Transfer file from S3 to Remote SFTP server

To transfer a file from an S3 bucket to a remote SFTP server with PGP encryption, you can indeed use AWS Transfer Family's SFTP connector. This approach offers a managed, secure solution for file transfers between AWS and external SFTP servers.

Here's a recommended workflow:

1. PGP Encryption: First, encrypt the file in S3 using PGP. This can be done using a Lambda function triggered by an S3 event when a new file is uploaded.

2. SFTP Connector: Create an SFTP connector in AWS Transfer Family to establish a connection with the remote SFTP server.

3. File Transfer: Use the StartFileTransfer API operation to initiate the transfer of the encrypted file from S3 to the remote SFTP server via the SFTP connector.

4. Error Handling: Implement retry logic for failed transfers and set up CloudWatch alarms to monitor the transfer process.

5. Status Checking: AWS Transfer Family automatically emits status events to EventBridge after every file transfer operation. You can use these events to track the status of your transfers.

Regarding the use of Managed Workflows, while AWS Transfer Family provides SFTP connectors, it doesn't currently offer a native "Managed Workflow" feature that directly integrates with these connectors. However, you can create a custom workflow using AWS Step Functions or Lambda functions to orchestrate the process, including calling the SFTP connector.

For best practices and error handling:

1. Store SFTP credentials securely in AWS Secrets Manager.
2. Use IAM roles to manage permissions for S3 access and Secrets Manager.
3. Implement logging with CloudWatch for monitoring and troubleshooting.
4. Set up CloudWatch alarms for failed transfers or other critical events.
5. Use EventBridge rules to trigger notifications or actions based on transfer status events.

To check the status of file transfers:

1. Configure your SFTP connector to emit events to EventBridge.
2. Create EventBridge rules to filter for successful and failed transfer events.
3. Set up Lambda functions or other AWS services to process these events and update your status tracking system (e.g., DynamoDB table, S3 object metadata).

This approach allows for a scalable, serverless architecture that can handle file transfers efficiently while providing robust error handling and status tracking capabilities.
Sources
AWS Transfer Family SFTP connectors - AWS Transfer Family
Setting up and using SFTP connectors - AWS Transfer Family
Serverless Upload a file from S3 Bucket to remote SFTP Server - Common Scenario | AWS re:Post

Hi! The architecture in this workshop shows how to design such a flow, including PGP encryption and transfer status checking - https://catalog.us-east-1.prod.workshops.aws/workshops/e55c90e0-bbb0-47e1-be83-6bafa3a59a8a/en-US/60-module-2

Managed Workflows are currently only triggered for file uploads over your server endpoints. You can use the custom lambda step in your workflow to call the connector APIs as well, but note that such a workflow will still be triggered only upon a file upload event on your servers. Would be curious to learn more about your use-cases so we can recommend appropriate solutions - suggest you to reach out to the Transfer Family service team via AWS support or your account team.