AWS::Logs::LogGroup - AWS CloudFormation
SyntaxPropertiesReturn valuesExamples

AWS::Logs::LogGroup

The AWS::Logs::LogGroup resource specifies a log group. A log group defines common properties for log streams, such as their retention and access control rules. Each log stream must belong to one log group.

You can create up to 1,000,000 log groups per Region per account. You must use the following guidelines when naming a log group:

  • Log group names must be unique within a Region for an AWS account.

  • Log group names can be between 1 and 512 characters long.

  • Log group names consist of the following characters: a-z, A-Z, 0-9, '_' (underscore), '-' (hyphen), '/' (forward slash), and '.' (period).

Syntax

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

JSON

{
  "Type" : "AWS::Logs::LogGroup",
  "Properties" : {
      "DataProtectionPolicy" : Json,
      "FieldIndexPolicies" : [ {Key: Value, ...}, ... ],
      "KmsKeyId" : String,
      "LogGroupClass" : String,
      "LogGroupName" : String,
      "RetentionInDays" : Integer,
      "Tags" : [ Tag, ... ]
    }
}

YAML

Type: AWS::Logs::LogGroup
Properties:
  DataProtectionPolicy: Json
  FieldIndexPolicies: 
    - 
    Key: Value
  KmsKeyId: String
  LogGroupClass: String
  LogGroupName: String
  RetentionInDays: Integer
  Tags: 
    - Tag

Properties

DataProtectionPolicy

Creates a data protection policy and assigns it to the log group. A data protection policy can help safeguard sensitive data that's ingested by the log group by auditing and masking the sensitive log data. When a user who does not have permission to view masked data views a log event that includes masked data, the sensitive data is replaced by asterisks.

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

Required: No

Type: Json

Update requires: No interruption

FieldIndexPolicies

Creates or updates a field index policy for the specified log group. Only log groups in the Standard log class support field index policies. For more information about log classes, see Log classes.

You can use field index policies to create field indexes on fields found in log events in the log group. Creating field indexes lowers the costs for CloudWatch Logs Insights queries that reference those field indexes, 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 and fields that have high cardinality of values Common examples of indexes include request ID, session ID, userID, and instance IDs. For more information, see Create field indexes to improve query performance and reduce costs.

Currently, this array supports only one field index policy object.

Required: No

Type: Array of Object

Update requires: No interruption

KmsKeyId

The Amazon Resource Name (ARN) of the AWS KMS key to use when encrypting log data.

To associate an AWS KMS key with the log group, specify the ARN of that KMS key here. If you do so, ingested data is encrypted using this key. This association is stored as long as the data encrypted with the KMS key is still within CloudWatch Logs. This enables CloudWatch Logs to decrypt this data whenever it is requested.

If you attempt to associate a KMS key with the log group but the KMS key doesn't exist or is deactivated, you will receive an InvalidParameterException error.

Log group data is always encrypted in CloudWatch Logs. If you omit this key, the encryption does not use AWS KMS. For more information, see Encrypt log data in CloudWatch Logs using AWS Key Management Service

Required: No

Type: String

Pattern: ^arn:[a-z0-9-]+:kms:[a-z0-9-]+:\d{12}:(key|alias)/.+\Z

Maximum: 256

Update requires: No interruption

LogGroupClass

Specifies the log group class for this log group. There are two classes:

  • The Standard log class supports all CloudWatch Logs features.

  • The Infrequent Access log class supports a subset of CloudWatch Logs features and incurs lower costs.

For details about the features supported by each class, see Log classes

Required: No

Type: String

Allowed values: STANDARD | INFREQUENT_ACCESS

Update requires: Updates are not supported.

LogGroupName

The name of the log group. If you don't specify a name, AWS CloudFormation generates a unique ID for the log group.

Required: No

Type: String

Pattern: ^[.\-_/#A-Za-z0-9]{1,512}\Z

Minimum: 1

Maximum: 512

Update requires: Replacement

RetentionInDays

The number of days to retain the log events in the specified log group. Possible values are: 1, 3, 5, 7, 14, 30, 60, 90, 120, 150, 180, 365, 400, 545, 731, 1096, 1827, 2192, 2557, 2922, 3288, and 3653.

To set a log group so that its log events do not expire, use DeleteRetentionPolicy.

