Table of Contents

The Error

When working with Terraform, you may encounter this error:

Error: Creating CloudWatch Log Group: ResourceAlreadyExistsException

This error can block your entire workflow. Let’s understand why it happens and how to fix it.

What Causes This Error

A CloudWatch Log Group with the same name already exists, often left over from a previous Lambda or ECS deployment.

How to Fix It

Solution 1

Import the existing log group: terraform import aws_cloudwatch_log_group.example /aws/lambda/my-function

Solution 2

Delete the orphaned log group manually if it contains no important logs.

Solution 3

Use a unique name pattern: /aws/lambda/${var.function_name}-${var.env}

Solution 4

For Lambda: set skip_destroy = true on the log group to prevent orphaning.

Prevention Tips

  • Always run terraform validate before terraform plan
  • Use terraform fmt to keep configuration clean and readable
  • Pin provider versions to avoid unexpected schema changes
  • Review plan output carefully before applying

Learn More

Conclusion

This error is common but straightforward to fix. The key is understanding the root cause and applying the correct solution for your specific situation. Following the prevention tips above will help you avoid this error in future projects.