Creating a Trail - AWS CloudTrail

Creating a Trail

Follow the procedure to create a trail that applies to all Regions. A trail that applies to all Regions delivers log files from all Regions to an S3 bucket. After you create the trail, AWS CloudTrail automatically starts logging the events that you specified.

Note

After you create a trail, you can configure other AWS services to further analyze and act upon the event data collected in CloudTrail logs. For more information, see CloudTrail Supported Services and Integrations.

Creating a Trail in the Console

In the console, you create a trail that logs events in all AWS Regions. This is a recommended best practice. To log events in a single region (not recommended), use the AWS CLI.

To create a CloudTrail trail with the AWS Management Console

  1. Sign in to the AWS Management Console and open the CloudTrail console at https://console.aws.amazon.com/cloudtrail/.

  2. On the CloudTrail service home page, the Trails page, or the Trails section of the Dashboard page, choose Create trail.

  3. On the Create Trail page, for Trail name, type a name for your trail. For more information, see CloudTrail Trail Naming Requirements.

  4. If this is an AWS Organizations organization trail, you can choose to enable the trail for all accounts in your organization. You only see this option if you are signed in to the console with an IAM user or role in the master account. To successfully create an organization trail, be sure that the user or role has sufficient permissions. For more information, see Creating a Trail for an Organization.

  5. For Storage location, choose Create new S3 bucket to create a bucket. When you create a bucket, CloudTrail creates and applies the required bucket policies.

    Note

    If you chose Use existing S3 bucket, specify a bucket in Trail log bucket name, or choose Browse to choose a bucket. The bucket policy must grant CloudTrail permission to write to it. For information about manually editing the bucket policy, see Amazon S3 Bucket Policy for CloudTrail.

    To make it easier to find your logs, create a new folder (also known as a prefix) in an existing bucket to store your CloudTrail logs. Enter the prefix in Prefix.

  6. For Log file SSE-KMS encryption, choose Enabled if you want to encrypt your log files with SSE-KMS instead of SSE-S3. The default is Enabled. For more information about this encryption type, see Protecting Data Using Server-Side Encryption with Amazon S3-Managed Encryption Keys (SSE-S3).

    If you enable SSE-KMS encryption, choose a New or Existing AWS KMS customer master key. In AWS KMS Alias, specify an alias, in the format alias/MyAliasName. For more information, see Updating a Trail to Use Your CMK.

    Note

    You can also type the ARN of a key from another account. For more information, see Updating a Trail to Use Your CMK. The key policy must allow CloudTrail to use the key to encrypt your log files, and allow the users you specify to read log files in unencrypted form. For information about manually editing the key policy, see Configure AWS KMS Key Policies for CloudTrail.

  7. In Additional settings, configure the following.

    1. For Log file validation, choose Enabled to have log digests delivered to your S3 bucket. You can use the digest files to verify that your log files did not change after CloudTrail delivered them. For more information, see Validating CloudTrail Log File Integrity.

    2. For SNS notification delivery, choose Enabled to be notified each time a log is delivered to your bucket. CloudTrail stores multiple events in a log file. SNS notifications are sent for every log file, not for every event. For more information, see Configuring Amazon SNS Notifications for CloudTrail.

      If you enable SNS notifications, for Create a new SNS topic, choose New to create a topic, or choose Existing to use an existing topic. If you are creating a trail that applies to all Regions, SNS notifications for log file deliveries from all Regions are sent to the single SNS topic that you create.

      If you choose New, CloudTrail specifies a name for the new topic for you, or you can type a name. If you choose Existing, choose an SNS topic from the drop-down list. You can also enter the ARN of a topic from another Region or from an account with appropriate permissions. For more information, see Amazon SNS Topic Policy for CloudTrail.

      If you create a topic, you must subscribe to the topic to be notified of log file delivery. You can subscribe from the Amazon SNS console. Due to the frequency of notifications, we recommend that you configure the subscription to use an Amazon SQS queue to handle notifications programmatically. For more information, see the Amazon Simple Notification Service Getting Started Guide.

  8. Optionally, configure CloudTrail to send log files to CloudWatch Logs by choosing Enabled in CloudWatch Logs. For more information, see Sending Events to CloudWatch Logs.

