Enable logging S3 via cloudFormation template?

Question

I am trying to create 2 buckets with 2 different policies.

One bucket, VendorsWGLogs, will be the destination for log output.

The other bucket, VendorsWG, will give GetObject, PutObject, and DeleteObject access to a specified IAM group.

Here is what I have so far:

"Resources": {
    "VendorsWGLogs": {
      "Type": "AWS::S3::Bucket",
      "Properties": {},
    },
    "LogsBucketPolicy": {
      "Type": "AWS::S3::BucketPolicy",
      "Properties": {
        "Bucket": {
          "Ref": "VendorsWGLogs"
        },
        "PolicyDocument": {
          "Version": "2012-10-17",
          "Statement": [
            {
              "Sid": "WeatherGuidance LogBucket permissions",
              "Effect": "Allow",
              "Principal": {
                "AWS" : "arn:aws:s3:::VendorsWG"
              },
              "Action": [
                "s3:GetObject",
                "s3:PutObject",
                "s3:PutObjectAcl"
              ],
              "Resource" : { "Fn::Join" : [
                  "", [ "arn:aws:s3:::", { "Ref" : "VendorsWGLogs" } , "/*" ]
               ]}
            }
          ]
        }
      }
    },
    "VendorsWG": {
      "Type": "AWS::S3::Bucket",
      "Properties": {
        "LoggingConfiguration": {
          "DestinationBucketName": {"Ref" : "VendorsWGLogs"},
          "LogFilePrefix": "testing-logs"
        }
      },
      "Metadata": {
        "AWS::CloudFormation::Designer": {
          "id": "a1169860-d743-406e-a3e5-e12831826439"
        },
      }
    },
    "S3BP4TNQZ": {
      "Type": "AWS::S3::BucketPolicy",
      "Properties": {
        "Bucket": {
          "Ref": "VendorsWG"
        },
        "PolicyDocument": {
          "Version": "2012-10-17",
          "Statement": [
            {
              "Sid": "WeatherGuidance Object permissions",
              "Effect": "Allow",
              "Principal": {
                "AWS" : "arn:aws:iam::someUserGroup"
              },
              "Action": [
                "s3:GetObject",
                "s3:PutObject",
                "s3:DeleteObject"
              ],
              "Resource" : { "Fn::Join" : [
                  "", [ "arn:aws:s3:::", { "Ref" : "VendorsWG" } , "/*" ]
               ]}
            },
            {
              "Sid": "WeatherGuidance ListBucket",
              "Effect": "Allow",
              "Principal": {
                "AWS" : "arn:aws:iam::someUserGroup"
              },
              "Action": "s3:ListBucket",
              "Resource" : { "Fn::Join" : [
                  "", [ "arn:aws:s3:::", { "Ref" : "VendorsWG" } ]
               ]},
              "Condition": {
                "StringLike": {
                  "s3:prefix": "weatherguidance*"
                }
              }
            }
          ]
        }
      }
    }
  }

When I try to create a stack, I get this error

Event Log output:

Type:

AWS::S3::Bucket

Logical ID:

VendorsWG   

Status reason:

You must give the log-delivery group WRITE and READ_ACP permissions to the target bucket

I thought that specifying the target bucket's policy's principal as VendorsWGLogs would fix this, and now I am out of ideas.

What am I doing wrong? What can I do to get logging enabled? Thanks

Answer 1

Needed to put this under the log bucket's properties

Properties: {
      AccessControl: "LogDeliveryWrite"
}

Answer 2

I think your problem is two fold:

1. There is no s3:ListBucket in the actions therefore the contents of the bucket can not be read

2. Actions on s3 buckets are run at a bucket (VendorsWGLogs) and contents (VendorsWGLogs/*) level and you therefore need to list both of them under resources. The resulting policy should read

   "Resource": [ "arn:aws:s3:::VendorsWGLogs", "arn:aws:s3:::VendorsWGLogs/*" ]