Logging data events for trails - AWS CloudTrail

Logging data events for trails

By default, trails do not log data events. Additional charges apply for data events. For more information, see AWS CloudTrail Pricing.

Note

The events that are logged by your trails are available in Amazon CloudWatch Events. For example, if you configure a trail to log data events for S3 objects but not management events, your trail processes and logs only data events for the specified S3 objects. The data events for these S3 objects are available in Amazon CloudWatch Events. For more information, see AWS API Call Events in the Amazon CloudWatch Events User Guide.

Data events

Data events provide visibility into the resource operations performed on or within a resource. These are also known as data plane operations. Data events are often high-volume activities.

The following data types are recorded:

  • Amazon S3 object-level API activity (for example, GetObject, DeleteObject, and PutObject API operations)

  • AWS Lambda function execution activity (the Invoke API)

  • Amazon DynamoDB object-level API activity on tables (for example, PutItem, DeleteItem, and UpdateItem API operations).

  • S3 object-level API activity on AWS Outposts. This data type is only available with advanced event selectors.

  • Amazon Managed Blockchain JSON-RPC calls on Ethereum nodes, such as eth_getBalance or eth_getBlockByNumber. This data type is only available with advanced event selectors.

  • API activity on S3 Object Lambda access points, such as calls to CompleteMultipartUpload and GetObject. This data type is only available with advanced event selectors.

Data events are not logged by default when you create a trail. To record CloudTrail data events, you must explicitly add the supported resources or resource types for which you want to collect activity to a trail. For more information, see Creating a trail.

On a single-region trail, you can log data events only for resources that you can access in that region. Though S3 buckets are global, AWS Lambda functions and DynamoDB tables are regional.

Additional charges apply for logging data events. For CloudTrail pricing, see AWS CloudTrail Pricing.

Steps for logging data events depend on whether you have advanced event selectors enabled on your trail. Use the procedure in this section that matches the kind of event selectors you have enabled on a trail.

  1. Open the Trails page of the CloudTrail console and choose the trail name.

    Note

    While you can edit an existing trail to add logging data events, as a best practice, consider creating a separate trail specifically for logging data events.

  2. For Data events, choose Edit.

  3. For Amazon S3 buckets:

    1. For Data event source, choose S3.

    2. You can choose to log All current and future S3 buckets, or you can specify individual buckets or functions. By default, data events are logged for all current and future S3 buckets.

      Note

      Keeping the default All current and future S3 buckets option enables data event logging for all buckets currently in your AWS account and any buckets you create after you finish creating the trail. It also enables logging of data event activity performed by any user or role in your AWS account, even if that activity is performed on a bucket that belongs to another AWS account.

      If you are creating a trail for a single Region (done by using the AWS CLI), selecting the Select all S3 buckets in your account option enables data event logging for all buckets in the same Region as your trail and any buckets you create later in that Region. It will not log data events for Amazon S3 buckets in other Regions in your AWS account.

    3. If you leave the default, All current and future S3 buckets, choose to log Read events, Write events, or both.

    4. To select individual buckets, empty the Read and Write check boxes for All current and future S3 buckets. In Individual bucket selection, browse for a bucket on which to log data events. To find specific buckets, type a bucket prefix for the bucket you want. You can select multiple buckets in this window. Choose Add bucket to log data events for more buckets. Choose to log Read events, such as GetObject, Write events, such as PutObject, or both.

      This setting takes precedence over individual settings you configure for individual buckets. For example, if you specify logging Read events for all S3 buckets, and then choose to add a specific bucket for data event logging, Read is already selected for the bucket you added. You cannot clear the selection. You can only configure the option for Write.

      To remove a bucket from logging, choose X.

  4. To add another data type on which to log data events, choose Add data event type.

  5. For Lambda functions:

    1. For Data event source, choose Lambda.

    2. In Lambda function, choose All regions to log all Lambda functions, or Input function as ARN to log data events on a specific function.

      To log data events for all Lambda functions in your AWS account, select Log all current and future functions. This setting takes precedence over individual settings you configure for individual functions. All functions are logged, even if all functions are not displayed.

