MySQL Lambda

A small MySQL UDF library for making AWS Lambda calls from a MySQL database. This adds lambda_sync and lambda_async functions to a regular MySQL database. The purpose of this is to help with migration to or from a managed AWS DB that has these functions natively, allowing for custom code executing directly from MySQL.

You can read more about these functions here: https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/AuroraMySQL.Integrating.Lambda.html.

Usage

lambda_sync

You invoke the lambda_sync function synchronously with the RequestResponse invocation type. The function returns the result of the Lambda invocation in a JSON payload. The function has the following syntax.

`lambda_sync` ( @lambda_function_ARN` , @JSON_payload` )

@lambda_function_ARN (string)

The Amazon Resource Name (ARN) of the Lambda function to invoke.

@JSON_payload (string)

The payload for the invoked Lambda function, in JSON format.

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lambda_async

You invoke the lambda_async function asynchronously with the Event invocation type. The function returns null immediately and the function is executed in the background. The function has the following syntax.

`lambda_async` ( @lambda_function_ARN , @JSON_payload )

@lambda_function_ARN (string)

The Amazon Resource Name (ARN) of the Lambda function to invoke.

@JSON_payload (string)

The payload for the invoked Lambda function, in JSON format.

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Docker

There is a Dockerfile included that when will generate mysql_lambda.so for you with Ubuntu 20.04. Compiling on Ubuntu on 20.10 or higher causes the extension not to work in older versions of Linux due to incompatible versions of glibc.

git clone https://github.com/StirlingMarketingGroup/mysql-lambda.git
cd mysql-lambda
DOCKER_BUILDKIT=1 docker build -o . .
sudo cp mysql_lambda.so /usr/lib/mysql/plugin/mysql_lambda.so # replace plugin dir here if needed

Continue below to see the MySQL commands needed to make the functions work in MySQL.

Dependencies

You will need Golang, which you can get from here https://golang.org/doc/install.

You will also need to install the MySQL dev library:

Debian / Ubuntu

sudo apt update
sudo apt install libmysqlclient-dev

Installing

Know your MySQL plugin directory, which can be found by running this MySQL query:

select @@plugin_dir;

then replace /usr/lib/mysql/plugin below with your MySQL plugin directory.

cd ~ # or wherever you store your git projects
git clone https://github.com/StirlingMarketingGroup/mysql-lambda.git
cd mysql-lambda
go build -buildmode=c-shared -o mysql_lambda.so
sudo cp mysql_lambda.so /usr/lib/mysql/plugin/mysql_lambda.so # replace plugin dir here if needed

Enable the function in MySQL by running these MySQL commands

create function`_lambda_sync`returns string soname'mysql_lambda.so';
create function`lambda_async`returns string soname'mysql_lambda.so';

DROP function IF EXISTS `lambda_sync`;

DELIMITER $$
USE `sterling`$$
CREATE FUNCTION `lambda_sync` (`$arn` varchar (2048), `$payload` json)
RETURNS json
BEGIN
RETURN cast(convert(`_lambda_sync`(`$arn`,`$payload`)using utf8mb4)as json);
END$$

DELIMITER ;