AWS Rust Lamdba function with DynamoDB

By: Dingkun Yang

Posted: March 01, 2024

Project Link: Click this link

Description

This is a simple example of a Rust Lambda function that uses DynamoDB. The function will be triggered by an API Gateway event and will store the request body in a DynamoDB table.

This project idea is motivated by the requirements of another project, Wastewater Treatment Plant, where there's a necessity to store inference data generated by a machine learning model in the cloud. The objective is to create a system that automatically triggers a function responsible for storing the data and comparing the predictions with the ground truth. Subsequently, the system adds a boolean value (true or false) to the "correct" column in the DynamoDB table. This process is carried out in addition to handling JSON payloads provided by the user or API Gateway.

The following is an example of the request body that the function expects:

{
    "wwtp": "Wwtp_name",
    "ground_truth": "Yes or No",
    "prediction": "Wes or No",
}

The following is an example of the table in Excel format: Example

Flowchart of the function

Prerequisites and Dependencies

Code is developed with Rust
- cargo-lambda
Function deployed to AWS Lambda
- Upload the function to AWS Lambda
  - using .zip file
  - OR using cargo lambda deploy
Using AWS CLI to manage AWS services
- Configure the AWS CLI with aws configure
- OR set the environment variables
Managing the function's permissions with AWS IAM
- Create a user or assign the role with the following permissions:
  - AWSLambdaFullAccess
  - AmazonDynamoDBFullAccess
  - AWSLambdaDynamoDBExecutionRole
- Set the user's access key and secret key
  - using aws configure
  - or setting the environment variables AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, and AWS_DEFAULT_REGION with
```
export AWS_ACCESS_KEY_ID=your_access_key
export AWS_SECRET_ACCESS_KEY=your_secret_key
export AWS_DEFAULT_REGION=your_region
```
Storing information to AWS DynamoDB table
- Create a table with the name matching the TABLE_NAME in the main.rs file
- The table should have a primary key

Using AWS API Gateway to trigger the function and handle requests for inputing data to the DynamoDB table

Build and Deploy

Build the function

cargo build --release

Create a .zip file

cargo lambda build --release

Deploy the function to AWS Lambda

cargo lambda deploy

Test the function

Trigger the function using the AWS Lambda console
OR use the AWS API Gateway to trigger the function

Screenshots

AWS Lambda functionality
AWS DynamoDB table

Even though we did not specify the "correct" column in the request body, the function automatically adds the "correct" column with a boolean value (true or false) to the DynamoDB table. This is a feature of the function that is shown in the screenshot.

License

This project is licensed under the MIT License - see the LICENSE file for details.