Troubleshooting Guide: Fixing Execution Failed Due to Configuration Error - Invalid Permissions on Your Lambda Function

Learn how to resolve the "Execution failed due to configuration error" issue caused by invalid permissions on your AWS Lambda function. This step-by-step guide will help you identify the problem, update the required permissions, and test your Lambda function successfully.

Table of Contents

• Identifying the Problem
• Updating the Execution Role
• Testing the Lambda Function
• FAQ
• What are AWS Lambda permissions?
• What is an Execution Role?
• How can I create a new Execution Role?
• How do I attach an AWS managed policy to my Execution Role?
• How can I create a custom policy for my Execution Role?

Identifying the Problem

The error message "Execution failed due to configuration error: Invalid permissions on Lambda function" usually occurs when the Execution Role does not have the necessary permissions for your Lambda function to access other AWS services or resources.

To identify the problem, follow these steps:

1. Open the AWS Lambda Console.
2. Select your Lambda function from the list.
3. Check the "Execution Role" section in the "Function code" tab.

[AWS Lambda Console](https://console.aws.amazon.com/lambda/)

Updating the Execution Role

To update the Execution Role, you need to add the necessary permissions that your Lambda function requires to access other AWS services.

1. Open the AWS IAM Console.
2. In the left navigation pane, click on "Roles."
3. Search for your Lambda function's Execution Role in the list.
4. Click on the role's name to view its details.
5. In the "Permissions" tab, click on "Attach policies" to add the required permissions.

[AWS IAM Console](https://console.aws.amazon.com/iam/)

Here, you can either attach an AWS managed policy or create a custom policy for your Execution Role.

Testing the Lambda Function

After updating the Execution Role with the required permissions, follow these steps to test your Lambda function:

1. Go back to the AWS Lambda Console.
2. Select your Lambda function from the list.
3. Click on the "Test" button at the top-right corner.
4. Configure a test event and click on "Create."
5. Click on the "Test" button again to execute your Lambda function with the test event.

[AWS Lambda Console](https://console.aws.amazon.com/lambda/)

If your Lambda function executes successfully, the issue is resolved. If not, review the Execution Role's permissions and ensure they are correctly configured.

FAQ

What are AWS Lambda permissions?

AWS Lambda permissions define what actions your Lambda function can perform and which resources it can access within your AWS account. Permissions are managed through IAM policies that are attached to the Lambda function's Execution Role.

[AWS Lambda Permissions](https://docs.aws.amazon.com/lambda/latest/dg/lambda-permissions.html)

What is an Execution Role?

An Execution Role is an IAM role that grants your Lambda function permissions to access AWS services and resources. When you create a Lambda function, you need to specify an Execution Role that the function will assume to access the required resources.

[AWS Lambda Execution Role](https://docs.aws.amazon.com/lambda/latest/dg/lambda-intro-execution-role.html)

How can I create a new Execution Role?

To create a new Execution Role:

1. Open the AWS IAM Console.
2. In the left navigation pane, click on "Roles."
3. Click on "Create role."
4. Select "AWS service" as the trusted entity type and choose "Lambda" as the use case.
5. Click on "Next: Permissions" and attach the required policies.
6. Click on "Next: Tags" to add optional tags.
7. Click on "Next: Review" and provide a name and description for the role.
8. Click on "Create role" to finish the process.

[Creating a Role to Delegate Permissions to an AWS Service](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_create_for-service.html)

How do I attach an AWS managed policy to my Execution Role?

To attach an AWS managed policy to your Execution Role:

1. Open the AWS IAM Console.
2. In the left navigation pane, click on "Roles."
3. Search for your Execution Role in the list and click on its name.
4. In the "Permissions" tab, click on "Attach policies."
5. Search and select the desired AWS managed policy.
6. Click on "Attach policy" to confirm.

[Attaching a Policy](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies_manage-attach.html#add-policies-console)

How can I create a custom policy for my Execution Role?

To create a custom policy for your Execution Role:

1. Open the AWS IAM Console.
2. In the left navigation pane, click on "Policies."
3. Click on "Create policy."
4. Use the "Visual editor" or "JSON" tab to define the policy's permissions.
5. Click on "Review policy" and provide a name and description for the policy.
6. Click on "Create policy" to finish the process.
7. Go to the "Roles" section, search for your Execution Role, and attach the newly created policy.

[Creating IAM Policies](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies_create.html)