      Note

      If you are creating a trail for all Regions, this selection enables data event logging for all functions currently in your AWS account, and any Lambda functions you might create in any Region after you finish creating the trail. If you are creating a trail for a single Region (done by using the AWS CLI), this selection enables data event logging for all functions currently in that Region in your AWS account, and any Lambda functions you might create in that Region after you finish creating the trail. It does not enable data event logging for Lambda functions created in other Regions.

      Logging data events for all functions also enables logging of data event activity performed by any user or role in your AWS account, even if that activity is performed on a function that belongs to another AWS account.

    3. If you choose Input function as ARN, enter the ARN of a Lambda function.

      Note

      If you have more than 15,000 Lambda functions in your account, you cannot view or select all functions in the CloudTrail console when creating a trail. You can still select the option to log all functions, even if they are not displayed. If you want to log data events for specific functions, you can manually add a function if you know its ARN. You can also finish creating the trail in the console, and then use the AWS CLI and the put-event-selectors command to configure data event logging for specific Lambda functions. For more information, see Managing trails with the AWS CLI.

  6. To add another data type on which to log data events, choose Add data event type.

  7. For DynamoDB tables:

    1. For Data event source, choose DynamoDB.

    2. In DynamoDB table selection, choose Browse to select a table, or paste in the ARN of a DynamoDB table to which you have access. A DynamoDB table ARN is in the following format:

      arn:partition:dynamodb:region:account_ID:table/table_name

      To add another table, choose Add row, and browse for a table or paste in the ARN of a table to which you have access.

  8. Choose Update trail.

In the AWS Management Console, if you have advanced event selectors enabled, you can choose from predefined templates that log all data events on a selected resource (Amazon S3 buckets, Lambda functions, S3 objects on AWS Outposts, Ethereum for Managed Blockchain nodes, or S3 Object Lambda access points). After you choose a log selector template, you can customize the template to include only the data events you most want to see. For more information and tips about using advanced event selectors, see Log events by using advanced event selectors in this topic.

  1. On the Dashboard or Trails pages of the CloudTrail console, choose a trail name to open it.

  2. On the trail's details page, in Data events, choose Edit.

  3. If you are not already logging data events, choose the Data events check box.

  4. For Data event type, choose the data event resource type (S3 buckets, DynamoDBtables, S3 objects on AWS Outposts, Managed Blockchain nodes, S3 Object on Lambda access points, or Lambda functions) that you want to log.

  5. Choose a log selector template. CloudTrail includes predefined templates that log all data events for the resource type. To build a custom log selector template, choose Custom.

    Note

    Choosing a predefined template for S3 buckets enables data event logging for all buckets currently in your AWS account and any buckets you create after you finish creating the trail. It also enables logging of data event activity performed by any user or role in your AWS account, even if that activity is performed on a bucket that belongs to another AWS account.

    If the trail applies only to one Region, choosing a predefined template that logs all S3 buckets enables data event logging for all buckets in the same Region as your trail and any buckets you create later in that Region. It will not log data events for Amazon S3 buckets in other Regions in your AWS account.

    If you are creating a trail for all Regions, choosing a predefined template for Lambda functions enables data event logging for all functions currently in your AWS account, and any Lambda functions you might create in any Region after you finish creating the trail. If you are creating a trail for a single Region (done by using the AWS CLI), this selection enables data event logging for all functions currently in that Region in your AWS account, and any Lambda functions you might create in that Region after you finish creating the trail. It does not enable data event logging for Lambda functions created in other Regions.

    Logging data events for all functions also enables logging of data event activity performed by any user or role in your AWS account, even if that activity is performed on a function that belongs to another AWS account.

  6. If you want to apply a predefined log selector template, and you do not want to add another data event resource type, choose Save changes. You do not need to follow the rest of this procedure. To apply a custom log selector template, go on to the next step.

  7. To create a custom log selector template, in the Log selector template drop-down list, choose Custom.

  8. (Optional) Enter a name for your custom log selector template.

  9. In Advanced event selectors, build an expression for the specific S3 buckets, DynamoDBtables, S3 objects on AWS Outposts, S3 Object on Lambda access points, Managed Blockchain nodes, or Lambda functions on which you want to collect data events.

