WebFunc ·

WARNING:

This project is no longer supported. If you still plan on using this project, be aware that it does not support Zeit Now >= 2.0. We are currently working on a replacement project that we hope to release very soon. Thank you for your support. 

The Neap Team

WebFunc ·

Universal Serverless Web Framework. Write code for serverless similar to Express once, deploy everywhere (thanks to the awesome Zeit Now-CLI). This also include creating functions that can get triggered by Google Cloud PubSub topics. Targeted platforms:

Zeit Now (using express under the hood)
Google Cloud Functions (incl. reacting to Pub/Sub events or Storage changes)
AWS Lambdas
Azure Functions (COMING SOON...)

const { app } = require('webfunc')

app.get('/users/:username', (req, res) => res.status(200).send(`Hello ${req.params.username}`))

eval(app.listen('app', 4000))

Webfunc supports Express middleware.

Forget any external dependencies to run your serverless app locally. Run node index.js and that's it.

Out-of-the-box features include:

Routing
CORS
Body & Route Variables Parsing
Environment Variables Per Deployment
Middleware (incl. Express)

Install

How To Use It

Basic - Build Once Deploy Everywhere

Passing Parameters To Your HTTP Endpoint

Webfunc Properties On The Request Object

Deploying To Google Functions or AWS

Examples

Creating A REST API

Compatible With All Express Middleware

Managing Environment Variables Per Deployment

Intercepting The res.send() Method

Reacting To Google PubSub Topics

Authentication

Uploading Files & Images

GraphQL

Configuration

CORS

Disabling Body Or Route Parsing

Customizing The req.params Property

Tips & Tricks

Dev - Easy Hot Reloading

Dev - Better Deployments With now-flow

FAQ

Annexes

A.1. CORS Refresher

A.2. CORS Basic Errors

Contributing

About Neap

License

Install

Prerequisites

To run your function outside of your local machine, you will need to install Zeit Now. The lastest stable version of now that works is @9.0.0. We're currently working on fixing the issues with more recent versions of now.

npm install [email protected] -g

Install Webfunc

npm install webfunc --save

How To Use It

Basic - Build Once Deploy Everywhere

To deploy your app to any serverless solution, first make sure you have installed Zeit Now globally:

npm install now -g

1. Create an index.js:

const { app } = require('webfunc')

app.get('/users/:username', (req, res) => res.status(200).send(`Hello ${req.params.username}`))

eval(app.listen('app', 4000))

More details on why eval is used under What does webfunc use eval() to start the server? in the FAQ.

2. Add a "start" script in your package.json

  "scripts": {
    "start": "node index.js"
  }

3.A. Deploy locally without any other dependencies

npm start

3.B. Deploy to Zeit Now

now

3.C. Deploy to Google Cloud Function

Add a now.json file similar to the following:

{
  "gcp": {
    "memory": 128,
    "functionName": "webfunctest",
    "timeout": "100s"
  },
  "environment":{
    "active": "staging",
    "default":{
      "hostingType": "localhost"
    },
    "staging":{
      "hostingType": "gcp"
    }
  }
}

Run this command:

now gcp

The environment.active = "staging" indicates that the configuration for your app is inside the environment.staging property. There, you can see "hostingType": "gcp". Webfunc uses the hostingType property to define how to serve your app (this is indeed different from platform to platform. Trying to deploy a "hostingType": "gcp" to Zeit Now will fail).

NOTE: Weird timeout convention Notice that the timeout used in for gcp is in seconds not millisends. Also, you have to specify the unit at the end: "timeout": "100s".

3.D. Deploy to Google Cloud Function For Pub/Sub or Storage Based Triggers or Deploy to AWS Lambda

You will need to enhance the now-CLI capabilities by adding a dev dependency called now-flow.js. An example if available in section Google Pub/Sub Topic & Storage Trigger Based Functions.

HIGHLY RECOMMENDED - USE now-flow.js TO MANAGE YOUR DEPLOYMENTS
Without now-flow.js, you won't be able to deploy to AWS or to GCP using a Pub/Sub topic trigger. now-flow.js is not just about adding other deployment options to webfunc. It also tremendously helps to managing environment variables per deployment).

