go-lambda

This project is a simple example of using Go with SQLC for SQL generation with Migrations, MySQL as the database, and integrating with AWS Lambda and AWS API Gateway.

Setup

Prerequisites

• Go installed on your system (Installation Guide)
• Database migrations (Migration)
• SQLC installed and running (SQLC Installation Guide)
• AWS account with access to Lambda and API Gateway (AWS Free Tier)

Install SQLC

SQLC is a tool for generating type-safe Go code from SQL queries. Install it using the following command:

sudo snap install sqlc

Create sqlc.yaml:

• Create a sqlc.yaml file in the root directory of your project.
• Configure your SQLC settings in this file. You can refer to the SQLC documentation for more information on configuring sqlc.yaml.

Create schema.sql:

• Create a schema.sql file in the root directory of your project and write your database schema.
• Create a query.sql file in the root directory and write your SQL queries in this file.

Generate Go Code using SQLC

• Generate Go code from SQL queries using SQLC:

sqlc generate

Setup Migrations

curl -L https://github.com/golang-migrate/migrate/releases/download/$version/migrate.$os-$arch.tar.gz | tar xvz

• Create a new migration file.

migrate create -ext sql -dir migrations/ -seq <filename> 

• Revert migrations down to a specific version.

migrate -path migrations -database "mysql://username:password@tcp(localhost:3306)/databasename" -verbose down <version>

• Migrations up to a specific version.

migrate -path migrations -database "mysql://username:password@tcp(localhost:3306)/databasename" -verbose up <version>

• Force Apply a Specific Migration Version

migrate -path migrations -database "mysql://username:password@tcp(localhost:3306)/databasename" -verbose force <version>

AWD Lambda Integartion

Create an Compiled Binary as the Code

set GOOS=linux
set GOARCH=amd64
set CGO_ENABLED=0
go build -o bootstrap main.go
zip  -o lambda-handler.zip bootstrap

Deploying to AWS Lambda

1. Go to AWS Lambda Console:

2. Create a New Function:

• Click on "Create function".
• Choose "Author from scratch".
• Enter a function name of your choice.
• Select "Amazon Linux 2023" as the runtime.

3. Configure Function:

• Under "Function code", select "Upload a .zip file".
• Upload the compiled binary file (main) that you created earlier.
• Set the handler to the name of your main function (e.g., main).

4. Set Environment Variables (if necessary):

• Configure any necessary environment variables for your Lambda function.

5. Create Function:

• Click on "Create function" to create your Lambda function.

Setting up API Gateway

1. Go to API Gateway Console:

2. Create a New REST API:

• Click on "Build".
• Choose "REST API".
• Choose "New API".
• Enter an API name of your choice.

3. Create Resources:

• Click on "Actions" and select "Create Resource".
• Enter a resource name and path (e.g., /).

4. Create Method:

• Select the resource you just created.
• Click on "Actions" and select "Create Method".
• Choose the HTTP method you want to use (e.g., POST, GET).
• Select "Lambda Function" as the integration type.
• Choose the Lambda region and enter the Lambda function name.
• Enable "Use Lambda Proxy Integration".

5. Deploy API:

• Click on "Actions" and select "Deploy API".
• Choose the stage (e.g., "prod").
• Click "Deploy".