Create a basic S3 replication rule

Part 73 of AWS from Zero. This lesson keeps the scope to one S3 behavior you can verify from the terminal.

What we are learning

A replication rule connects a source bucket, an IAM role trusted by S3, a filter, and a destination bucket ARN.

Before you run it

SOURCE_BUCKET="replace-with-versioned-source"
DEST_BUCKET="replace-with-versioned-destination"
REPLICATION_ROLE_ARN="arn:aws:iam::123456789012:role/S3ReplicationRole"

Create and test the replication IAM role first. Both buckets must have versioning enabled.

Cost note: Replication writes a second copy and may add cross-Region transfer and KMS requests.

The command

cat > replication.json <<EOF
{
  "Role": "$REPLICATION_ROLE_ARN",
  "Rules": [{
    "ID": "ReplicateReports",
    "Status": "Enabled",
    "Priority": 1,
    "DeleteMarkerReplication": {"Status": "Disabled"},
    "Filter": {"Prefix": "reports/"},
    "Destination": {"Bucket": "arn:aws:s3:::$DEST_BUCKET"}
  }]
}
EOF
 
aws s3api put-bucket-replication \
  --bucket "$SOURCE_BUCKET" \
  --replication-configuration file://replication.json

A successful configuration command may return no output. Treat inspection as a separate required step.

Inspect the result

aws s3api get-bucket-replication \
  --bucket "$SOURCE_BUCKET" \
  --query "ReplicationConfiguration.Rules[].{ID:ID,Status:Status,Prefix:Filter.Prefix,Destination:Destination.Bucket}" \
  --output table

Read the returned fields rather than assuming the write succeeded exactly as intended.

One tiny variation

echo "replication test" > replication.txt
aws s3 cp replication.txt "s3://$SOURCE_BUCKET/reports/replication.txt"

Replication is asynchronous. Poll the destination rather than expecting immediate consistency.

Common mistake

A valid-looking configuration can still fail at runtime because of role trust, bucket policy, ownership, KMS, or destination permission errors.

Cleanup

aws s3api delete-bucket-replication --bucket "$SOURCE_BUCKET"
rm replication.json replication.txt

Remove the rule. Delete test object versions from both buckets separately.

Next, we will learn Audit an S3 replication configuration.

Official AWS CLI reference