Passing Parameters To Your HTTP Endpoint

Whether your passing parameters in the URL route, the querystring, or the HTTP body, webfunc will parse those arguments and store them into as a JSON in the req.params property. Here is an example of a GET to the following URL: https://yourapp.com/users/frank?lastname=fitzerald

app.get('/users/:username', (req, res) => res.status(200).send(`Hello ${req.params.username} ${req.params.lastname}`))

Webfunc Properties On The request Object

The first operation made by webfunc when it receives a request is to add 3 properties on the request object:

__receivedTime: Number that milliseconds since epoc when the request reaches the server.
__transactionId: String representing a unique identifier (e.g. useful for tracing purposes).
__ellapsedMillis: Function with no arguments returning the number of milliseconds ellapsed since __receivedTime.

Deploying To Google Functions or AWS

IMPORTANT: Before deploying to Google Functions (GCP), YOU'LL HAVE TO ENABLE BILLING under the specific project hosting your function. Simply browse to your account (https://console.cloud.google.com/), click on the Cloud Functions, and then click on Enable Billing.

You will need to enhance the now-CLI capabilities by adding a dev dependency called now-flow.js. An example if available in section Google Pub/Sub Topic & Storage Trigger Based Functions.

Before deploying to GCP or AWS, you'll have to login first using:

now gcp login

or

now aws login

After using one of the above command, you'll be prompt to select a project within your GCP or AWS account. Once selected, your function will be deployed withing that project.

To change to another project, re-rerun the commands above.

HIGHLY RECOMMENDED - USE now-flow.js TO MANAGE YOUR DEPLOYMENTS
Without now-flow.js, you won't be able to deploy to AWS or to GCP using a Pub/Sub topic trigger. now-flow.js is not just about adding other deployment options to webfunc. It also tremendously helps to managing environment variables per deployment).

Examples

Creating A REST API

A REST api is cool but GraphQL is even cooler. Check out how you can create a GraphQL api in less than 2 minutes here.

Single Endpoint

index.js:

const { app } = require('webfunc')

app.get('/users/:username', (req, res) => res.status(200).send(`Hello ${req.params.username}`))

eval(app.listen('app', 4000))

To run this code locally, simply run in your terminal:

node index.js

To speed up your development, use hot reloading as explained in the Tips & Tricks section below.

Multiple Endpoints

const { app } = require('webfunc')

// 1. Simple GET method. 
app.get('/users/:username', (req, res) => 
  res.status(200).send(`Hello ${req.params.username}`))

// 2. GET method with more variables in the route. The conventions are the same as
//    the 'path-to-regex' module (https://github.com/pillarjs/path-to-regexp).
app.get('/users/:username/account/:accountId', (req, res) => 
  res.status(200).send(`Hello ${req.params.username} (account: ${req.params.accountId})`))

// 3. Support for multiple routes pointing to the same action.
app.get(['/companies/:companyName', '/organizations/:orgName'], (req, res) => 
  res.status(200).send(req.params.companyName ? `Hello company ${req.params.companyName}` : `Hello organization ${req.params.orgName}`))

// 4. Supports all http verbs: GET, POST, PUT, DELETE, HEAD, OPTIONS.
app.post('/login', (req, res, params={}) => {
  if (req.params.username == 'nic' && req.params.password == '123')
    res.status(200).send(`Welcome ${req.params.username}.`)
  else
    res.status(401).send('Invalid username or password.')
})

// 5. Supports route for any http verb.
app.all('/', (req, res) => res.status(200).send('Welcome to this awesome API!'))

eval(app.listen('app', 4000))

Notice that in all the cases above, the req.params argument contains any parameters that are either passed in the route or in the payload. This scenario is so common that webfunc automatically supports that feature. No need to install any middleware like body-parser. Webfunc can even automatically parse multipart/form-data content type usually used to upload files (e.g. images, documents, ...). More details under Uploading Images in the Use Cases section.

Based on certain requirements, it might be necessary to disable this behavior. To do so, please refer to Disabling Body Or Route Parsing under the Configuration section.

Compatible With All Express Middleware

That's probably one of the biggest advantage of using webfunc. Express offers countless of open-sourced middleware that would not be as easily usable in a FaaS environment without webfunc. You can for example use the code you're to write in Express to write functions that react to a Google Cloud Pub/Sub topic.

