In our experience as AWS administrators, we’ve found Amazon Cognito to be incredibly versatile. It seamlessly handles social media logins, supports multi-factor authentication for enhanced security in financial services, and ensures compliance with regulations like HIPAA for healthcare applications. Educational institutions can effectively use Cognito to manage student and faculty access, while gaming platforms leverage it for player account management across different devices.

One of Cognito’s strengths is its ability to facilitate single sign-on solutions and integrate with existing corporate directories. This feature has been a game-changer for many of our enterprise clients, streamlining user management in complex environments.

However, like any powerful tool, Cognito sometimes requires manual intervention beyond its automated processes. We recently encountered a scenario where we needed to perform some hands-on user management in a Cognito User Pool. This experience highlighted the importance of knowing how to search for users, delete specific accounts, and extract user emails manually.

In this post, we’ll walk you through these essential tasks, sharing insights from our recent real-world scenario. Whether you’re troubleshooting access issues, performing data cleanup, or extracting information for analysis, these skills will prove invaluable in managing your Cognito User Pools effectively.

Remember, while Cognito is a robust service, issues can sometimes arise from the applications using it rather than Cognito itself. Having a solid understanding of manual user management techniques can help you quickly identify and resolve such issues, ensuring the smooth operation of your AWS-powered applications.

The Scenario: Manually Managing Cognito Users in User Pools

This is an oddly specific scenario, but it happened to us not too long ago. We encountered a situation where an application that used Amazon Cognito was causing user trouble. After initial investigation, we discovered the issue was more widespread than initially anticipated. We needed to create a comprehensive user list for further analysis. It’s important to note that the problem was not Cognito, but the application itself.

Our approach involved three key steps:

1. Searching for an Amazon Cognito user

2. Deleting a particular user

3. Generating a list of email addresses associated with users

Searching for a User

Our first task was to locate a user who couldn’t register with the application. The AWS Console is the most efficient tool for one-off cases like this. Here’s a quick guide to search for a user:

1. Log into the AWS Management Console

2. Navigate to “Services” and select “Cognito

3. Click “Manager User Pools”

4. Under “General settings,” select “Users and groups”

5. Choose the search criteria (in this case, Email) from the dropdown menu. Enter the user’s email address in the search field. For this instance, the email has been blurred for privacy. Your search results should be empty if the user hasn’t signed up.

6. Interpret the results. If a user profile appears in the search results, we can conclude that the user is registered.

Deleting a User

As of this blog post, there is no way to delete users directly through the AWS Console, we can do so using the AWS Command Line Interface (CLI). For detailed information on this process, refer to the AWS CLI documentation.

To delete the user (ID 1234-3456-abcd-efgh ) from the example Cognito, (ID us-east-1_2IJKxLMNp), follow these steps:

1. Log into the AWS CLI

2. Run the below command:

aws cognito-idp \
  admin-delete-user \
  --user-pool-id us-east-1_2IJKxLMNp \
  --username 01234-3456-abcd-efgh

3. Check for deletion by searching for the user again in the Cognito console (using the same email as before, which has been removed for privacy). The user should no longer appear in the search results.

Extracting Emails

Extracting emails through the list-users API is easy if you have the AWS CLI set up and know a little jq magic. Here’s a command that will extract all user emails and save them to a file:

aws cognito-idp list-users --user-pool-id us-east-1_2IJKxLMNp \
  | jq -r '.Users[].Attributes[] \
  | select(.Name=="email") \
  | .Value' > emails-prod.txt

And there you have it! You can search that list to see if other users have the same issue.

Troubleshooting Common Issues

Here are some common issues you might encounter and how to resolve them:

• Rate limiting: You might hit API rate limits with bulk operations. Use exponential backoff in your scripts to handle this.
• Permissions: Ensure your IAM user or role has the necessary permissions to perform these operations. CloudTrail can be helpful in identifying these issues.
• Inconsistent data: Sometimes, user data might be inconsistent across different Cognito APIs. Always verify critical operations using multiple methods.

Best Practices

• Always work in a test environment before applying changes to production.
• Use AWS CloudTrail to audit user management operations.
• Implement proper error handling in your scripts to avoid partial updates.

• AWS has no supported way of backing up user pools (they have an out-of-support architecture and there are community projects to do this) so it is best not to mess this up.

Conclusion

Mastering these manual Cognito user management tasks can significantly enhance your ability to maintain and troubleshoot AWS applications that rely on user authentication. While automation is generally preferred for large-scale operations, these hands-on techniques prove invaluable for addressing specific issues or performing one-off tasks.

Remember, with great power comes great responsibility. Always exercise caution when modifying user data, especially in production environments. Always have proper backup procedures and thoroughly test operations in a staging environment before applying them to live systems.

As AWS evolves, stay updated with the latest best practices and tools for managing Cognito User Pools. The methods described here provide a solid foundation but be on the lookout for new features or improved workflows that could make your job easier and more efficient.

By mastering these techniques, you’ll be better equipped to handle user management challenges, ensuring the smooth operation of your AWS-powered applications and maintaining the trust of your users.