    1. If you enable integration with CloudWatch Logs, choose New to create a new log group, or Existing to use an existing one. If you choose New, CloudTrail specifies a name for the new log group for you, or you can type a name.

    2. If you choose Existing, choose a log group from the drop-down list.

    3. Choose New to create a new IAM role for permissions to send logs to CloudWatch Logs. Choose Existing to choose an existing IAM role from the drop-down list. The policy statement for the new or existing role is displayed when you expand Policy document. For more information about this role, see Role Policy Document for CloudTrail to Use CloudWatch Logs for Monitoring.

      Note

      When you configure a trail, you can choose an S3 bucket and SNS topic that belong to another account. However, if you want CloudTrail to deliver events to a CloudWatch Logs log group, you must choose a log group that exists in your current account.

  9. For Tags, add one or more custom tags (key-value pairs) to your trail. Tags can help you identify both your CloudTrail trails and the Amazon S3 buckets that contain CloudTrail log files. You can then use resource groups for your CloudTrail resources. For more information, see AWS Resource Groups and Why Use Tags For Trails?.

  10. On the Choose log events page, choose the event types that you want to log. By default, Management events is selected. For Management events, do the following.

    1. For API activity, choose if you want your trail to log Read events, Write events, or both. By default, trails log all management events. For more information, see Management Events.

    2. Choose Exclude AWS KMS events to filter AWS Key Management Service (AWS KMS) events out of your trail. The default setting is to include all AWS KMS events.

      The option to log or exclude AWS KMS events is available only if you log management events on your trail. If you choose not to log management events, AWS KMS events are not logged, and you cannot change AWS KMS event logging settings.

      AWS KMS actions such as Encrypt, Decrypt, and GenerateDataKey typically generate a large volume (more than 99%) of events. These actions are now logged as Read events. Low-volume, relevant AWS KMS actions such as Disable, Delete, and ScheduleKey (which typically account for less than 0.5% of AWS KMS event volume) are logged as Write events.

      To exclude high-volume events like Encrypt, Decrypt, and GenerateDataKey, but still log relevant events such as Disable, Delete and ScheduleKey, choose to log Write management events, and clear the check box for Exclude AWS KMS events.

  11. For Data events, you can specify logging data events for Amazon S3 buckets, for AWS Lambda functions, or both. By default, trails don't log data events. Additional charges apply for logging data events. For more information, see Data Events. For CloudTrail pricing, see AWS CloudTrail Pricing.

    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 the trail applies only to one Region, choosing All current and future 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.

    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. Filter a large number of buckets by typing 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.

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

  13. 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, type 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.

  14. Choose Insights events if you want your trail to log CloudTrail Insights events.

    In Event type, select Insights events. You must be logging Write management events to log Insights events.

    CloudTrail Insights analyzes management Write events for unusual activity, and logs events when anomalies are detected. By default, trails don't log Insights events. For more information about Insights events, see Logging Insights Events for Trails. Additional charges apply for logging Insights events. For CloudTrail pricing, see AWS CloudTrail Pricing.

    Insights events are delivered to a different folder named /CloudTrail-Insightof the same S3 bucket that is specified in the Storage location area of the trail details page. CloudTrail creates the new prefix for you. For example, if your current destination S3 bucket is named S3bucketName/AWSLogs/CloudTrail/, the S3 bucket name with a new prefix is named S3bucketName/AWSLogs/CloudTrail-Insight/.

  15. When you are finished choosing event types to log, choose Next.

  16. On the Review and create page, review your choices. Choose Edit in a section to change the trail settings shown in that section. When you are ready to create the trail, choose Create trail.

  17. The new trail appears on the Trails page. The Trails page shows the trails in your account from all Regions. In about 15 minutes, CloudTrail publishes log files that show the AWS API calls made in your account. You can see the log files in the S3 bucket that you specified. It can take up to 36 hours for CloudTrail to deliver the first Insights event, if you have enabled Insights event logging, and unusual activity is detected.

Note

You can't rename a trail after it has been created. Instead, you can delete the trail and create a new one.

Next Steps

After you create your trail, you can return to the trail to make changes: