add AWS/NATGateway metrics (#9202)

pkg/api/cloudwatch/metrics.go

@@ -78,6 +78,7 @@ func init() {
 		"AWS/Lambda":           {"Invocations", "Errors", "Duration", "Throttles", "IteratorAge"},
 		"AWS/Logs":             {"IncomingBytes", "IncomingLogEvents", "ForwardedBytes", "ForwardedLogEvents", "DeliveryErrors", "DeliveryThrottling"},
 		"AWS/ML":               {"PredictCount", "PredictFailureCount"},
+		"AWS/NATGateway":       {"PacketsOutToDestination", "PacketsOutToSource", "PacketsInFromSource", "PacketsInFromDestination", "BytesOutToDestination", "BytesOutToSource", "BytesInFromSource", "BytesInFromDestination", "ErrorPortAllocation", "ActiveConnectionCount", "ConnectionAttemptCount", "ConnectionEstablishedCount", "IdleTimeoutCount", "PacketsDropCount"},
 		"AWS/OpsWorks":         {"cpu_idle", "cpu_nice", "cpu_system", "cpu_user", "cpu_waitio", "load_1", "load_5", "load_15", "memory_buffers", "memory_cached", "memory_free", "memory_swap", "memory_total", "memory_used", "procs"},
 		"AWS/Redshift":         {"CPUUtilization", "DatabaseConnections", "HealthStatus", "MaintenanceMode", "NetworkReceiveThroughput", "NetworkTransmitThroughput", "PercentageDiskSpaceUsed", "ReadIOPS", "ReadLatency", "ReadThroughput", "WriteIOPS", "WriteLatency", "WriteThroughput"},
 		"AWS/RDS":              {"ActiveTransactions", "AuroraBinlogReplicaLag", "AuroraReplicaLag", "AuroraReplicaLagMaximum", "AuroraReplicaLagMinimum", "BinLogDiskUsage", "BlockedTransactions", "BufferCacheHitRatio", "CommitLatency", "CommitThroughput", "BinLogDiskUsage", "CPUCreditBalance", "CPUCreditUsage", "CPUUtilization", "DatabaseConnections", "DDLLatency", "DDLThroughput", "Deadlocks", "DeleteLatency", "DeleteThroughput", "DiskQueueDepth", "DMLLatency", "DMLThroughput", "EngineUptime", "FailedSqlStatements", "FreeableMemory", "FreeLocalStorage", "FreeStorageSpace", "InsertLatency", "InsertThroughput", "LoginFailures", "NetworkReceiveThroughput", "NetworkTransmitThroughput", "NetworkThroughput", "Queries", "ReadIOPS", "ReadLatency", "ReadThroughput", "ReplicaLag", "ResultSetCacheHitRatio", "SelectLatency", "SelectThroughput", "SwapUsage", "TotalConnections", "UpdateLatency", "UpdateThroughput", "VolumeBytesUsed", "VolumeReadIOPS", "VolumeWriteIOPS", "WriteIOPS", "WriteLatency", "WriteThroughput"},
@@ -122,6 +123,7 @@ func init() {
 		"AWS/Lambda":           {"FunctionName", "Resource", "Version", "Alias"},
 		"AWS/Logs":             {"LogGroupName", "DestinationType", "FilterName"},
 		"AWS/ML":               {"MLModelId", "RequestMode"},
+		"AWS/NATGateway":       {"NatGatewayId"},
 		"AWS/OpsWorks":         {"StackId", "LayerId", "InstanceId"},
 		"AWS/Redshift":         {"NodeID", "ClusterIdentifier"},
 		"AWS/RDS":              {"DBInstanceIdentifier", "DBClusterIdentifier", "DatabaseClass", "EngineName", "Role"},