Next, we'll demonstrate 4 different basic scenarios:

Using An Express Middleware Globally
Using An Express Middleware On a Specific Endpoint Only
Creating Your Own Middleware
Chaining Multiple Middleware On a Specific Endpoint

Using An Express Middleware Globally

const { app } = require('webfunc')
const responseTime = require('response-time')

app.use(responseTime())

app.get('/users/:username', (req, res) => 
  res.status(200).send(`Hello ${req.params.username}`))

app.get('/users/:username/account/:accountId', (req, res) => 
  res.status(200).send(`Hello ${req.params.username} (account: ${req.params.accountId})`))

eval(app.listen('app', 4000))

The snippet above demonstrate how to use the Express middleware response-time. This middleware measures the time it takes for your server to process a request. It will add a new response header called X-Response-Time. In this example, all APIs will be affected.

Using An Express Middleware On a Specific Endpoint Only

Similar to Express, webfunc allows to target APIs specifically:

const { app } = require('webfunc')
const responseTime = require('response-time')

app.get('/users/:username', responseTime(), (req, res) => 
  res.status(200).send(`Hello ${req.params.username}`))

app.get('/users/:username/account/:accountId', (req, res) => 
  res.status(200).send(`Hello ${req.params.username} (account: ${req.params.accountId})`))

eval(app.listen('app', 4000))

In the snippet above, the response-time will only affect the first API.

Creating Your Own Middleware

Obviously, you can also create your own middleware the exact same way you would have done it with Express, which means you'll also be able to use it with Express:

const { app } = require('webfunc')

const authenticate = (req, res, next) => {
  if (!req.headers['Authorization'])
    res.status(401).send(`Missing 'Authorization' header.`)
  next()
}

app.use(authenticate)

app.get('/users/:username', (req, res) => 
  res.status(200).send(`Hello ${req.params.username}`))

app.get('/users/:username/account/:accountId', (req, res) => 
  res.status(200).send(`Hello ${req.params.username} (account: ${req.params.accountId})`))

eval(app.listen('app', 4000))

Chaining Multiple Middleware On a Specific Endpoint

For more complex scenario, you may need to chain multiple middleware differently depending on the endpoint:

const { app } = require('webfunc')

const doSomething = (req, res, next) => {
  // Notice that it might be wise to take some precaution and not override the 'req.params'
  // property, which might have been used a previous middleware.
  if (!req.params || typeof(req.params) != 'object')
    req.params = {}
  Object.assign(req.params, { part_1: 'nice' })
  next()
}

const doSomethingElse = (req, res, next) => {
  if (!req.params || typeof(req.params) != 'object')
    req.params = {}
  Object.assign(req.params, { part_2: 'to see you' })
  next()
}

// One way to chain:
app.get('/users/:username', doSomething, doSomethingElse, (req, res) => 
  res.status(200).send(`Hello ${req.params.username}, ${req.params.part_1} ${req.params.part_2}`))

// Another way to chain:
const middleware = [doSomething, doSomethingElse]

app.get('/', ...middleware.concat((req, res) => 
  res.status(200).send(`Hello ${req.params.part_1} ${req.params.part_2}`)))

eval(app.listen('app', 4000))

Managing Environment Variables Per Deployment

The following code allows to access the current active environment's variables:

const { appConfig } = require('webfunc')
console.log(appConfig.myCustomVar) // > "Hello Default"

appConfig is the configuration inside the now.json under the active environment (the active environment is the value of the environment.active property).

Here is an example of a typical now.json file:

{
  "environment": {
    "active": "default",
    "default": {
      "hostingType": "localhost",
      "myCustomVar": "Hello Default"
    },
    "staging": {
      "hostingType": "gcp",
      "myCustomVar": "Hello Staging"
    },
    "production": {
      "hostingType": "now",
      "myCustomVar": "Hello Prod"
    }
  }
}

As you can see, the example above demonstrates 3 different types of environment setups: "default", "staging", "prod". You can obviouly define as many as you want, and add whatever you need under those environments. Since the value of the environment.active is "default" in this example, the value of the appConfig object is:

