[NDMII-3058] Add synchronous rDNS lookup to rdnsquerier component

cmd/agent/subcommands/run/command.go

@@ -155,6 +155,8 @@ import (
 	"github.com/DataDog/datadog-agent/pkg/util/optional"
 	"github.com/DataDog/datadog-agent/pkg/version"
 
+	rdnsquerier "github.com/DataDog/datadog-agent/comp/rdnsquerier/def"
+
 	// runtime init routines
 	ddruntime "github.com/DataDog/datadog-agent/pkg/runtime"
 )
@@ -255,6 +257,7 @@ func run(log log.Component,
 	settings settings.Component,
 	_ optional.Option[gui.Component],
 	_ agenttelemetry.Component,
+	rdnsquerier rdnsquerier.Component,
 ) error {
 	defer func() {
 		stopAgent()
@@ -319,6 +322,7 @@ func run(log log.Component,
 		cloudfoundrycontainer,
 		jmxlogger,
 		settings,
+		rdnsquerier,
 	); err != nil {
 		return err
 	}
@@ -494,6 +498,7 @@ func startAgent(
 	_ cloudfoundrycontainer.Component,
 	jmxLogger jmxlogger.Component,
 	settings settings.Component,
+	rdnsquerier rdnsquerier.Component,
 ) error {
 	var err error
 
@@ -571,6 +576,7 @@ func startAgent(
 
 	// TODO: (components) - Until the checks are components we set there context so they can depends on components.
 	check.InitializeInventoryChecksContext(invChecks)
+	check.InitializeRDNSQuerierContext(rdnsquerier)
 
 	// Init JMX runner and inject dogstatsd component
 	jmxfetch.InitRunner(server, jmxLogger)

pkg/cli/subcommands/check/command.go

@@ -65,6 +65,7 @@ import (
 	integrations "github.com/DataDog/datadog-agent/comp/logs/integrations/def"
 	"github.com/DataDog/datadog-agent/comp/metadata/inventorychecks"
 	"github.com/DataDog/datadog-agent/comp/metadata/inventorychecks/inventorychecksimpl"
+	rdnsquerier "github.com/DataDog/datadog-agent/comp/rdnsquerier/def"
 	"github.com/DataDog/datadog-agent/comp/remote-config/rcservice"
 	"github.com/DataDog/datadog-agent/comp/remote-config/rcservicemrf"
 	"github.com/DataDog/datadog-agent/comp/serializer/compression/compressionimpl"
@@ -264,6 +265,7 @@ func run(
 	jmxLogger jmxlogger.Component,
 	telemetry telemetry.Component,
 	logReceiver optional.Option[integrations.Component],
+	rdnsquerier rdnsquerier.Component,
 ) error {
 	previousIntegrationTracing := false
 	previousIntegrationTracingExhaustive := false
@@ -288,6 +290,8 @@ func run(
 
 	// TODO: (components) - Until the checks are components we set there context so they can depends on components.
 	check.InitializeInventoryChecksContext(invChecks)
+	check.InitializeRDNSQuerierContext(rdnsquerier)
+
 	pkgcollector.InitPython(common.GetPythonPaths()...)
 	commonchecks.RegisterChecks(wmeta, config, telemetry)
 

pkg/collector/check/context.go

@@ -10,6 +10,7 @@ import (
 	"sync"
 
 	"github.com/DataDog/datadog-agent/comp/metadata/inventorychecks"
+	rdnsquerier "github.com/DataDog/datadog-agent/comp/rdnsquerier/def"
 )
 
 // checkContext holds a list of reference to different components used by Go and Python checks.
@@ -20,7 +21,8 @@ import (
 // of C to Go. This way python checks can submit metadata to inventorychecks through the 'SetCheckMetadata' python
 // method.
 type checkContext struct {
-	ic inventorychecks.Component
+	ic          inventorychecks.Component
+	rdnsquerier rdnsquerier.Component
 }
 
 var ctx checkContext
@@ -47,10 +49,32 @@ func InitializeInventoryChecksContext(ic inventorychecks.Component) {
 	}
 }
 