    1. Choose from the following fields. For fields that accept an array (more than one value), CloudTrail adds an OR between values.

      • readOnly - readOnly can be set to Equals a value of true or false. Read-only data events are events that do not change the state of a resource, such as Get* or Describe* events. Write events add, change, or delete resources, attributes, or artifacts, such as Put*, Delete*, or Write* events.

      • eventName - eventName can use any operator. You can use it to include or exclude any data event logged to CloudTrail, such as PutBucket or GetItem. You can have multiple values for this field, separated by commas.

      • resources.type - In the console, this field doesn't occur, because it's already populated by your choice of data event type from the Data event type drop-down list. In the AWS CLI and SDKs, resources.type can only use the Equals operator, and the value can be one of the following: AWS::S3::Object, AWS::S3Outposts::Object, AWS::Lambda::Function, AWS::DynamoDB::Table, AWS::ManagedBlockchain::Node, or AWS::S3ObjectLambda::AccessPoint.

      • resources.ARN - You can use any operator with resources.ARN, but if you use Equals or NotEquals, the value must exactly match the ARN of a valid resource of the type you've specified in the template as the value of resources.type. For example, if resources.type equals AWS::S3::Object, the ARN must be in one of the following formats. To log all data events for all objects in a specific S3 bucket, use the StartsWith operator, and include only the bucket ARN as the matching value.

        The trailing slash is intentional; do not exclude it.

        arn:partition:s3:::bucket_name/ arn:partition:s3:::bucket_name/object_or_file_name/

        When resources.type equals AWS::S3Outposts::Object, and the operator is set to Equals or NotEquals, the ARN must be in the following format:

        arn:partition:s3-outposts:region:account_ID:object_path

        When resources.type equals AWS::Lambda::Function, and the operator is set to Equals or NotEquals, the ARN must be in the following format:

        arn:partition:lambda:region:account_ID:function:function_name

        When resources.type equals AWS::DynamoDB::Table, and the operator is set to Equals or NotEquals, the ARN must be in the following format:

        arn:partition:dynamodb:region:account_ID:table/table_name

        When resources.type equals AWS::ManagedBlockchain::Node, and the operator is set to Equals or NotEquals, the ARN must be in the following format:

        arn:partition:managedblockchain:region:account_ID:nodes/node_ID

        When resources.type equals AWS::S3ObjectLambda::AccessPoint, and the operator is set to Equals or NotEquals, the ARN must be in the following format:

        arn:partition:s3-object-lambda:region:account_ID:accesspoint/access_point_name

      For more information about the ARN formats of data event resources, see Resource types defined by Amazon S3, Resource types defined by AWS Lambda, and Resource types defined by Amazon DynamoDB in the AWS Identity and Access Management User Guide.

    2. For each field, choose + Conditions to add as many conditions as you need, up to a maximum of 500 specified values for all conditions. For example, to exclude data events for two S3 buckets from data events that are logged on your trail, you can set the field to resources.ARN, set the operator for NotEquals, and then either paste in an S3 bucket ARN, or browse for the S3 buckets for which you do not want to log events.

      To add the second S3 bucket, choose + Conditions, and then repeat the preceding instruction, pasting in the ARN for or browsing for a different bucket.

      Note

      You can have a maximum of 500 values for all selectors on a trail. This includes arrays of multiple values for a selector such as eventName. If you have single values for all selectors, you can have a maximum of 500 conditions added to a selector.

      If you have more than 15,000 Lambda functions in your account, you cannot view or select all functions in the CloudTrail console when creating a trail. You can still log all functions with a predefined selector template, even if they are not displayed. If you want to log data events for specific functions, you can manually add a function if you know its ARN. You can also finish creating the trail in the console, and then use the AWS CLI and the put-event-selectors command to configure data event logging for specific Lambda functions. For more information, see Managing trails with the AWS CLI.

    3. Choose + Field to add additional fields as required. To avoid errors, do not set conflicting or duplicate values for fields. For example, do not specify an ARN in one selector to be equal to a value, then specify that the ARN not equal the same value in another selector.