{
  "hostingType": "localhost",
  "myCustomVar": "Hello Default"
}

Intercepting The res.send() Method

Webfunc adds support for listeners on the following 3 response events:

sending a response.
setting the headers of a response.
setting the status of a response.

const { app } = require('webfunc')

app.on('send', (req, res, val) => console.log(val))
app.on('headers', (req, res, ...args) => console.log(args))
app.on('status', (req, res, val) => console.log(val))

app.get('/users/:username', (req, res) => {
  res.set('x-special', 'magic header')
  res.status(200).send(`Hello ${req.params.username}`)
})

eval(app.listen('app', 4000))

Reacting To Google PubSub Topics

One of the goals of Webfunc was to provide a uniform API for building serverless functions. Serverless functions can react to more than HTTP requests, and in this section, we will demonstrate how to build and deploy a Google Cloud Function that can react to messages published to a Google PubSub topic. This section is broken down in 3 parts:

Intro - Here we will show how to test a function locally, deploy it to Google Cloud, and then manually test it by publishing a message on a topic.
Minimum Message Requirement - In this section, we will briefly explain the requirement for the messages that can be published so that the function can react to them.
Programmatically Publish To Google PubSub - Though this is not really relevant to Webfunc, it is still something we expect any coder will eventually do, so we thought that a little help might be useful.

Intro

PREREQUISITES:

CREATING A GOOGLE CLOUD PUBSUB TOPIC

Before you can start deploying a webfunc function to Google Cloud that can react to a Google PubSub topic, you will have to do the following:

Create a Google Cloud Account or logging to your Google Cloud console (https://console.cloud.google.com). Don't worry, it is free!

Create a new project, or select an existing one.

Enable billing on both Google Cloud Function and Google Cloud PubSub (simply click on those items in the menu and if the billing has not been turned on, then a pop up will appear with a simple button "enable billing". Those services are free unless you exceed the free quota).

Browse to Google PubSub and create your first topic called 'hello-webfunc'.

INSTALL NOW-FLOW FOR EASIER DEPLOYMENTS TO GOOGLE CLOUD

now-flow automates your Zeit Now deployments and will decrease the configuration setup. Simply run npm install now-flow --save-dev.

Because Express has become such a familiar tool, our team decided to embrace its API conventions, even for functions reacting to events other than HTTP requests. If you're interested in seeing an example of how you would build a normal function using the standard Google API, please refer to this documentation. The other reason we found it was very useful to use an Express convention for building any function is testability. Indeed, because Webfunc treats any event as a web request, it is very easy to test your function locally using a standard HTTP POST containing the event payload. We will demonstrate this by creating a simple email notification function that reacts to messages dropped on the Google Cloud PubSub topic we created in the prerequiste steps:

Configure now to use the Google project we defined in the prerequisite steps: now gcp login (once you're logged in, you'll be asked to choose a project in your CLI. Choose the project we created in the prerequisite steps)
Create a new npm project: npm init
Install nodemailer to send a dummy email: npm install nodemailer --save
Create a new index.js as follow:

const { app } = require('webfunc')
const nodemailer = require('nodemailer');

app.post('/sayhi', (req, res) => {
  // STEP 1. Get payload
  const { to, subject, message } = req.params

  // STEP 2. Send email
  // Generate test SMTP service account from ethereal.email
  // Only needed if you don't have a real mail account for testing
  nodemailer.createTestAccount((err, account) => {
    // create reusable transporter object using the default SMTP transport
    let transporter = nodemailer.createTransport({
      host: 'smtp.ethereal.email',
      port: 587,
      secure: false, // true for 465, false for other ports
      auth: {
        user: account.user, // generated ethereal user
        pass: account.pass // generated ethereal password
      }
    })

    // setup email data with unicode symbols
    let mailOptions = {
      from: '"Webfunc 👻" <[email protected]>', // sender address
      to: to,
      subject: subject,
      html: message
    }

    // send mail with defined transport object
    transporter.sendMail(mailOptions, (error, info) => {
      if (error) {
        console.error(error)
        res.status(500).send(error)
      }
      else {
        const msg = `Message sent: ${info.messageId}\nPreview URL: ${nodemailer.getTestMessageUrl(info)}`
        console.log(msg)
        res.status(200).send(msg)
      }
    })
  })
})

eval(app.listen('app', 4000))

IMPORTANT: When it comes to create a webfunc function reacting to events other than HTTP requests, only POST methods are allowed.

