S3 Bucket Policy Configuration for AWS Config

Data Ingestion
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To support a scalable and secure multi-account AWS Config integration with Observe, AWS recommends delivering all Config data to a centralized S3 bucket. This setup simplifies observability and security management by consolidating logs from all accounts into a single location.

This article outlines how to configure an S3 bucket policy that allows multiple AWS accounts to deliver AWS Config data to a shared bucket monitored by Observe.

Prerequisites

  • A central S3 bucket (e.g., observe-central-config-bucket) in the designated log archive or security tooling account.

  • AWS Config enabled in all source accounts, configured to deliver to the shared bucket.

  • The Observe AWS Collection is deployed and configured to subscribe to this shared bucket.

  • List of source account IDs that will write to the bucket.

Example: S3 Bucket Policy for Shared AWS Config Collection

Update the following example:

  • Replace 111111111111, 222222222222 with the source AWS account IDs

  • Replace observe-central-config-bucket with your S3 bucket name

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "AWSConfigPermissionsCheck",
      "Effect": "Allow",
      "Principal": {
        "Service": "config.amazonaws.com"
      },
      "Action": "s3:GetBucketAcl",
      "Resource": "arn:aws:s3:::observe-central-config-bucket"
    },
    {
      "Sid": "AWSConfigWriteAccessAccount1",
      "Effect": "Allow",
      "Principal": {
        "Service": "config.amazonaws.com"
      },
      "Action": "s3:PutObject",
      "Resource": "arn:aws:s3:::observe-central-config-bucket/AWSLogs/111111111111/Config/*",
      "Condition": {
        "StringEquals": {
          "s3:x-amz-acl": "bucket-owner-full-control"
        }
      }
    },
    {
      "Sid": "AWSConfigWriteAccessAccount2",
      "Effect": "Allow",
      "Principal": {
        "Service": "config.amazonaws.com"
      },
      "Action": "s3:PutObject",
      "Resource": "arn:aws:s3:::observe-central-config-bucket/AWSLogs/222222222222/Config/*",
      "Condition": {
        "StringEquals": {
          "s3:x-amz-acl": "bucket-owner-full-control"
        }
      }
    }
  ]
}

Repeat the PutObject block for each AWS account sending Config data.

Updated Bucket Policy to Allow Observe to Read

Assuming:

  • Your Observe collection is using an IAM role like arn:aws:iam::333333333333:role/observe-collection-role

  • Your bucket is observe-central-config-bucket

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "AWSConfigPermissionsCheck",
      "Effect": "Allow",
      "Principal": {
        "Service": "config.amazonaws.com"
      },
      "Action": "s3:GetBucketAcl",
      "Resource": "arn:aws:s3:::observe-central-config-bucket"
    },
    {
      "Sid": "AWSConfigWriteAccessAccount1",
      "Effect": "Allow",
      "Principal": {
        "Service": "config.amazonaws.com"
      },
      "Action": "s3:PutObject",
      "Resource": "arn:aws:s3:::observe-central-config-bucket/AWSLogs/111111111111/Config/*",
      "Condition": {
        "StringEquals": {
          "s3:x-amz-acl": "bucket-owner-full-control"
        }
      }
    },
    {
      "Sid": "AWSConfigWriteAccessAccount2",
      "Effect": "Allow",
      "Principal": {
        "Service": "config.amazonaws.com"
      },
      "Action": "s3:PutObject",
      "Resource": "arn:aws:s3:::observe-central-config-bucket/AWSLogs/222222222222/Config/*",
      "Condition": {
        "StringEquals": {
          "s3:x-amz-acl": "bucket-owner-full-control"
        }
      }
    },
    {
      "Sid": "ObserveReadAccess",
      "Effect": "Allow",
      "Principal": {
        "AWS": "arn:aws:iam::333333333333:role/observe-collection-role"
      },
      "Action": [
        "s3:GetObject",
        "s3:ListBucket"
      ],
      "Resource": [
        "arn:aws:s3:::observe-central-config-bucket",
        "arn:aws:s3:::observe-central-config-bucket/AWSLogs/*/Config/*"
      ]
    }
  ]
}

Security Tip

  • Only grant read access — no s3:PutObject, s3:DeleteObject.

  • Scope access to the specific prefix (AWSLogs/…/Config/) to avoid Observe accidentally reading unrelated bucket contents.

References