S3 Log Destination

Common Fate can send audit log events to an Amazon S3 bucket. You can use this to keep an archive of actions taken within Common Fate, or to build your own reports based on access activity within Common Fate.

Logs are written in batches in JSONL format and can optionally be compressed.

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Prerequisites

To configure a webhook integration you’ll need to use version 2.18 or later of our Terraform Provider.

If you’re running a BYOC (“Bring-Your-Own-Cloud”) deployment of Common Fate in your own AWS account, you’ll need to be on v1.43.1 or later of the common-fate/common-fate-deployment/aws Terraform module.

Additionally, you’ll need to deploy an S3 bucket and an AWS IAM role for Common Fate to assume in order to write events to the S3 bucket. The role must meet the following requirements:

• The role should have a policy allowing the s3:GetBucketLocation action on the bucket, and s3:PutObject on the bucket contents.
• The role must have the tag common-fate-allow-assume-role with value true.
• The role must have a trust relationship allowing the Common Fate AWS account to assume the role. We recommend setting an External ID condition on the trust relationship to match the assume_role_external_id parameter in your Common Fate deployment.

You can use our audit-log-bucket Terraform module as a starting point to provision the required S3 bucket and IAM role:

module "audit-log-bucket" {
  source  = "common-fate/audit-log-bucket/aws"
  version = "1.0.2"
  bucket_name = "<the S3 bucket name>"
  common_fate_aws_account = "<your Common Fate AWS account ID>"
  assume_role_external_id = "<value which matches the 'assume_role_external_id' in your Common Fate deployment>"
  writer_role_name        = "common-fate-audit-log-s3-write-role"
}

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Setting up

You can configure an S3 log destination by adding a Terraform resource similar to the below to your Common Fate application configuration:

resource "commonfate_s3_log_destination" "example" {
  name        = "Example Log Destination"
  bucket_name = "example-bucket-name"
  role_arn    = "arn:aws:iam::123456789012:role/common-fate-audit-log-s3-write-role"
  key_template       = "{{ .Year }}/{{ .Month }}/{{ .Day }}/{{ .Hour }}_{{ .Minute }}_{{ .Second }}_{{ .ID }}"
  filter_for_actions = ["grant.requested", "grant.revoked"]
  compression = "gzip"
  batch_duration_in_minutes = 5
  maximum_batch_size = 5000
}

For details on the available variables in the commonfate_s3_log_destination resource, refer to our Terraform provider documentation.