shorty

Shorty is a turn-key link shortening service, including deployment scripts that support custom domains. With a few minutes of work you can have your own link shortening service on your own custom domain!

Or, you know, throw out the link shortener code entirely and bring your own app!

There's a lot in here so let's break it down:

We have:

• A super simple serverless backend api
• A dead simple static website
• User authentication
• Link shortening
• Link expanding

On a technology front we have:

• Several AWS Services (Lambda, DynamoDB, API Gateway, S3, Cognito, IAM)
• AWS SAM tool for creating and deploying the serverless api
• Github for version control and Github Actions for cicd
• Cloudflare for DNS hosting

The goal is to take you from git push to https://your-domain.com

Step one.. clone this repo!

Important files

This project contains source code and supporting files for a serverless application built using the AWS Serverless Application Model (AWS SAM) tool, a CI/CD pipeline in Github, and Cloudflare DNS hosting. It includes the following files and folders:

• template.yaml - A template that defines the application's AWS resources.
• .github/workflows/deploy.yaml - A template that defines the Github Actions ci/cd pipeline.
• website/shorty.template - A template for generating the static website during deployment. This template is hard-coded to the "us-west-2" AWS Region.
• src - Javascript code for the application's Lambda function.
• __tests__ - Unit tests written in Jest for the application code.
• events - Invocation events that you can use to locally invoke the function using aws sam invoke
• sample-iam-user-policy.json - Amazon IAM Policy document describing the AWS permissions needed for deployment to AWS.
• samconfig.toml - SAM CLI config file, it is hard-coded to the "us-west-2" AWS Region.

Configure your environment

Okay there's a lot to do here, but it's a full solution so hang in there!

Things you need:

1. Amazon Web Services account with one AWS IAM account who has permissions to perform the deployment a. The permissions needed are documented in sample-iam-user-policy.json b. This user must have an active AWS Access Key
2. Github account and the ability to clone this repo, run Github Actions, and save Actions Secrets
3. Cloudflare account (and apikey) for DNS hosting and SSL certificate generation

__## Deploy the application

Deployment for this solution is automated using Github Actions. When you make changes to the solution and push those changes to the 'main' branch, the Github Actions deployment pipeline executes, creating the required AWS resources and deploying the latest version of your code.

1. Create a new AWS IAM User for Github with a set of Access Keys. Attach an IAM security policy that matches your environment (see sample-iam-user-policy.json)

2. Go to Cloudflare and generate an SSL cert for your hosted custom domain

3. Import your SSL certificate into AWS Certificate Manager (ACM)

4. Create the following Repository Secrets in the Github Actions section of your Github repo a. AWS_ACCESS_KEY_ID = Your AWS Access Key b. AWS_SECRET_ACCESS_KEY = Your AWS Secret Access Key c. AWS_REGION = Your preferred AWS Region d. ACM_CERT_ARN = The ARN of the SSL certificate you have in AWS Certificate Manager e. API_DOMAIN = This is your custom domain name ("your-domain.com") f. CLOUDFLARE_ZONE_ID = Your Cloudflare domain's Zone ID g. CLOUDFLARE_API_TOKEN = Your Cloudflare API Key

5. Edit the samconfig.toml file and ensure the region matches the AWS_REGION value.

6. Push the main branch of your project to Github to kick off the Github Actions

7. Watch the deployment from Github Actions. When successful you should be able to find the StaticWebsiteURL in the deploy logs. Load that up in your browser and see if it works!

Local Development and Testing

The AWS 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. We use the AWS SAM CLI within Github Actions to do all the heavy lifting, so understanding how we use it locally can be helpful.

To use the AWS SAM CLI, you need the following tools:

• AWS SAM CLI - Install the AWS SAM CLI.
• Node.js - Install Node.js 22, including the npm package management tool.
• Docker - Install Docker community edition.

To build and deploy your application manually, run the following in your shell:

sam build
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.

The API Gateway endpoint API and static webpage url will be displayed in the outputs when the deployment is complete.

Use the AWS SAM CLI to build and test locally

Build your application by using the sam build command.

my-application$ sam build

The AWS SAM CLI installs dependencies that are defined in package.json, creates a deployment package, and saves it in the .aws-sam/build folder.

Test a single function by invoking it directly with a test event. An event is a JSON document that represents the input that the function receives from the event source. Test events are included in the events folder in this project.

Run functions locally and invoke them with the sam local invoke command.

my-application$ sam local invoke getLinkByShortIdFunction --event events/event-get-link-by-shortid.json
my-application$ sam local invoke postLinkFunction --event events/event-post-link.json

The AWS SAM CLI can also emulate your application's API. Use the sam local start-api command to run the API locally on port 3000.

my-application$ sam local start-api
my-application$ curl http://localhost:3000/

The AWS SAM CLI reads the application template to determine the API's routes and the functions that they invoke. The Events property on each function's definition includes the route and method for each path.

      Events:
        Api:
          Type: Api
          Properties:
            Path: /
            Method: GET

Fetch, tail, and filter Lambda function logs

To simplify troubleshooting, the AWS SAM CLI has a command called sam logs. sam logs lets you fetch logs that are generated by your 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 Lambda functions, not just the ones you deploy using AWS SAM.

my-application$ sam logs -n postLinkFunction --stack-name shorty --tail

NOTE: This uses the logical name of the function within the stack. This is the correct name to use when searching logs inside an AWS Lambda function within a CloudFormation stack, even if the deployed function name varies due to CloudFormation's unique resource name generation.

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

Unit tests

Tests are defined in the __tests__ folder in this project. Use npm to install the Jest test framework and run unit tests.

my-application$ npm install
my-application$ npm run test

Cleanup

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:

sam delete --stack-name shorty

Resources

For an introduction to the AWS SAM specification, the AWS SAM CLI, and serverless application concepts, see the AWS SAM Developer Guide.

Next, you can use the AWS Serverless Application Repository to deploy ready-to-use apps that go beyond Hello World samples and learn how authors developed their applications. For more information, see the AWS Serverless Application Repository main page and the AWS Serverless Application Repository Developer Guide.

Learn more about Github Actions directly from the source.