Start the server locally to start testing this code: node index.js
Test this code locally:

curl -X POST -H 'Content-Type: application/json' -d '{"to":"[email protected]","subject":"PubSub with Webfunc", "message": "<b>PubSub with Webfunc is easy mate!!!</b>"}' http://localhost:4000/sayhi

This will return a message similar to:

Message sent: <[email protected]>
Preview URL: https://ethereal.email/message/WpuwmIPHUAoowF06WpufewfwpxLDDPAAAAAYyFpXXAobCBPcRN5IvxKV0

Copy/paster the Preview URL in your browser to visualise your test email.

What the above achieved is nothing different from what we've been demonstrating previously. Let's deploy this code to a Google Cloud Function that should be responding to messages published to the topic we created in the prerequisite steps above:

Create a new now.json file as follow:

{
  "environment": {
    "active": "default",
    "default": {
      "hostingType": "localhost"
    },
    "prod": {
      "hostingType": "gcp",
      "gcp": {
        "functionName": "webfunc-pubsub",
        "memory": 128,
        "trigger": {
          "type": "cloud.pubsub",
          "topic": "hello-webfunc"
        }
      }
    }
  }
}

This config file defines a production environment prod that contains the details of the Google Cloud Function we want to deploy as well as the PubSub topic we want it to react to (i.e. hello-webfunc created in the prerequisite steps).

Add a deployment script in the package.json as follow:

"scripts": {
  "deploy": "nowflow prod"
}

Deploy your function: npm run deploy

WARNING: There seems to be a bug the first time you deploy. A failed deployment error might happen when in reality the deployment was successful. Double-check that your function has been created in your Google Function console.

Publish a message to the hello-webfunc topic to see if this function reacts to it:

Go to the Google PubSub console.
Select the hello-webfunc topic.
Click on the PUBLISH MESSAGE button.
Add the following 4 key/value pairs and then press Publish:

Key	Value
to	[email protected]
subject	Testing Webfunc PubSub
message	`<h1>Hi there</h1><p>Webfunc is awesome!</p>`
pathname	sayhi

IMPORTANT - Notice that we need to add a new field called pathname. This is what allows to target a specific endpoint (in this case app.post('/sayhi', (req, res) => { ... })).

Verify that this worked by checking the Google Function log. There, you should see the Preview URL and then browse there to verify that everything is working fine.

Minimum Message Requirement

As we demonstrated in the example above, the structure of the published message can be anything BUT IT MUST AT LEAST CONTAIN A pathname property. That pathname property is required to allow webfunc to identify which endpoint it needs to route that message to.

Programmatically Publish To Google PubSub

Get a JSON file containing a private key that allows to publish to the Google PubSub topic:

Log to your Google Cloud project.
Browse to the Service Accounts section under IAM & admin/Service accounts.
Click on the CREATE SERVICE ACCOUNT button. There give it a name, select the role PubSub/PubSub Publisher and then tick the Furnish a new private key (select JSON format) checkbox before clicking the CREATE button.
Save that json file under your project and let's rename it secrets.json for the sake of this example.

Install @google-cloud/pubsub: npm install @google-cloud/pubsub --save
Create a new publish.js as follow:

const path = require('path')

const GOOGLE_PROJECT = 'your-google-project-name'
const TOPIC_NAME = 'hello-webfunc'
const SECRETS_PATH = path.join(process.cwd(), './secrets.json')

const pubsub = require('@google-cloud/pubsub')({
  projectId: GOOGLE_PROJECT,
  keyFilename: SECRETS_PATH
})

const topic = pubsub.topic(TOPIC_NAME)
const publisher = topic.publisher()
const emptyBuffer = Buffer.from('')

const publish = (data={}) => new Promise((onSuccess, onFailure) => publisher.publish(emptyBuffer, data, (err, res) => err ? onFailure(err) : onSuccess(res)))

publish({
  to: '[email protected]',
  subject: 'Webfunc ♥ Google PubSub',
  message: '<h1>Love Story</h1><b>Webfunc and Google PubSub rock together.</b>',
  pathname: 'sayhi'
})
.then(() => console.log(`Great!!! Message sent!`))
.catch(err => console.error(`Dammit! Somthing went wrong:\n${err.message}\n${err.stack}`))