    4. Save changes to your custom selector template by choosing Next. Do not choose another log selector template, or leave this page, or your custom selectors will be lost.

  10. To add another data type on which to log data events, choose Add data event type. Repeat steps 4 through this step to configure advanced event selectors for the data event type.

  11. After you choose Next, in Step 2: Choose log events, review the log selector template options you've chosen. Choose Edit to go back and make changes.

  12. After you've reviewed and verified your choices, choose Update trail if this is an existing trail, or Create trail if you are creating a new trail.

Examples: Logging data events for Amazon S3 Objects

Logging data events for all S3 objects in an S3 bucket

The following example demonstrates how logging works when you configure logging of all data events for an S3 bucket named bucket-1. In this example, the CloudTrail user specified an empty prefix, and the option to log both Read and Write data events.

  1. A user uploads an object to bucket-1.

  2. The PutObject API operation is an Amazon S3 object-level API. It is recorded as a data event in CloudTrail. Because the CloudTrail user specified an S3 bucket with an empty prefix, events that occur on any object in that bucket are logged. The trail processes and logs the event.

  3. Another user uploads an object to bucket-2.

  4. The PutObject API operation occurred on an object in an S3 bucket that wasn't specified for the trail. The trail doesn't log the event.

Logging data events for specific S3 objects

The following example demonstrates how logging works when you configure a trail to log events for specific S3 objects. In this example, the CloudTrail user specified an S3 bucket named bucket-3, with the prefix my-images, and the option to log only Write data events.

  1. A user deletes an object that begins with the my-images prefix in the bucket, such as arn:aws:s3:::bucket-3/my-images/example.jpg.

  2. The DeleteObject API operation is an Amazon S3 object-level API. It is recorded as a Write data event in CloudTrail. The event occurred on an object that matches the S3 bucket and prefix specified in the trail. The trail processes and logs the event.

  3. Another user deletes an object with a different prefix in the S3 bucket, such as arn:aws:s3:::bucket-3/my-videos/example.avi.

  4. The event occurred on an object that doesn't match the prefix specified in your trail. The trail doesn't log the event.

  5. A user calls the GetObject API operation for the object, arn:aws:s3:::bucket-3/my-images/example.jpg.

  6. The event occurred on a bucket and prefix that are specified in the trail, but GetObject is a read-type Amazon S3 object-level API. It is recorded as a Read data event in CloudTrail, and the trail is not configured to log Read events. The trail doesn't log the event.

Note

If you are logging data events for specific Amazon S3 buckets, we recommend you do not use an Amazon S3 bucket for which you are logging data events to receive log files that you have specified in the data events section. Using the same Amazon S3 bucket causes your trail to log a data event each time log files are delivered to your Amazon S3 bucket. Log files are aggregated events delivered at intervals, so this is not a 1:1 ratio of event to log file; the event is logged in the next log file. For example, when the trail delivers logs, the PutObject event occurs on the S3 bucket. If the S3 bucket is also specified in the data events section, the trail processes and logs the PutObject event as a data event. That action is another PutObject event, and the trail processes and logs the event again. For more information, see How CloudTrail Works.

To avoid logging data events for the Amazon S3 bucket where you receive log files if you configure a trail to log all Amazon S3 data events in your AWS account, consider configuring delivery of log files to an Amazon S3 bucket that belongs to another AWS account. For more information, see Receiving CloudTrail Log Files from Multiple Accounts.

Logging data events for S3 objects in other AWS accounts

When you configure your trail to log data events, you can also specify S3 objects that belong to other AWS accounts. When an event occurs on a specified object, CloudTrail evaluates whether the event matches any trails in each account. If the event matches the settings for a trail, the trail processes and logs the event for that account. Generally, both API callers and resource owners can receive events.

If you own an S3 object and you specify it in your trail, your trail logs events that occur on the object in your account. Because you own the object, your trail also logs events when other accounts call the object.

If you specify an S3 object in your trail, and another account owns the object, your trail only logs events that occur on that object in your account. Your trail doesn't log events that occur in other accounts.

