, filter, logger)
Expand Down Expand Up @@ -272,12 +242,12 @@ func ScrapeTarget(ctx context.Context, target string, auth *config.Auth, module
return results, nil
}

func filterAllowedIndices(logger log.Logger, filter config.DynamicFilter, pdus []gosnmp.SnmpPDU, allowedList []string) []string {
func filterAllowedIndices(logger log.Logger, filter config.DynamicFilter, pdus []gosnmp.SnmpPDU, allowedList []string, metrics internalMetrics) []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")
snmpval := pduValueAsString(&pdu, "DisplayString", metrics)
level.Debug(logger).Log("config value", val, "snmp value", snmpval)

if regexp.MustCompile(val).MatchString(snmpval) {
Expand Down Expand Up @@ -366,16 +336,64 @@ func buildMetricTree(metrics []*config.Metric) *MetricNode {
return metricTree
}

type internalMetrics struct {
snmpUnexpectedPduType prometheus.Counter
snmpDuration prometheus.Histogram
snmpPackets prometheus.Counter
snmpRetries prometheus.Counter
}

type collector struct {
ctx context.Context
target string
auth *config.Auth
module *config.Module
logger log.Logger
ctx context.Context
target string
auth *config.Auth
module *config.Module
logger log.Logger
metrics internalMetrics
}

func newInternalMetrics(reg prometheus.Registerer) internalMetrics {
buckets := prometheus.ExponentialBuckets(0.0001, 2, 15)
snmpUnexpectedPduType := promauto.With(reg).NewCounter(
prometheus.CounterOpts{
Namespace: namespace,
Name: "unexpected_pdu_type_total",
Help: "Unexpected Go types in a PDU.",
},
)
snmpDuration := promauto.With(reg).NewHistogram(
prometheus.HistogramOpts{
Namespace: namespace,
Name: "packet_duration_seconds",
Help: "A histogram of latencies for SNMP packets.",
Buckets: buckets,
},
)
snmpPackets := promauto.With(reg).NewCounter(
prometheus.CounterOpts{
Namespace: namespace,
Name: "packets_total",
Help: "Number of SNMP packet sent, including retries.",
},
)
snmpRetries := promauto.With(reg).NewCounter(
prometheus.CounterOpts{
Namespace: namespace,
Name: "packet_retries_total",
Help: "Number of SNMP packet retries.",
},
)
return internalMetrics{
snmpUnexpectedPduType: snmpUnexpectedPduType,
snmpDuration: snmpDuration,
snmpPackets: snmpPackets,
snmpRetries: snmpRetries,
}
}

func New(ctx context.Context, target string, auth *config.Auth, module *config.Module, logger log.Logger) *collector {
return &collector{ctx: ctx, target: target, auth: auth, module: module, logger: logger}
func New(ctx context.Context, target string, auth *config.Auth, module *config.Module, logger log.Logger, reg prometheus.Registerer) *collector {
internalMetrics := newInternalMetrics(reg)
return &collector{ctx: ctx, target: target, auth: auth, module: module, logger: logger, metrics: internalMetrics}
}

// Describe implements Prometheus.Collector.
Expand All @@ -386,7 +404,7 @@ func (c collector) Describe(ch chan<- *prometheus.Desc) {
// Collect implements Prometheus.Collector.
func (c collector) Collect(ch chan<- prometheus.Metric) {
start := time.Now()
results, err := ScrapeTarget(c.ctx, c.target, c.auth, c.module, c.logger)
results, err := ScrapeTarget(c.ctx, c.target, c.auth, c.module, c.logger, c.metrics)
if err != nil {
level.Info(c.logger).Log("msg", "Error scraping target", "err", err)
ch <- prometheus.NewInvalidMetric(prometheus.NewDesc("snmp_error", "Error scraping target", nil, nil), err)
Expand Down Expand Up @@ -427,7 +445,7 @@ PduLoop:
}
if head.metric != nil {
// Found a match.
samples := pduToSamples(oidList[i+1:], &pdu, head.metric, oidToPdu, c.logger)
samples := pduToSamples(oidList[i+1:], &pdu, head.metric, oidToPdu, c.logger, c.metrics)
for _, sample := range samples {
ch <- sample
}
Expand Down Expand Up @@ -506,10 +524,10 @@ func parseDateAndTime(pdu *gosnmp.SnmpPDU) (float64, error) {
return float64(t.Unix()), nil
}

func pduToSamples(indexOids []int, pdu *gosnmp.SnmpPDU, metric *config.Metric, oidToPdu map[string]gosnmp.SnmpPDU, logger log.Logger) []prometheus.Metric {
func pduToSamples(indexOids []int, pdu *gosnmp.SnmpPDU, metric *config.Metric, oidToPdu map[string]gosnmp.SnmpPDU, logger log.Logger, metrics internalMetrics) []prometheus.Metric {
var err error
// The part of the OID that is the indexes.
labels := indexesToLabels(indexOids, metric, oidToPdu)
labels := indexesToLabels(indexOids, metric, oidToPdu, metrics)

value := getPduValue(pdu)
t := prometheus.UntypedValue
Expand Down Expand Up @@ -568,13 +586,13 @@ func pduToSamples(indexOids []int, pdu *gosnmp.SnmpPDU, metric *config.Metric, o
}

if len(metric.RegexpExtracts) > 0 {
return applyRegexExtracts(metric, pduValueAsString(pdu, metricType), labelnames, labelvalues, logger)
return applyRegexExtracts(metric, pduValueAsString(pdu, metricType, metrics), labelnames, labelvalues, logger)
}
// For strings we put the value as a label with the same name as the metric.
// If the name is already an index, we do not need to set it again.
if _, ok := labels[metric.Name]; !ok {
labelnames = append(labelnames, metric.Name)
labelvalues = append(labelvalues, pduValueAsString(pdu, metricType))
labelvalues = append(labelvalues, pduValueAsString(pdu, metricType, metrics))
}
}