+// GetRDNSQuerierContext returns a reference to the rdnsquerier component for Python and Go checks to use.
+func GetRDNSQuerierContext() (rdnsquerier.Component, error) {
+	checkContextMutex.Lock()
+	defer checkContextMutex.Unlock()
+
+	if ctx.rdnsquerier == nil {
+		return nil, errors.New("rdnsquerier context was not set")
+	}
+	return ctx.rdnsquerier, nil
+}
+
+// InitializeRDNSQuerierContext set the reference to rdnsquerier in checkContext
+func InitializeRDNSQuerierContext(rdnsquerier rdnsquerier.Component) {
+	checkContextMutex.Lock()
+	defer checkContextMutex.Unlock()
+
+	if ctx.rdnsquerier == nil {
+		ctx.rdnsquerier = rdnsquerier
+	}
+}
+
 // ReleaseContext reset to nil all the references hold by the current context
 func ReleaseContext() {
 	checkContextMutex.Lock()
 	defer checkContextMutex.Unlock()
 
 	ctx.ic = nil
+	ctx.rdnsquerier = nil
 }

pkg/collector/corechecks/snmp/internal/report/report_device_metadata.go

@@ -11,6 +11,7 @@ import (
 	"sort"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/DataDog/datadog-agent/comp/forwarder/eventplatform"
@@ -21,6 +22,7 @@ import (
 	"github.com/DataDog/datadog-agent/pkg/networkdevice/profile/profiledefinition"
 	"github.com/DataDog/datadog-agent/pkg/networkdevice/utils"
 
+	"github.com/DataDog/datadog-agent/pkg/collector/check"
 	"github.com/DataDog/datadog-agent/pkg/collector/corechecks/snmp/internal/checkconfig"
 	"github.com/DataDog/datadog-agent/pkg/collector/corechecks/snmp/internal/common"
 	"github.com/DataDog/datadog-agent/pkg/collector/corechecks/snmp/internal/lldp"
@@ -214,6 +216,8 @@ func buildNetworkDeviceMetadata(deviceID string, idTags []string, config *checkc
 		vendor = config.ProfileDef.Device.Vendor
 	}
 
+	hostname := lookupHostnameWithRDNS(config.IPAddress)
+
 	return devicemetadata.DeviceMetadata{
 		ID:             deviceID,
 		IDTags:         idTags,
@@ -238,9 +242,37 @@ func buildNetworkDeviceMetadata(deviceID string, idTags []string, config *checkc
 		OsHostname:     osHostname,
 		DeviceType:     deviceType,
 		Integration:    common.SnmpIntegrationName,
+		RDNSHostname:   hostname,
 	}
 }
 
+func lookupHostnameWithRDNS(ip string) string {
+	if rdnsquerier, err := check.GetRDNSQuerierContext(); err == nil {
+		var hostname string
+		var wg sync.WaitGroup
+
+		wg.Add(1)
+		err := rdnsquerier.GetHostname(
+			net.ParseIP(ip).To4(),
+			func(h string) {
+				hostname = h
+				wg.Done()
+			},
+			func(h string, err error) {
+				hostname = h
+				wg.Done()
+			},
+		)
+		if err != nil {
+			log.Tracef("Error resolving reverse DNS enrichment for source IP address: %v error: %v", ip, err)
+			wg.Done()
+		}
+		wg.Wait()
+		return hostname
+	}
+	return ""
+}
+
 func getProfileVersion(config *checkconfig.CheckConfig) uint64 {
 	var profileVersion uint64
 	if config.ProfileDef != nil {

pkg/networkdevice/metadata/payload.go

@@ -73,6 +73,7 @@ type DeviceMetadata struct {
 	OsHostname     string       `json:"os_hostname,omitempty"`
 	Integration    string       `json:"integration,omitempty"` // indicates the source of the data SNMP, meraki_api, etc.
 	DeviceType     string       `json:"device_type,omitempty"`
+	RDNSHostname   string       `json:"rdns_hostname,omitempty"`
 }
 
 // DeviceOID device scan oid data