Example: Logging data events for an S3 object for two AWS accounts

The following example shows how two AWS accounts configure CloudTrail to log events for the same S3 object.

  1. In your account, you want your trail to log data events for all objects in your S3 bucket named owner-bucket. You configure the trail by specifying the S3 bucket with an empty object prefix.

  2. Bob has a separate account that has been granted access to the S3 bucket. Bob also wants to log data events for all objects in the same S3 bucket. For his trail, he configures his trail and specifies the same S3 bucket with an empty object prefix.

  3. Bob uploads an object to the S3 bucket with the PutObject API operation.

  4. This event occurred in his account and it matches the settings for his trail. Bob's trail processes and logs the event.

  5. Because you own the S3 bucket and the event matches the settings for your trail, your trail also processes and logs the same event. Because there are now two copies of the event (one logged in Bob's trail, and one logged in yours), CloudTrail charges for two copies of the data event.

  6. You upload an object to the S3 bucket.

  7. This event occurs in your account and it matches the settings for your trail. Your trail processes and logs the event.

  8. Because the event didn't occur in Bob's account, and he doesn't own the S3 bucket, Bob's trail doesn't log the event. CloudTrail charges for only one copy of this data event.

Example: Logging data events for all buckets, including an S3 bucket used by two AWS accounts

The following example shows the logging behavior when Select all S3 buckets in your account is enabled for trails that collect data events in an AWS account.

  1. In your account, you want your trail to log data events for all S3 buckets. You configure the trail by choosing Read events, Write events, or both for All current and future S3 buckets in Data events.

  2. Bob has a separate account that has been granted access to an S3 bucket in your account. He wants to log data events for the bucket to which he has access. He configures his trail to get data events for all S3 buckets.

  3. Bob uploads an object to the S3 bucket with the PutObject API operation.

  4. This event occurred in his account and it matches the settings for his trail. Bob's trail processes and logs the event.

  5. Because you own the S3 bucket and the event matches the settings for your trail, your trail also processes and logs the event. Because there are now two copies of the event (one logged in Bob's trail, and one logged in yours), CloudTrail charges each account for a copy of the data event.

  6. You upload an object to the S3 bucket.

  7. This event occurs in your account and it matches the settings for your trail. Your trail processes and logs the event.

  8. Because the event didn't occur in Bob's account, and he doesn't own the S3 bucket, Bob's trail doesn't log the event. CloudTrail charges for only one copy of this data event in your account.

  9. A third user, Mary, has access to the S3 bucket, and runs a GetObject operation on the bucket. She has a trail configured to log data events on all S3 buckets in her account. Because she is the API caller, CloudTrail logs a data event in her trail. Though Bob has access to the bucket, he is not the resource owner, so no event is logged in his trail this time. As the resource owner, you receive an event in your trail about the GetObject operation that Mary called. CloudTrail charges your account and Mary's account for each copy of the data event: one in Mary's trail, and one in yours.

Read-only and write-only events

When you configure your trail to log data and management events, you can specify whether you want read-only events, write-only events, or both.

  • Read

    Read events include API operations that read your resources, but don't make changes. For example, read-only events include the Amazon EC2 DescribeSecurityGroups and DescribeSubnets API operations. These operations return only information about your Amazon EC2 resources and don't change your configurations.

  • Write

    Write events include API operations that modify (or might modify) your resources. For example, the Amazon EC2 RunInstances and TerminateInstances API operations modify your instances.

Example: Logging read and write events for separate trails

The following example shows how you can configure trails to split log activity for an account into separate S3 buckets: one bucket receives read-only events and a second bucket receives write-only events.

  1. You create a trail and choose an S3 bucket named read-only-bucket to receive log files. You then update the trail to specify that you want Read management events and data events.

  2. You create a second trail and choose an S3 bucket named write-only-bucket to receive log files. You then update the trail to specify that you want Write management events and data events.

  3. The Amazon EC2 DescribeInstances and TerminateInstances API operations occur in your account.

  4. The DescribeInstances API operation is a read-only event and it matches the settings for the first trail. The trail logs and delivers the event to the read-only-bucket.

  5. The TerminateInstances API operation is a write-only event and it matches the settings for the second trail. The trail logs and delivers the event to the write-only-bucket.

