This project contains source code and supporting files for a serverless application that you can deploy with the SAM CLI. It includes the following files and folders.

• chatgpt-bot - Application code for Lambda function. An interaction with ChatGPT enabled bot is provided in Line messaging API.
• template.yaml - A template that defines the application's AWS resources.

Preparations are required prior to deployment of application.

• OpenAI API Key OpenAI
• Line Channel creation for Messaging API Line Developer Console
• Lambda layer packaging and uploading

cd layer
chmod +x package-layer.sh
../package-layer.sh
zip -r python.zip python
aws s3 cp python.zip s3://<your bucket path>

With the preparations above, you will need to jot down information for environmental variables.

• OpenAI API Key
• Channel Access Token

Function URL will be generated when we deploy an application in AWS Lambda. Function URL needs to be configured in Line Developer Console for Lambda invocation.

The Serverless Application Model Command Line Interface (SAM CLI) is an extension of the AWS CLI that adds functionality for building and testing Lambda applications. It uses Docker to run your functions in an Amazon Linux environment that matches Lambda. It can also emulate your application's build environment and API.

To use the SAM CLI, you need the following tools.

• SAM CLI - Install the SAM CLI
• Python 3 installed
• Docker - Install Docker community edition

To build and deploy your application for the first time, run the following in your shell:

sam build --use-container
sam deploy --guided

The first command will build the source of your application. The second command will package and deploy your application to AWS, with a series of prompts:

• Stack Name: The name of the stack to deploy to CloudFormation. This should be unique to your account and region, and a good starting point would be something matching your project name.
• AWS Region: The AWS region you want to deploy your app to.
• Confirm changes before deploy: If set to yes, any change sets will be shown to you before execution for manual review. If set to no, the AWS SAM CLI will automatically deploy application changes.
• Allow SAM CLI IAM role creation: Many AWS SAM templates, including this example, create AWS IAM roles required for the AWS Lambda function(s) included to access AWS services. By default, these are scoped down to minimum required permissions. To deploy an AWS CloudFormation stack which creates or modifies IAM roles, the CAPABILITY_IAM value for capabilities must be provided. If permission isn't provided through this prompt, to deploy this example you must explicitly pass --capabilities CAPABILITY_IAM to the sam deploy command.
• Save arguments to samconfig.toml: If set to yes, your choices will be saved to a configuration file inside the project, so that in the future you can just re-run sam deploy without parameters to deploy changes to your application.

You can find your Function Endpoint URL in the output values displayed after deployment. You will need to configure the Function Endpoint URL in Webhook configuration in Messaging API of your channel.

Build your application with the sam build --use-container command.

$ sam build --use-container

The SAM CLI installs dependencies defined in chatgpt-bot/requirements.txt, creates a deployment package, and saves it in the .aws-sam/build folder.

The application template uses AWS Serverless Application Model (AWS SAM) to define application resources. AWS SAM is an extension of AWS CloudFormation with a simpler syntax for configuring common serverless application resources such as functions, triggers, and APIs. For resources not included in the SAM specification, you can use standard AWS CloudFormation resource types.

To simplify troubleshooting, SAM CLI has a command called sam logs. sam logs lets you fetch logs generated by your deployed Lambda function from the command line. In addition to printing the logs on the terminal, this command has several nifty features to help you quickly find the bug.

NOTE: This command works for all AWS Lambda functions; not just the ones you deploy using SAM.

You can find more information and examples about filtering Lambda function logs in the SAM CLI Documentation.

To delete the sample application that you created, use the AWS CLI. Assuming you used your project name for the stack name, you can run the following:

aws cloudformation delete-stack --stack-name <your stack-name>

See the AWS SAM developer guide for an introduction to SAM specification, the SAM CLI, and serverless application concepts.

Next, you can use AWS Serverless Application Repository to deploy ready to use Apps that go beyond hello world samples and learn how authors developed their applications: AWS Serverless Application Repository main page