Excute this code: node publish.js

Authentication

Authentication using webfunc is left to you. That being said, here is a quick example on how that could work using the awesome passport package. The following piece of code for Google Cloud Functions exposes a signin POST endpoint that expects an email and a password and that returns a JWT token. Passing that JWT token in the Authorization header using the bearer scheme will allow access to the / endpoint.

const { app } = require('webfunc')
const jwt = require('jsonwebtoken')
const passport = require('passport')
const { ExtractJwt, Strategy } = require("passport-jwt")

const SECRETKEY = 'your-super-secret-key'
const jwtOptions = {
  jwtFromRequest: ExtractJwt.fromAuthHeaderWithScheme('bearer'),
  secretOrKey: SECRETKEY
}

passport.use(new Strategy(jwtOptions, (decryptedToken, next) => {
  // do more verification based on your requirements.
  return next(null, decryptedToken)
}))

const authenticate = () => (req, res, next) => passport.authenticate('jwt', (err, user) => {
  if (user) {
    // Notice that it might be wise to take some precaution and not override the 'req.params'
    // property, which might have been used a previous middleware.
    if (!req.params || typeof(req.params) != 'object')
      req.params = {}
    Object.assign(req.params, { user })
    next()
  }
  else
    res.status(401).send(`You must be logged in to access this endpoint!`)
})(req, res)

// This api does not require authentication. It is used to acquire the bearer token.
app.post('/signin', (req, res) => {
  if (req.params.email == '[email protected]' && req.params.password == 'supersecuredpassword') {
    const user = {
      id: 1,
      roles: [{
        name: 'Admin',
        company: 'neap pty ltd'
      }],
      username: 'neapnic',
      email: '[email protected]'
    }
    res.status(200).send({ message: 'Successfully logged in', token: jwt.sign(user, SECRETKEY) })
  }
  else
    res.status(401).send(`Username or password invalid!`) 
})

// This api requires authentication. You must pass a header names "Authorization"
app.get('/', authenticate(), (req, res) => res.status(200).send(`Welcome ${req.params.user.username}!`))

eval(app.listen('app', 4000))

To test that piece of code:

1. Login:

curl -X POST -H 'Content-Type: application/json' -d '{"email":"[email protected]","password":"supersecuredpassword"}' http://localhost:4000/signin

Extract the token received from this POST request and use it in the following GET request's header:

2. Access the secured / endpoint:

curl -v -H "Authorization: Bearer your-jwt-token" http://localhost:4000

Uploading Files & Images

As mentioned before, webfunc's default behavior is to automatically extract the payload as well as the route variables into a json object. This includes the request with a multipart/form-data content type. In that case, an object similar to the following will be stored under req.params.yourVariableName:

{
  filename: "filename.ext",
  mimetype: "image/png",
  value: <Buffer>
}

where

filename is a string representing the name of the uploaded file.
mimetype is a string representing the mimetype of the uploaded file (e.g. 'image/png').
value is a Buffer representing the uploaded file itself.

Here is a code snippet that shows how to store the uploaded file locally:

const { app } = require('webfunc')
const path = require('path')
const fs = require('fs')

const save = (filePath, data) => new Promise((onSuccess, onFailure) => fs.writeFile(filePath, data, err => {
  if (err) {
    console.error(err)
    onFailure(err)
  }
  else
    onSuccess()
}))

app.post('/upload', (req, res) => 
  save(path.join(process.cwd(), req.params.myimage.filename), req.params.myimage.value)
  .then(() => res.status(200).send('Upload successfull'))
  .catch(err => res.status(500).send(err.message))
)

eval(app.listen('app', 4000))

You can test this code locally by using Postman as follow:

GraphQL

Deploying a GraphQL api as well as a GraphiQL Web UI to document and test that api has never been easier. GraphQL is beyond the topic of this document. You can learn all about it on the official webpage.