Logging data events with the AWS Command Line Interface

You can configure your trails to log management and data events using the AWS CLI. To see whether your trail is logging management and data events, run the get-event-selectors command.

Note

Be aware that if your account is logging more than one copy of management events, you incur charges. There is always a charge for logging data events. For more information, see AWS CloudTrail Pricing.

aws cloudtrail get-event-selectors --trail-name TrailName

The command returns the default settings for a trail.

Log events by using basic event selectors

The following is an example result of the get-event-selectors command showing basic event selectors. By default, when you create a trail by using the AWS CLI, a trail logs all management events. By default, trails do not log data events.

{ "EventSelectors": [ { "IncludeManagementEvents": true, "DataResources": [], "ReadWriteType": "All" } ], "TrailARN": "arn:aws:cloudtrail:us-east-2:123456789012:trail/TrailName" }

To configure your trail to log management and data events, run the put-event-selectors command.

The following example shows how to use basic event selectors to configure your trail to include all management and data events for two S3 objects. You can specify from 1 to 5 event selectors for a trail. You can specify from 1 to 250 data resources for a trail.

Note

The maximum number of S3 data resources is 250, if you choose to limit data events by using basic event selectors.

aws cloudtrail put-event-selectors --trail-name TrailName --event-selectors '[{ "ReadWriteType": "All", "IncludeManagementEvents":true, "DataResources": [{ "Type": "AWS::S3::Object", "Values": ["arn:aws:s3:::mybucket/prefix", "arn:aws:s3:::mybucket2/prefix2"] }] }]'

The command returns the event selectors that are configured for the trail.

{ "EventSelectors": [ { "IncludeManagementEvents": true, "DataResources": [ { "Values": [ "arn:aws:s3:::mybucket/prefix", "arn:aws:s3:::mybucket2/prefix2", ], "Type": "AWS::S3::Object" } ], "ReadWriteType": "All" } ], "TrailARN": "arn:aws:cloudtrail:us-east-2:123456789012:trail/TrailName" }

Log events by using advanced event selectors

If you have opted to use advanced event selectors, the get-event-selectors command returns results similar to the following. By default, no advanced event selectors are configured for a trail.

{ "AdvancedEventSelectors": [], "TrailARN": "arn:aws:cloudtrail:us-east-2:123456789012:trail/TrailName" }

The following example shows how to use advanced event selectors to log all management events (both readOnly and writeOnly), and include PutObject and DeleteObject events for the S3 objects in the same two S3 bucket prefixes. As shown here, you can use advanced event selectors to select not only the S3 prefix names by ARN, but the names of the specific events that you want to log. You can add up to 500 conditions to advanced event selectors per trail, including all selector values. You can specify from 1 to 250 data resources for a trail.

aws cloudtrail put-event-selectors --trail-name TrailName \ --advanced-event-selectors '[ { "Name": "Log readOnly and writeOnly management events", "FieldSelectors": [ { "Field": "readOnly", "Equals": ["false"] }, { "Field": "eventCategory", "Equals": ["Management"] } ] }, { "Name": "Log PutObject and DeleteObject events for two S3 prefixes", "FieldSelectors": [ { "Field": "readOnly", "Equals": ["false"] }, { "Field": "eventCategory", "Equals": ["Data"] }, { "Field": "resources.type", "Equals": ["AWS::S3::Object"] }, { "Field": "eventName", "Equals": ["PutObject","DeleteObject"] }, { "Field": "resources.ARN", "StartsWith": ["arn:aws:s3:::mybucket/prefix","arn:aws:s3:::mybucket2/prefix2"] } ] } ]'

The result shows the advanced event selectors that are configured for the trail.

