AWS::Logs::AccountPolicy

Creates or updates an account-level data protection policy or subscription filter policy that applies to all log groups or a subset of log groups in the account.

Data protection policy

A data protection policy can help safeguard sensitive data that's ingested by your log groups by auditing and masking the sensitive log data. Each account can have only one account-level data protection policy.

If you create a data protection policy for your whole account, it applies to both existing log groups and all log groups that are created later in this account. The account policy is applied to existing log groups with eventual consistency. It might take up to 5 minutes before sensitive data in existing log groups begins to be masked.

By default, when a user views a log event that includes masked data, the sensitive data is replaced by asterisks. A user who has the logs:Unmask permission can use a GetLogEvents or FilterLogEvents operation with the unmask parameter set to true to view the unmasked log events. Users with the logs:Unmask can also view unmasked data in the CloudWatch Logs console by running a CloudWatch Logs Insights query with the unmask query command.

For more information, including a list of types of data that can be audited and masked, see Protect sensitive log data with masking.

To create an account-level policy, you must be signed on with the logs:PutDataProtectionPolicy and logs:PutAccountPolicy permissions.

An account-level policy applies to all log groups in the account. You can also create a data protection policy that applies to just one log group. If a log group has its own data protection policy and the account also has an account-level data protection policy, then the two policies are cumulative. Any sensitive term specified in either policy is masked.

Subscription filter policy

A subscription filter policy sets up a real-time feed of log events from CloudWatch Logs to other AWS services. Account-level subscription filter policies apply to both existing log groups and log groups that are created later in this account. Supported destinations are Kinesis Data Streams, Firehose, and Lambda. When log events are sent to the receiving service, they are Base64 encoded and compressed with the GZIP format.

The following destinations are supported for subscription filters:

Each account can have one account-level subscription filter policy. If you are updating an existing filter, you must specify the correct name in PolicyName. To perform a PutAccountPolicy subscription filter operation for any destination except a Lambda function, you must also have the iam:PassRole permission.

Field index policy

You can use field index policies to create indexes on fields found in log events in the log group. Creating field indexes lowers the scan volume for CloudWatch Logs Insights queries that reference those fields, because these queries attempt to skip the processing of log events that are known to not match the indexed field. Good fields to index are fields that you often need to query for. Common examples of indexes include request ID, session ID, user IDs, or instance IDs. For more information, see Create field indexes to improve query performance and reduce costs

For example, suppose you have created a field index for requestId. Then, any CloudWatch Logs Insights query on that log group that includes requestId = value or requestId IN [value, value, ...] will attempt to process only the log events where the indexed field matches the specified value.

Matches of log events to the names of indexed fields are case-sensitive. For example, an indexed field of RequestId won't match a log event containing requestId.

You can have one account-level field index policy that applies to all log groups in the account. Or you can create as many as 20 account-level field index policies that are each scoped to a subset of log groups with the SelectionCriteria parameter. If you have multiple account-level index policies with selection criteria, no two of them can use the same or overlapping log group name prefixes. For example, if you have one policy filtered to log groups that start with my-log, you can't have another field index policy filtered to my-logpprod or my-logging.

Transformer policy

A log transformer policy transforms ingested log events into a different format, making them easier for you to process and analyze. You can also transform logs from different sources into standardized formats that contain relevant, source-specific information. After you have created a transformer, CloudWatch Logs performs this transformation at the time of log ingestion. You can then refer to the transformed versions of the logs during operations such as querying with CloudWatch Logs Insights or creating metric filters or subscription filters.

You can also use a transformer to copy metadata from metadata keys into the log events themselves. This metadata can include log group name, log stream name, account ID and Region.

A transformer for a log group is a series of processors, where each processor applies one type of transformation to the log events ingested into this log group. For more information about the available processors to use in a transformer, see Processors that you can use.

Having log events in standardized format enables visibility across your applications for your log analysis, reporting, and alarming needs. CloudWatch Logs provides transformation for common log types with out-of-the-box transformation templates for major AWS log sources such as VPC flow logs, Lambda, and Amazon RDS. You can use pre-built transformation templates or create custom transformation policies.

You can create transformers only for the log groups in the Standard log class.

You can have one account-level transformer policy that applies to all log groups in the account. Or you can create as many as 20 account-level transformer policies that are each scoped to a subset of log groups with the selectionCriteria parameter. If you have multiple account-level transformer policies with selection criteria, no two of them can use the same or overlapping log group name prefixes. For example, if you have one policy filtered to log groups that start with my-log, you can't have another field index policy filtered to my-logpprod or my-logging.

You can also set up a transformer at the log-group level. For more information, see AWS::Logs::Transformer. If there is both a log-group level transformer created with PutTransformer and an account-level transformer that could apply to the same log group, the log group uses only the log-group level transformer. It ignores the account-level transformer.

Syntax

To declare this entity in your AWS CloudFormation template, use the following syntax:

{
  "Type" : "AWS::Logs::AccountPolicy",
  "Properties" : {
      "PolicyDocument" : String,
      "PolicyName" : String,
      "PolicyType" : String,
      "Scope" : String,
      "SelectionCriteria" : String
    }
}

Type: AWS::Logs::AccountPolicy
Properties:
  PolicyDocument: String
  PolicyName: String
  PolicyType: String
  Scope: String
  SelectionCriteria: String

Properties

Return values

Fn::GetAtt

The Fn::GetAtt intrinsic function returns a value for a specified attribute of this type. The following are the available attributes and sample return values.

For more information about using the Fn::GetAtt intrinsic function, see Fn::GetAtt.

