AmazonServiceException: User is not authorized to perform: dynamodb:DescribeTable Status Code: 400; Error Code: AccessDeniedException
Understanding the Error
This error message indicates that the user account attempting to access a DynamoDB table lacks the necessary permissions to execute the ‘DescribeTable’ operation. This operation is essential for retrieving detailed information about a table, including its schema, provisioned throughput, and other settings.
Causes
* **Missing IAM Policy:** The IAM policy attached to the user or role does not include the ‘dynamodb:DescribeTable’ action.
* **Insufficient Permissions:** The IAM policy might allow access to DynamoDB but not specifically grant permission for ‘DescribeTable’.
* **Incorrect Resource ARN:** The IAM policy might specify the wrong ARN (Amazon Resource Name) for the DynamoDB table.
* **Incorrect Region:** The DynamoDB operation is being performed in a region different from where the table resides.
* **Table Does Not Exist:** The table specified in the request does not exist.
Troubleshooting Steps
1. Verify IAM Policy
* **Locate the IAM Policy:** Access the IAM console and find the policy attached to the user or role.
* **Examine DynamoDB Permissions:** Check if the policy includes the ‘dynamodb:DescribeTable’ action.
* **Ensure Correct Resource ARN:** Verify that the policy uses the correct ARN for the DynamoDB table.
* **Review Region Specifications:** Ensure that the IAM policy is scoped to the correct region.
2. Review DynamoDB Access
* **Table Existence:** Verify that the DynamoDB table exists.
* **Permissions Check:** Using the DynamoDB console or AWS CLI, attempt to describe the table using a different account or user with known permissions.
3. Update IAM Policy
* **Add ‘dynamodb:DescribeTable’ Action:** Include the ‘dynamodb:DescribeTable’ action in the IAM policy attached to the user or role.
* **Specify Resource ARN:** Ensure that the policy specifies the correct ARN for the DynamoDB table.
Example IAM Policy
“`
{
“Version”: “2012-10-17”,
“Statement”: [
{
“Effect”: “Allow”,
“Action”: [
“dynamodb:DescribeTable”
],
“Resource”: “arn:aws:dynamodb:us-east-1:123456789012:table/my-table”
}
]
}
“`
Example Usage
**Using AWS CLI:**
“`
aws dynamodb describe-table –table-name my-table
“`
**Expected Output:**
“`
{
“Table”: {
“TableName”: “my-table”,
“AttributeDefinitions”: [
{
“AttributeName”: “customerID”,
“AttributeType”: “S”
}
],
“KeySchema”: [
{
“AttributeName”: “customerID”,
“KeyType”: “HASH”
}
],
“ProvisionedThroughput”: {
“NumberOfReadsPerSecond”: 5,
“NumberOfWritesPerSecond”: 5
},
…
}
}
“`
Note:
Replace ‘my-table’ with the actual table name and ‘us-east-1’ with the region where the DynamoDB table resides.
**If you still encounter this error after troubleshooting, consult the official AWS documentation and error logs for further assistance.**