# Example

In addition to a basic Lambda function and Express server, the `example`
directory includes a [Swagger file](http://swagger.io/specification/),
[CloudFormation
template](https://aws.amazon.com/cloudformation/aws-cloudformation-templates/)
with [Serverless Application Model
(SAM)](https://github.com/awslabs/serverless-application-model), and helper
scripts to help you set up and manage your application.

## Steps for running the example

This guide assumes you have already [set up an AWS
account](http://docs.aws.amazon.com/AmazonSimpleDB/latest/DeveloperGuide/AboutAWSAccounts.html)
and have the latest version of the [AWS CLI](https://aws.amazon.com/cli/) and
[AWS SAM](https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-sam-cli-install.html)
installed.

1. From your preferred project directory:
  ```sh
    git clone https://github.com/CodeGenieApp/serverless-express.git && cd serverless-express/examples/basic-starter-api-gateway-v2-typescript
  ```
1. Update the `config` section of `package.json` with your `s3BucketName` and
   `region` (optionally, change the `cloudFormationStackName`). If the bucket
   you specify does not yet exist, the next step will create it for you.
1. (optional: domain) If you want to use a custom domain name for your
   application/API, specify it in the `config.domain` section of `package.json`.
   This example assumes the domain is registered in Route53 in the same account
   you're deploying the example to.
1. Run `npm run setup` - this installs the node dependencies, creates an S3
   bucket (if it does not already exist), packages and deploys your serverless
   Express application to AWS Lambda, and creates an API Gateway proxy API.
1. (optional: domain) If you specify a domain, the example will create an SSL
   Certificate via Amazon Certificate Manager; create an API Gateway Domain Name
   record which maps the domain to the API and Stage; and create a Route53
   HostedZone and RecordSet with an A record pointing at the API Gateway Domain
   Name's CloudFront Distribution.
   1. During deployment you should receive an email at one of the registered
      email addresses for the domain. Approve the SSL Certificate by clicking
      the link in the email. The stack creation will pause while waiting for
      this approval.
   1. Wait for stack creation to complete and update Route53 Domain Name to use
      the Name Servers from the created Hosted Zone NS Record (don't include the
      trailing '.') via the AWS console.
   1. It may take several hours before the DNS records propagate.
1. After the setup command completes, open the AWS CloudFormation console
   https://console.aws.amazon.com/cloudformation/home and switch to the region
   you specified. Select the `ServerlessExpressStack` stack (or the stack name
   you specified for `cloudFormationStackName`), then click the `ApiUrl` value
   under the __Outputs__ section - this will open a new page with your running
   API. The API index lists the resources available in the example Express
   server (`app.js`), along with example `curl` commands.
1. (optional) To enable the `invoke-lambda` `package.json` `script`: copy the
   `LambdaFunctionName` from the CloudFormation Outputs and paste it into the
   `package.json` `config`'s `functionName` property.
    Run `npm run invoke-lambda` to invoke the Lambda Function with the payload
    specified in `api-gateway-event.json`.

See the sections below for details on how to migrate an existing (or create a
new) Node.js project based on this example. If you would prefer to delete AWS
assets that were just created, simply run `npm run delete-stack` to delete the
CloudFormation Stack, including the API and Lambda Function. If you specified a
new bucket in the `config` command for step 1 and want to delete that bucket,
run `npm run delete-bucket`.

## Creating or migrating a Node.js project based on the example

To use this example as a base for a new Node.js project:

1. Copy the files in the `examples/basic-starter-api-gateway-v2-typescript`
   directory into a new project directory (`cp -r
   ./examples/basic-starter-api-gateway-v2-typescript
   ~/projects/my-new-node-project`). If you have not already done so, follow the
   [steps for running the example](#steps-for-running-the-example) (you may want
   to first modify some of the resource names to something more
   project-specific, eg. the CloudFormation stack, Lambda function, and API
   Gateway API).
1. After making updates to `app.js`, simply run `npm run package-deploy`.

To migrate an existing Node server:

1. Copy the following files from this directory: `api-gateway-event.json`,
   `sam-template.yaml`, and `lambda.js`. Additionally, copy the `scripts` and
   `config` sections of `example/package.json` into your existing
   `package.json` - this includes many helpful commands to manage your AWS
   serverless assets and perform _basic_ local simulation of API Gateway and
   Lambda. If you have not already done so, follow the [steps for running the
   example](#steps-for-running-the-example).
1. From your existing project directory, run
  ```sh
  npm install --save @codegenie/serverless-express
  ```
1. Modify `lambda.ts` to import your own server configuration (eg. change
   `require('./app')` to `require('./server')`). You will need to ensure you
   export your app configuration from the necessary file (eg. `module.exports =
   app`). This library takes your app configuration and listens on a Unix Domain
   Socket for you, so you can remove your call to `app.listen()`.
1. Modify the `CodeUri` property of the Lambda function resource in
   `sam-template.yaml` to point to your application directory (e.g. `CodeUri:
   ./src`). If you are using a build tool (e.g. Gulp, Grunt, Webpack, Rollup,
   etc.), you will instead want to point to your build output directory.
1. Run `npm run package-deploy`.

To perform a basic, local simulation of API Gateway and Lambda with your Node
server, update `api-gateway-event.json` with some values that are valid for your
server (`httpMethod`, `path`, `body` etc.) and run `npm run local`.

If you need to make modifications to your API Gateway API or other AWS
resources, modify `sam-template.yaml` and run `npm run package-deploy`.

## Node.js version

This example was written against Node.js 12

## Development

To update this example against the latest local changes to
@codegenie/serverless-express:

```bash
npm i ../..
npm run build
npm run local
```