To create your own GraphQL api in a few minutes using webfunc, simply run those commands:

git clone https://github.com/nicolasdao/graphql-universal-server.git
cd graphql-universal-server
npm install
npm start

This will locally host the following:

http://localhost:4000: This is the GraphQL endpoint that your client can start querying.
http://localhost:4000/graphiql: This is the GraphiQL Web UI that you can use to test and query your GraphQL server.

More details about modifying this project for your own project here.

The index.js of that project looks like this:

const { app } = require('webfunc')
const { graphqlHandler } = require('graphql-serverless')
const { transpileSchema } = require('graphql-s2s').graphqls2s
const { makeExecutableSchema } = require('graphql-tools')
const { glue } = require('schemaglue')

const { schema, resolver } = glue('./src/graphql')

const executableSchema = makeExecutableSchema({
  typeDefs: transpileSchema(schema),
  resolvers: resolver
})

const graphqlOptions = {
  schema: executableSchema,
  graphiql: true,
  endpointURL: '/graphiql',
  context: {} // add whatever global context is relevant to you app
}

// The GraphQL api
app.all(['/', '/graphiql'], graphqlHandler(graphqlOptions))

eval(app.listen('app', 4000))

Configuration

CORS

More details about those headers in the Annexes section under A.1. CORS Refresher.

Similar to body parsing, CORS (i.e. Cross-Origin Resource Sharing) is a feature that is so often required that webfunc also supports it out-of-the box. That means that in most cases, the Express CORS middleware will not be necessary.

const { app, cors } = require('webfunc')

// AJAX requests allowed from any domain.
const globalAccess = cors()

// No AJAX requests allowed except from domain than 'https://example.com'.
const restrictedAccess = cors({
  methods: ['GET'],
  allowedHeaders: ['Authorization', 'Origin', 'X-Requested-With', 'Content-Type', 'Accept'],
  origins: ['https://example.com']
})

app.get('/products/:id', globalAccess, (req, res) => res.status(200).send(`This is product ${req.params.id}`))
// The 'OPTIONS' verb is required to allow preflight requests. Indeed, request with headers like 'Authorization' are not considered
// simple requests (ref. https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS). The browser will then do what's called a 
// preflight request using the 'OPTIONS' http method to acquire more data on the server. If the server fails to respond to 
// that 'OPTIONS' request, the browser will abort the request.
app.options('/users/:username', restrictedAccess)
app.get('/users/:username', restrictedAccess, (req, res) => res.status(200).send(`Hello ${req.params.username}`))

eval(app.listen('app', 4000))

CORS is a classic source of headache. Though webfunc allows to easily configure any project, it will not prevent you to badly configure a project, and therefore loose a huge amount of time. For that reason, a series of common mistakes have been documented in the Annexes section under A.2. CORS Basic Errors.

Disabling Body Or Route Parsing

Webfunc's default behavior is to parse both the payload and any variables found in the route into a JSON object (see previous example). Based on certain requirements, it might be necessary to disable that behavior (e.g. trying to read the payload again in your app might not work after webfunc has parsed it).

To disable completely or partially that behavior, add a "params" property in the now.json configuration file in the root of your application as follow:

Example of a now.json config that disable the payload parsing only:

{
  "params": { mode: "route" }
}

That mode property accepts 4 modes:

all: (default) Both the payload and the route variables are extracted.
route: Only the variables from the route are extracted. The payload is completely ignored.
body: Only the payload is parsed. The route variables are completely ignored.
none: Neither the payload nor the route variables are extracted.

If the params property or the mode are not defined in the now.json, then the default mode is all.

Customizing The req.params Property

If the params property conflicts with some middleware or other 3rd party systems, you can change that property name. Just configure the now.json as follow:

{
  "params": { propName: "somethingElse" }
}

The configuration above with replace req.params to req.somethingElse.