{ "AdvancedEventSelectors": [ { "Name": "Log readOnly and writeOnly management events", "FieldSelectors": [ { "Field": "readOnly", "Equals": [ false ], "StartsWith": [], "EndsWith": [], "NotEquals": [], "NotStartsWith": [], "NotEndsWith": [] }, { "Field": "eventCategory", "Equals": [ "Management" ], "StartsWith": [], "EndsWith": [], "NotEquals": [], "NotStartsWith": [], "NotEndsWith": [] } ] }, { "Name": "Log PutObject and DeleteObject events for two S3 prefixes", "FieldSelectors": [ { "Field": "readOnly", "Equals": [ false ], "StartsWith": [], "EndsWith": [], "NotEquals": [], "NotStartsWith": [], "NotEndsWith": [] }, { "Field": "eventCategory", "Equals": [ "Data" ], "StartsWith": [], "EndsWith": [], "NotEquals": [], "NotStartsWith": [], "NotEndsWith": [] }, { "Field": "resources.type", "Equals": [ "AWS::S3::Object" ], "StartsWith": [], "EndsWith": [], "NotEquals": [], "NotStartsWith": [], "NotEndsWith": [] }, { "Field": "resources.ARN", "Equals": [], "StartsWith": [ "arn:aws:s3:::mybucket/prefix","arn:aws:s3:::mybucket2/prefix2" ], "EndsWith": [], "Equals": [], "NotStartsWith": [], "NotEndsWith": [] } ] } ], "TrailARN": "arn:aws:cloudtrail:us-east-2:123456789012:trail/TrailName" }

Log all Amazon S3 events for a bucket by using advanced event selectors

The following example shows how to configure your trail to include all data events for all Amazon S3 objects in a specific S3 bucket. The value for S3 events for the resources.type field is AWS::S3::Object. Because the ARN values for S3 objects and S3 buckets are slightly different, add the StartsWith operator for resources.ARN to capture all events.

aws cloudtrail put-event-selectors --trail-name TrailName --region region \ --advanced-event-selectors \ '[ { "Name": "S3EventSelector", "FieldSelectors": [ { "Field": "eventCategory", "Equals": ["Data"] }, { "Field": "resources.type", "Equals": ["AWS::S3::Object"] }, { "Field": "resources.ARN", "StartsWith": ["arn:partition:s3:::bucket_name/"] } ] } ]'

The command returns the following example output.

{ "AdvancedEventSelectors": [ { "Name": "S3EventSelector", "FieldSelectors": [ { "Field": "eventCategory", "Equals": [ "Data" ] }, { "Field": "resources.type", "Equals": [ "AWS::S3::Object" ] }, { "Field": "resources.ARN", "StartsWith": [ "arn:partition:s3:::bucket_name/" ] } ] } ], "TrailARN": "arn:aws:cloudtrail:region:account_ID:trail/TrailName" }

Log Amazon S3 on AWS Outposts events by using advanced event selectors

The following example shows how to configure your trail to include all data events for all Amazon S3 on Outposts objects in your outpost. In this release, the supported value for S3 on Outposts events for the resources.type field is AWS::S3Outposts::Object.

aws cloudtrail put-event-selectors --trail-name TrailName --region region \ --advanced-event-selectors \ '[ { "Name": "OutpostsEventSelector", "FieldSelectors": [ { "Field": "eventCategory", "Equals": ["Data"] }, { "Field": "resources.type", "Equals": ["AWS::S3Outposts::Object"] } ] } ]'

The command returns the following example output.

{ "AdvancedEventSelectors": [ { "Name": "OutpostsEventSelector", "FieldSelectors": [ { "Field": "eventCategory", "Equals": [ "Data" ] }, { "Field": "resources.type", "Equals": [ "AWS::S3Outposts::Object" ] } ] } ], "TrailARN": "arn:aws:cloudtrail:region:account_ID:trail/TrailName" }

Logging events with the AWS SDKs

Run the GetEventSelectors operation to see whether your trail is logging data events for a trail. You can configure your trails to log data events by running the PutEventSelectors operation. For more information, see the AWS CloudTrail API Reference.

Sending events to Amazon CloudWatch Logs

CloudTrail supports sending data events to CloudWatch Logs. When you configure your trail to send events to your CloudWatch Logs log group, CloudTrail sends only the events that you specify in your trail. For example, if you configure your trail to log data events only, your trail delivers data events only to your CloudWatch Logs log group. For more information, see Monitoring CloudTrail Log Files with Amazon CloudWatch Logs.