Using the Amazon Redshift management interfaces for provisioned clusters - Amazon Redshift
Signing an HTTP requestSetting up the Amazon Redshift CLI

Using the Amazon Redshift management interfaces for provisioned clusters

Note

This topic focuses on Amazon Redshift management interfaces for provisioned clusters. There are similar management interfaces for Amazon Redshift Serverless and Amazon Redshift Data API.

Amazon Redshift supports several management interfaces that you can use to create, manage, and delete Amazon Redshift clusters: the AWS SDKs, the AWS Command Line Interface (AWS CLI), and the Amazon Redshift management API.

The Amazon Redshift API – You can call this Amazon Redshift management API by submitting a request. Requests are HTTP or HTTPS requests that use the HTTP verbs GET or POST with a parameter named Action. Calling the Amazon Redshift API is the most direct way to access the Amazon Redshift service. However, it requires that your application handle low-level details such as error handling and generating a hash to sign the request.

AWS SDKs – You can use the AWS SDKs to perform Amazon Redshift cluster-related operations. Several of the SDK libraries wrap the underlying Amazon Redshift API. They integrate the API functionality into the specific programming language and handle many of the low-level details, such as calculating signatures, handling request retries, and error handling. Calling the wrapper functions in the SDK libraries can greatly simplify the process of writing an application to manage an Amazon Redshift cluster.

  • Amazon Redshift is supported by the AWS SDKs for Java, .NET, PHP, Python, Ruby, and Node.js. The wrapper functions for Amazon Redshift are documented in the reference manual for each SDK. For a list of the AWS SDKs and links to their documentation, see Tools for Amazon Web Services .

  • This guide provides examples of working with Amazon Redshift using the Java SDK. For more general AWS SDK code examples, see Code examples for Amazon Redshift using AWS SDKs.

AWS CLI – The CLI provides a set of command line tools that you can use to manage AWS services from Windows, Mac, and Linux computers. The AWS CLI includes commands based on the Amazon Redshift API actions.

Signing an HTTP request

Amazon Redshift requires that every request you send to the management API be authenticated with a signature. This topic explains how to sign your requests.

If you are using one of the AWS Software Development Kits (SDKs) or the AWS Command Line Interface, request signing is handled automatically, and you can skip this section. For more information about using AWS SDKs, see Using the Amazon Redshift management interfaces for provisioned clusters. For more information about using the Amazon Redshift Command Line Interface, go to Amazon Redshift command line reference.

To sign a request, you calculate a digital signature by using a cryptographic hash function. A cryptographic hash is a function that returns a unique hash value that is based on the input. The input to the hash function includes the text of your request and your secret access key that you can get from temporary credentials. The hash function returns a hash value that you include in the request as your signature. The signature is part of the Authorization header of your request.

Note

Users need programmatic access if they want to interact with AWS outside of the AWS Management Console. The way to grant programmatic access depends on the type of user that's accessing AWS.

To grant users programmatic access, choose one of the following options.

Which user needs programmatic access? To By

Workforce identity

(Users managed in IAM Identity Center)

 Use temporary credentials to sign programmatic requests to the AWS CLI, AWS SDKs, or AWS APIs.

Following the instructions for the interface that you want to use.
IAM Use temporary credentials to sign programmatic requests to the AWS CLI, AWS SDKs, or AWS APIs. Following the instructions in Using temporary credentials with AWS resources in the IAM User Guide.
IAM

(Not recommended)

Use long-term credentials to sign programmatic requests to the AWS CLI, AWS SDKs, or AWS APIs.

Following the instructions for the interface that you want to use.

After Amazon Redshift receives your request, it recalculates the signature by using the same hash function and input that you used to sign the request. If the resulting signature matches the signature in the request, Amazon Redshift processes the request; otherwise, the request is rejected.

Amazon Redshift supports authentication using AWS signature version 4. The process for calculating a signature is composed of three tasks. These tasks are illustrated in the example that follows.

  • Task 1: Create a canonical request

    Rearrange your HTTP request into a canonical form. Using a canonical form is necessary because Amazon Redshift uses the same canonical form to calculate the signature it compares with the one you sent.

  • Task 2: Create a string to sign

    Create a string that you will use as one of the input values to your cryptographic hash function. The string, called the string to sign, is a concatenation of the name of the hash algorithm, the request date, a credential scope string, and the canonicalized request from the previous task. The credential scope string itself is a concatenation of date, region, and service information.

  • Task 3: Calculate a signature

    Calculate a signature for your request by using a cryptographic hash function that accepts two input strings, your string to sign and a derived key. The derived key is calculated by starting with your secret access key and using the credential scope string to create a series of hash-based message authentication codes (HMAC-SHA256).

Example signature calculation

The following example walks you through the details of creating a signature for CreateCluster request. You can use this example as a reference to check your own signature calculation method. Other reference calculations are included in the Request signature examples section of the IAM User Guide.