Required: No

Type: Integer

Allowed values: 1 | 3 | 5 | 7 | 14 | 30 | 60 | 90 | 120 | 150 | 180 | 365 | 400 | 545 | 731 | 1096 | 1827 | 2192 | 2557 | 2922 | 3288 | 3653

Update requires: No interruption

Tags

An array of key-value pairs to apply to the log group.

For more information, see Tag.

Required: No

Type: Array of Tag

Update requires: No interruption

Return values

Ref

When you pass the logical ID of this resource to the intrinsic Ref function, Ref returns the resource name.

For more information about using the Ref function, see Ref.

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.

Arn

The ARN of the log group, such as arn:aws:logs:us-west-1:123456789012:log-group:/mystack-testgroup-12ABC1AB12A1:*

Examples

Create a log group

The following example creates a log group that retains events for seven days.

JSON

"myLogGroup": {
    "Type": "AWS::Logs::LogGroup",
    "Properties": {
        "RetentionInDays": 7
    }
}

YAML

myLogGroup: 
  Type: AWS::Logs::LogGroup
  Properties: 
    RetentionInDays: 7

Create a log group with a data protection policy

The following example creates a log group that uses a data protection policy to mask email addresses, and send audit findings to CloudWatch Logs, Firehose, and Amazon S3.

JSON

"TestLogGroupDescription": {
  "Type": "AWS::Logs::LogGroup",
  "Properties": {
      "LogGroupName": "my-log-group",
      "DataProtectionPolicy": {
          "Name": "data-protection-policy",
          "Description": "test description",
          "Version": "2021-06-01",
          "Statement": [{
                  "Sid": "audit-policy test",
                  "DataIdentifier": [
                      "arn:aws:dataprotection::aws:data-identifier/EmailAddress",
                      "arn:aws:dataprotection::aws:data-identifier/DriversLicense-US"
                  ],
                  "Operation": {
                      "Audit": {
                          "FindingsDestination": {
                              "CloudWatchLogs": {
                                  "LogGroup": "EXISTING_LOG_GROUP_IN_YOUR_ACCOUNT"
                              },
                              "Firehose": {
                                  "DeliveryStream": "EXISTING_STREAM_IN_YOUR_ACCOUNT"
                              },
                              "S3": {
                                  "Bucket": "EXISTING_BUCKET"
                              }
                          }
                      }
                  }
              },
              {
                  "Sid": "redact-policy",
                  "DataIdentifier": [
                      "arn:aws:dataprotection::aws:data-identifier/EmailAddress",
                      "arn:aws:dataprotection::aws:data-identifier/DriversLicense-US"
                  ],
                  "Operation": {
                      "Deidentify": {
                          "MaskConfig": {}
                      }
                  }
              }
          ]
      }
  }
}

YAML

TestLogGroupDescription:
  Type: AWS::Logs::LogGroup
  Properties:
    LogGroupName: my-log-group
    DataProtectionPolicy:
      Name: data-protection-policy
      Description: test description
      Version: '2021-06-01'
      Statement:
      - Sid: audit-policy test
        DataIdentifier:
        - arn:aws:dataprotection::aws:data-identifier/EmailAddress
        - arn:aws:dataprotection::aws:data-identifier/DriversLicense-US
        Operation:
          Audit:
            FindingsDestination:
              CloudWatchLogs:
                LogGroup: EXISTING_LOG_GROUP_IN_YOUR_ACCOUNT
              Firehose:
                DeliveryStream: EXISTING_STREAM_IN_YOUR_ACCOUNT
              S3:
                Bucket: EXISTING_BUCKET
      - Sid: redact-policy
        DataIdentifier:
        - arn:aws:dataprotection::aws:data-identifier/EmailAddress
        - arn:aws:dataprotection::aws:data-identifier/DriversLicense-US
        Operation:
          Deidentify:
            MaskConfig: {}

Create a log group with a field index policy

The following example creates a log group that uses a field index policy to index the RequestId and TransactionId fields in log events.

JSON

"TestFieldIndexingLogGroup": {
    "Type": "AWS::Logs::LogGroup", 
    "Properties": {
        "LogGroupName": "my-log-group",
        "FieldIndexPolicies": [{
            "Fields": [
                "RequestId",
                "TransactionId"
            ]
        }]
    }
}

YAML

TestFieldIndexingLogGroup:
  Type: AWS::Logs::LogGroup
  Properties:
    LogGroupName: my-log-group
    FieldIndexPolicies:
        - Fields:
            - RequestId
            - TransactionId