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AWS Fundamentals
L1 ConstructAWS::EC2::FlowLog

CfnFlowLog

Specifies a VPC flow log that captures IP traffic for a specified network interface, subnet, or VPC. To view the log data, use Amazon CloudWatch Logs (CloudWatch Logs) to help troubleshoot connection issues. For example, you can use a flow log to investigate why certain traffic isn't reaching an instance, which can help you diagnose overly restrictive security group rules. For more information, see [VPC Flow Logs](https://docs.aws.amazon.com/vpc/latest/userguide/flow-logs.html) in the *Amazon VPC User Guide* .

Import

import { CfnFlowLog } from 'aws-cdk-lib/aws-ec2';

Or use the module namespace:

import * as ec2 from 'aws-cdk-lib/aws-ec2';
// ec2.CfnFlowLog

Properties

Configuration passed to the constructor as CfnFlowLogProps.

resourceIdRequired
string | ISubnetRef | ITransitGatewayRef | IVPCRef

The ID of the resource to monitor. For example, if the resource type is `VPC` , specify the ID of the VPC.

resourceTypeRequired
string

The type of resource to monitor.

deliverCrossAccountRoleOptional
string

The ARN of the IAM role that allows the service to publish flow logs across accounts.

deliverLogsPermissionArnOptional
string | IRoleRef

The ARN of the IAM role that allows Amazon EC2 to publish flow logs to the log destination. This parameter is required if the destination type is `cloud-watch-logs` , or if the destination type is `kinesis-data-firehose` and the delivery stream and the resources to monitor are in different accounts.

destinationOptionsOptional
any

The destination options.

logDestinationOptional
string | ILogGroupRef | IBucketRef

The destination for the flow log data. The meaning of this parameter depends on the destination type. - If the destination type is `cloud-watch-logs` , specify the ARN of a CloudWatch Logs log group. For example: arn:aws:logs: *region* : *account_id* :log-group: *my_group* Alternatively, use the `LogGroupName` parameter. - If the destination type is `s3` , specify the ARN of an S3 bucket. For example: arn:aws:s3::: *my_bucket* / *my_subfolder* / The subfolder is optional. Note that you can't use `AWSLogs` as a subfolder name. - If the destination type is `kinesis-data-firehose` , specify the ARN of a Kinesis Data Firehose delivery stream. For example: arn:aws:firehose: *region* : *account_id* :deliverystream: *my_stream*

logDestinationTypeOptional
string

The type of destination for the flow log data. Default: `cloud-watch-logs`

logFormatOptional
string

The fields to include in the flow log record, in the order in which they should appear. If you omit this parameter, the flow log is created using the default format. If you specify this parameter, you must include at least one field. For more information about the available fields, see [Flow log records](https://docs.aws.amazon.com/vpc/latest/userguide/flow-logs.html#flow-log-records) in the *Amazon VPC User Guide* or [Transit Gateway Flow Log records](https://docs.aws.amazon.com/vpc/latest/tgw/tgw-flow-logs.html#flow-log-records) in the *AWS Transit Gateway Guide* . Specify the fields using the `${field-id}` format, separated by spaces.

logGroupNameOptional
string | ILogGroupRef

The name of a new or existing CloudWatch Logs log group where Amazon EC2 publishes your flow logs. This parameter is valid only if the destination type is `cloud-watch-logs` .

maxAggregationIntervalOptional
number

The maximum interval of time during which a flow of packets is captured and aggregated into a flow log record. The possible values are 60 seconds (1 minute) or 600 seconds (10 minutes). This parameter must be 60 seconds for transit gateway resource types. When a network interface is attached to a [Nitro-based instance](https://docs.aws.amazon.com/ec2/latest/instancetypes/ec2-nitro-instances.html) , the aggregation interval is always 60 seconds or less, regardless of the value that you specify. Default: 600

tagsOptional
CfnTag[]

The tags to apply to the flow logs.

trafficTypeOptional
string

The type of traffic to monitor (accepted traffic, rejected traffic, or all traffic). This parameter is not supported for transit gateway resource types. It is required for the other resource types.

CloudFormation Resource

This L1 construct maps directly to the following CloudFormation resource type.

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