You can use a GET or POST request to send requests to Amazon Redshift. The difference between the two is that for the GET request your parameters are sent as query string parameters. For the POST request they are included in the body of the request. The example below shows a POST request.

The example assumes the following:

  • The time stamp of the request is Fri, 07 Dec 2012 00:00:00 GMT.

  • The endpoint is US East (Northern Virginia) Region, us-east-1.

The general request syntax is:

           

            

             
            

           
https://redshift.us-east-1.amazonaws.com/
   ?Action=CreateCluster
   &ClusterIdentifier=examplecluster
   &MasterUsername=masteruser
   &MasterUserPassword=12345678Aa
   &NumberOfNode=2
   &NodeType=dc2.large
   &Version=2012-12-01
   &x-amz-algorithm=AWS4-HMAC-SHA256
   &x-amz-credential=AKIAIOSFODNN7EXAMPLE/20121207/us-east-1/redshift/aws4_request
   &x-amz-date=20121207T000000Z
   &x-amz-signedheaders=content-type;host;x-amz-date

The canonical form of the request calculated for Task 1: Create a Canonical Request is:

           

            

             
            

           
POST
/

content-type:application/x-www-form-urlencoded; charset=utf-8
host:redshift.us-east-1.amazonaws.com
x-amz-date:20121207T000000Z

content-type;host;x-amz-date
55141b5d2aff6042ccd9d2af808fdf95ac78255e25b823d2dbd720226de1625d

The last line of the canonical request is the hash of the request body. The third line in the canonical request is empty because there are no query parameters for this API.

The string to sign for Task 2: Create a String to Sign is:

           

            

             
            

           
AWS4-HMAC-SHA256
20121207T000000Z
20121207/us-east-1/redshift/aws4_request
06b6bef4f4f060a5558b60c627cc6c5b5b5a959b9902b5ac2187be80cbac0714

The first line of the string to sign is the algorithm, the second line is the time stamp, the third line is the credential scope, and the last line is a hash of the canonical request from Task 1: Create a Canonical Request. The service name to use in the credential scope is redshift.

For Task 3: Calculate a Signature, the derived key can be represented as:

           

            

             
            

           
derived key = HMAC(HMAC(HMAC(HMAC("AWS4" + YourSecretAccessKey,"20121207"),"us-east-1"),"redshift"),"aws4_request")

The derived key is calculated as series of hash functions. Starting from the inner HMAC statement in the formula above, you concatenate the phrase AWS4 with your secret access key and use this as the key to hash the data "us-east-1". The result of this hash becomes the key for the next hash function.

After you calculate the derived key, you use it in a hash function that accepts two input strings, your string to sign and the derived key. For example, if you use the secret access key wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY and the string to sign given earlier, then the calculated signature is as follows:

           

            

             
            

           
9a6b557aa9f38dea83d9215d8f0eae54100877f3e0735d38498d7ae489117920

The final step is to construct the Authorization header. For the demonstration access key AKIAIOSFODNN7EXAMPLE, the header (with line breaks added for readability) is:

           

            

             
            

           
Authorization: AWS4-HMAC-SHA256 Credential=AKIAIOSFODNN7EXAMPLE/20121207/us-east-1/redshift/aws4_request, 
SignedHeaders=content-type;host;x-amz-date, 
Signature=9a6b557aa9f38dea83d9215d8f0eae54100877f3e0735d38498d7ae489117920

Setting up the Amazon Redshift CLI

This section explains how to set up and run the AWS CLI command line tools for use in managing Amazon Redshift. The Amazon Redshift command line tools run on the AWS Command Line Interface (AWS CLI), which in turn uses Python (https://www.python.org/ ). The AWS CLI can be run on any operating system that supports Python.

Installation instructions

To begin using the Amazon Redshift command line tools, you first set up the AWS CLI, and then you add configuration files that define the Amazon Redshift CLI options.

If you have already installed and configured the AWS CLI for another AWS service, you can skip this procedure.

To install the AWS Command Line Interface

  1. Go to Install or update to the latest version of the AWS CLI, and then follow the instructions for installing the AWS CLI.

    For CLI access, you need an access key ID and a secret access key. Use temporary credentials instead of long-term access keys when possible. Temporary credentials include an access key ID, a secret access key, and a security token that indicates when the credentials expire. For more information, see Using temporary credentials with AWS resources in the IAM User Guide.

  2. Create a file containing configuration information such as your access keys, default region, and command output format. Then set the AWS_CONFIG_FILE environment variable to reference that file. For detailed instructions, go to Configuring the AWS command line interface in the AWS Command Line Interface User Guide.

  3. Run a test command to confirm that the AWS CLI interface is working. For example, the following command should display help information for the AWS CLI:

                  
    
               
    
                
               
    
              
    aws help

    The following command should display help information for Amazon Redshift:

                  
    
               
    
                
               
    
              
    aws redshift help

For reference material on the Amazon Redshift CLI commands, go to Amazon Redshift in the AWS CLI Reference.