Expand Down Expand Up @@ -710,7 +728,7 @@ func splitOid(oid []int, count int) ([]int, []int) {
}

// This mirrors decodeValue in gosnmp's helper.go.
func pduValueAsString(pdu *gosnmp.SnmpPDU, typ string) string {
func pduValueAsString(pdu *gosnmp.SnmpPDU, typ string, metrics internalMetrics) string {
switch pdu.Value.(type) {
case int:
return strconv.Itoa(pdu.Value.(int))
Expand Down Expand Up @@ -748,7 +766,7 @@ func pduValueAsString(pdu *gosnmp.SnmpPDU, typ string) string {
return ""
default:
// This shouldn't happen.
snmpUnexpectedPduType.Inc()
metrics.snmpUnexpectedPduType.Inc()
return fmt.Sprintf("%s", pdu.Value)
}
}
Expand Down Expand Up @@ -858,7 +876,7 @@ func indexOidsAsString(indexOids []int, typ string, fixedSize int, implied bool,
}
}

func indexesToLabels(indexOids []int, metric *config.Metric, oidToPdu map[string]gosnmp.SnmpPDU) map[string]string {
func indexesToLabels(indexOids []int, metric *config.Metric, oidToPdu map[string]gosnmp.SnmpPDU, metrics internalMetrics) map[string]string {
labels := map[string]string{}
labelOids := map[string][]int{}

Expand All @@ -884,7 +902,7 @@ func indexesToLabels(indexOids []int, metric *config.Metric, oidToPdu map[string
oid = fmt.Sprintf("%s.%s", oid, listToOid(labelOids[label]))
}
if pdu, ok := oidToPdu[oid]; ok {
labels[lookup.Labelname] = pduValueAsString(&pdu, lookup.Type)
labels[lookup.Labelname] = pduValueAsString(&pdu, lookup.Type, metrics)
labelOids[lookup.Labelname] = []int{int(gosnmp.ToBigInt(pdu.Value).Int64())}
} else {
labels[lookup.Labelname] = ""
Expand Down
10 changes: 5 additions & 5 deletions collector/collector_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -23,7 +23,7 @@ import (
kingpin "github.com/alecthomas/kingpin/v2"
"github.com/go-kit/log"
"github.com/gosnmp/gosnmp"
"github.com/prometheus/client_model/go"
io_prometheus_client "github.com/prometheus/client_model/go"

"github.com/prometheus/snmp_exporter/config"
)
Expand Down Expand Up @@ -518,7 +518,7 @@ func TestPduToSample(t *testing.T) {
}

for _, c := range cases {
metrics := pduToSamples(c.indexOids, c.pdu, c.metric, c.oidToPdu, log.NewNopLogger())
metrics := pduToSamples(c.indexOids, c.pdu, c.metric, c.oidToPdu, log.NewNopLogger(), internalMetrics{})
metric := &io_prometheus_client.Metric{}
expected := map[string]struct{}{}
for _, e := range c.expectedMetrics {
Expand Down Expand Up @@ -721,7 +721,7 @@ func TestPduValueAsString(t *testing.T) {
},
}
for _, c := range cases {
got := pduValueAsString(c.pdu, c.typ)
got := pduValueAsString(c.pdu, c.typ, internalMetrics{})
if !reflect.DeepEqual(got, c.result) {
t.Errorf("pduValueAsString(%v, %q): got %q, want %q", c.pdu, c.typ, got, c.result)
}
Expand Down Expand Up @@ -1008,7 +1008,7 @@ func TestIndexesToLabels(t *testing.T) {
},
}
for _, c := range cases {
got := indexesToLabels(c.oid, &c.metric, c.oidToPdu)
got := indexesToLabels(c.oid, &c.metric, c.oidToPdu, internalMetrics{})
if !reflect.DeepEqual(got, c.result) {
t.Errorf("indexesToLabels(%v, %v, %v): got %v, want %v", c.oid, c.metric, c.oidToPdu, got, c.result)
}
Expand Down Expand Up @@ -1059,7 +1059,7 @@ func TestFilterAllowedIndices(t *testing.T) {
},
}
for _, c := range cases {
got := filterAllowedIndices(log.NewNopLogger(), c.filter, pdus, c.allowedList)
got := filterAllowedIndices(log.NewNopLogger(), c.filter, pdus, c.allowedList, internalMetrics{})
if !reflect.DeepEqual(got, c.result) {
t.Errorf("filterAllowedIndices(%v): got %v, want %v", c.filter, got, c.result)
}
Expand Down
2 changes: 1 addition & 1 deletion main.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -124,7 +124,7 @@ func handler(w http.ResponseWriter, r *http.Request, logger log.Logger) {

start := time.Now()
registry := prometheus.NewRegistry()
c := collector.New(r.Context(), target, auth, module, logger)
c := collector.New(r.Context(), target, auth, module, logger, registry)
registry.MustRegister(c)
// Delegate http serving to Prometheus client library, which will call collector.Collect.
h := promhttp.HandlerFor(registry, promhttp.HandlerOpts{})
Expand Down

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