Examples

Create an account-level field index policy

The following example creates an account-level field index policy that creates an index on the RequestId and TransactionId fields for log groups with names with the /aws/ prefix.

"IndexingAccountPolicy": {
    "Type": "AWS::Logs::AccountPolicy", 
    "Properties": {
        "PolicyName": "test-fieldindexing-policy",
        "PolicyDocument": {
            "Fn::Sub": "{\"Fields\": [\"RequestId\", \"TransactionId\"]}"
        },
        "SelectionCriteria": {
            "Fn::Sub": "LogGroupNamePrefix=\"/aws/\""
        },                
        "PolicyType": "FIELD_INDEX_POLICY",                
        "Scope": "ALL"
            }    
 }

IndexingAccountPolicy:
  Type: AWS::Logs::AccountPolicy
    Properties:
      PolicyName: "test-fieldindexing-policy"
      PolicyDocument: !Sub "{\"Fields\": [\"RequestId\", \"TransactionId\"]}"
      SelectionCriteria: !Sub "LogGroupNamePrefix = \"/aws/\""
      PolicyType: "FIELD_INDEX_POLICY"
      Scope: "ALL"

Create an account-level data protection policy

The following example creates an account-level data protection policy that finds and masks email addresses in log events. It also sends audit findings to the EXISTING_LOG_GROUP_NAME log group in CloudWatch Logs.

{
    "Resources": {
        "AccountPolicy": {
            "Type": "AWS::Logs::AccountPolicy",
            "Properties": {
                "PolicyName": "TestPolicy",
                "PolicyDocument": "{ \"Name\": \"data-protection-policy\", \"Description\": \"\", \"Version\": \"2021-06-01\", \"Statement\": [ { \"Sid\": \"audit-policy\", \"DataIdentifier\": [ \"arn:aws:dataprotection::aws:data-identifier/EmailAddress\" ], \"Operation\": { \"Audit\": { \"FindingsDestination\": { \"CloudWatchLogs\": { \"LogGroup\": \"EXISTING_LOG_GROUP_NAME\" } } } } }, { \"Sid\": \"redact-policy\", \"DataIdentifier\": [ \"arn:aws:dataprotection::aws:data-identifier/EmailAddress\" ], \"Operation\": { \"Deidentify\": { \"MaskConfig\": {} } } } ] }",
                "PolicyType": "DATA_PROTECTION_POLICY",
                "Scope": "ALL"
            }
        }
    }
}

Resources:
  AccountPolicy:
    Type: AWS::Logs::AccountPolicy
    Properties:
      PolicyName: "TestPolicy"
      PolicyDocument: '{
        "Name": "data-protection-policy",
        "Description": "",
        "Version": "2021-06-01",
        "Statement": [
          {
            "Sid": "audit-policy",
            "DataIdentifier": [
              "arn:aws:dataprotection::aws:data-identifier/EmailAddress"
            ],
            "Operation": {
              "Audit": {
                "FindingsDestination": {
                  "CloudWatchLogs": {
                    "LogGroup": "EXISTING_LOG_GROUP_NAME"
                  }
                }
              }
            }
          },
          {
            "Sid": "redact-policy",
            "DataIdentifier": [
              "arn:aws:dataprotection::aws:data-identifier/EmailAddress"
            ],
            "Operation": {
              "Deidentify": {
                "MaskConfig": {}
              }
            }
          }
        ]
      }'
      PolicyType: "DATA_PROTECTION_POLICY"
      Scope: "ALL"

Create an account-level subscription filter policy

The following example creates an account-level subscription filter policy that forwards the log events matching the FilterPattern from all the log groups in an account to the specified ak Kinesis Data Streams stream. It forwards the log events from all the log groups except the ones that are specified in the SelectionCriteria field.

{
    "Resources": {
        "AccountPolicy": {
            "Type": "AWS::Logs::AccountPolicy",
            "Properties": {
                "PolicyName": "test-subscriptionfilter-policy",
                "PolicyDocument": {
                    "Fn::Sub": "{\"RoleArn\":\"arn:${AWS::Partition}:iam::${AWS::AccountId}:role/MyCWLtoKinesisRole\", \"DestinationArn\":\"arn:${AWS::Partition}:kinesis:${AWS::Region}:${AWS::AccountId}:stream/MyKinesisStream\", \"FilterPattern\": \"Test\", \"Distribution\": \"Random\"}"
                },
                "SelectionCriteria": {
                    "Fn::Sub": "LogGroupName NOT IN [\"MyLogGroup\", \"MyAnotherLogGroup\"]"
                },
                "PolicyType": "SUBSCRIPTION_FILTER_POLICY",
                "Scope": "ALL"
            }
        }
    }
}

Resources:
  AccountPolicy:
    Type: AWS::Logs::AccountPolicy
    Properties:
      PolicyName: test-subscriptionfilter-policy
      PolicyDocument: !Sub "{\"RoleArn\":\"arn:${AWS::Partition}:iam::${AWS::AccountId}:role/MyCWLtoKinesisRole\", \"DestinationArn\":\"arn:${AWS::Partition}:kinesis:${AWS::Region}:${AWS::AccountId}:stream/MyKinesisStream\", \"FilterPattern\": \"Test\", \"Distribution\": \"Random\"}"
      SelectionCriteria: !Sub "LogGroupName NOT IN [\"MyLogGroup\", \"MyAnotherLogGroup\"]"
      PolicyType: "SUBSCRIPTION_FILTER_POLICY"
      Scope: "ALL"