Supports two main uses cases:

• Creates and configures a single private S3 bucket for storing logs from various AWS services, which are nested as bucket prefixes. Logs will expire after a default of 90 days, with option to configure retention value.
• Creates and configures a single private S3 bucket for a single AWS service. Logs will expire after a default of 90 days, with option to configure retention value.

Logging from the following services is supported for both cases as well as in AWS GovCloud:

• Application Load Balancer(ALB)
• Classic Elastic Load Balancer(ELB)
• Network Load Balancer(NLB)
• CloudTrail
• Config
• RedShift
• S3

Usage for a single log bucket storing logs from all services

# Allows all services to log to bucket
module "aws_logs" {
  source         = "trussworks/logs/aws"
  s3_bucket_name = "my-company-aws-logs"
}

Usage for a single log bucket storing logs from a single service (ELB in this case)

module "aws_logs" {
  source         = "trussworks/logs/aws"
  s3_bucket_name = "my-company-aws-logs-elb"
  default_allow  = false
  allow_elb      = true
}

Usage for a single log bucket storing logs from multiple specified services (ALB and ELB in this case)

module "aws_logs" {
  source         = "trussworks/logs/aws"
  s3_bucket_name = "my-company-aws-logs-lb"
  default_allow  = false
  allow_alb      = true
  allow_elb      = true
}

Usage for a single log bucket storing CloudTrail logs from multiple accounts

module "aws_logs" {
  source              = "trussworks/logs/aws"
  s3_bucket_name      = "my-company-aws-logs-cloudtrail"
  default_allow       = false
  allow_cloudtrail    = true
  cloudtrail_accounts = [data.aws_caller_identity.current.account_id, aws_organizations_account.example.id]
}

Usage for a single log bucket storing logs from multiple application load balancers (ALB) and network load balancers (NLB)

module "aws_logs" {
  source            = "trussworks/logs/aws"
  s3_bucket_name    = "my-company-aws-logs-lb"
      default_allow     = false
      allow_alb         = true
      allow_nlb         = true
      alb_logs_prefixes = [
       "alb/hello-world-prod",
       "alb/hello-world-staging",
       "alb/hello-world-experimental",
      ]
      nlb_logs_prefixes = [
       "nlb/hello-world-prod",
       "nlb/hello-world-staging",
       "nlb/hello-world-experimental",
      ]
    }

Requirements

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No modules.

Resources

Inputs

Outputs

Upgrade Paths

Upgrading from 14.x.x to 15.x.x

Version 15.x.x updates the module to account for changes made by AWS in April 2023 to the default security settings of new S3 buckets.

Version 15.x.x of this module adds the following resource and variables. How to use the new variables will depend on your use case.

New resource:

• aws_s3_bucket_ownership_controls.aws_logs

New variables:

• allow_s3
• control_object_ownership
• object_ownership
• s3_bucket_acl
• s3_logs_prefix

Steps for updating existing buckets managed by this module:

• Option 1: Disable ACLs. This module's default values for control_object_ownership, object_ownership, and s3_bucket_acl follow the new AWS recommended best practice. For a new S3 bucket, using those settings will disable S3 access control lists for the bucket and set object ownership to BucketOwnerEnforced. For an existing bucket that is used to store s3 server access logs, the bucket ACL permissions for the S3 log delivery group must be migrated to the bucket policy. The changes must be applied in multiple steps.

Step 1: Update the log bucket policy to grant s3:PutObject permission to the logging service principal (logging.s3.amazonaws.com).

Example:

  statement {
    sid    = "s3-logs-put-object"
    effect = "Allow"
    principals {
      type        = "Service"
      identifiers = ["logging.s3.amazonaws.com"]
    }
    actions   = ["s3:PutObject"]
    resources = ["BUCKET_ARN_PLACEHOLDER/LOGGING_PREFIX_PLACEHOLDER/*"]
  }

Step 2: Change s3_bucket_acl to private.

Step 3: Change object_ownership to BucketOwnerEnforced.

• Option 2: Continue using ACLs. To continue using ACLs, set s3_bucket_acl to "log-delivery-write" and set object_ownership to ObjectWriter or BucketOwnerPreferred.

See Controlling ownership of objects and disabling ACLs for your bucket for further details and migration considerations.