Tips & Tricks

Dev - Easy Hot Reloading

While developing on your localhost, we recommend using hot re loading to help you automatically restart your node process after each change. node-dev is a lightweight development tools that watches the minimum amount of files in your project and automatically restart the node process each time a file has changed.

npm install node-dev --save-dev

Change your start script in your package.json from "start": "node index.js" to:

  "scripts": {
    "start": "node-dev index.js"
  }

Then simply start your server as follow:

npm start

Dev - Better Deployments With now-flow

Overview - Deploy To AWS, Add Google Pub/Sub Topic Trigger Based Functions & Automate Deployments

As we've see it above, a now.json configuration becomes quickly necessary. Almost all projects will end up needing multiple environment configurations (i.e. prod, staging, ...) and environment variables specific to them (more info in section Managing Environment Variables Per Deployment). Though it is really straightforward to configure the now.json file, it can be annoying as well as error-prone to modify it prior to each deployment (e.g. deploying to the staging environment requires to set up the "active" property to "staging". Another classic example is to deploy to multiple gcp environments. In that case, you will have to update the "gcp" property prior to each deployment). Beside, as of version 9.2.5., now-CLI still experiences bugs while deploying to AWS and simply can't deploy Google Functions that can be triggered by Pub/Sub topics.

For all the reason above, we developed now-flow. It is a simple dev dependency that you should add to your project. It controls the now-CLI while enhancing its capabilities. Simply define all your configurations specific to each environment inside your usual now.json, and let NowFlow do the rest.

No more deployment then aliasing steps. No more worries that some environment variables have been properly deployed to the right environment.

More details about now-flow here.

How To Use It

HTTPS Endpoints

Install it first in your project:

npm install now-flow --save-dev

Then configure your now.json for each of your environment:

{
  "environment": {
    "active": "default",
    "default": {
      "hostingType": "localhost",
      "db": {
        "user": "postgres",
        "password": "bla_staging_bla_staging"
      }
    },
    "staging": {
      "hostingType": "gcp",
      "db": {
        "user": "postgres",
        "password": "bla_staging_bla_staging"
      },
      "gcp": {
        "functionName": "yourapp-test",
        "memory": 128
      }
    },
    "uat": {
      "hostingType": "aws",
      "db": {
        "user": "postgres",
        "password": "bla_staging_bla_staging"
      },
      "aws": {
        "memory": 128,
        "region": "ap-southeast-2"
      }
    },
    "prod": {
      "hostingType": "now",
      "db": {
        "user": "postgres",
        "password": "bla_prod_bla_prod"
      },
      "scripts": {
        "start": "NODE_ENV=production node index.js"
      },
      "alias": "yourapp-prod"
    }
  }
}

Add new deployment scripts in your package.json:

"scripts": {
  "deploy:staging": "nowflow staging",
  "deploy:uat": "nowflow uat",
  "deploy:prod": "nowflow prod",
}

Now you can deploy to gcp, aws or now using the exact same code:

Deploying to gcp (make sure you have run now gcp login at least once before):

npm run deploy:staging

Deploying to aws (make sure you have run now aws login at least once before):

npm run deploy:uat

Deploying to now (make sure you have run now login at least once before):

npm run deploy:prod

Google Pub/Sub Topic & Storage Trigger Based Functions

Simply add configurations similar to the following into the now.json:

{
  "environment": {
    "active": "default",
    "default": {
      "hostingType": "localhost"
    },
    "example1": {
      "hostingType": "gcp",
      "gcp": {
        "functionName": "yourapp-test",
        "memory": 128,
        "trigger": {
          "type": "cloud.pubsub",
          "topic": "your-google-topic-name"
        }
      }
    },
    "example2": {
      "hostingType": "gcp",
      "gcp": {
        "functionName": "yourapp-test",
        "memory": 128,
        "trigger": {
          "type": "cloud.storage",
          "bucket": "your-google-bucket-name"
        }
      }
    }
  }
}

Similar to the previous example, update your package.json as follow:

"scripts": {
  "deploy:example1": "nowflow example1",
  "deploy:example2": "nowflow example2"
}

Then deploy using the same commands as in the previous section (e.g. npm run deploy:example1).

As promised, the code you will write in your index.js will be the same code you are used to writing for express apps:

const { app } = require('webfunc')

app.post((req, res) => {
  console.log(req)
  console.log(`Hello ${req.params.firstName}`)
})

eval(app.listen('app', 4000))

As for any webfunc app, the parameters passed the request will be in the req.params object.

IMPORTANT - ONLY USE 'post' OR 'all' METHODS FOR PUB/SUB AND STORAGE BASED FUNCTIONS

FAQ

What does webfunc use eval() to start the server?

You should have noticed that all the snippets above end up with eval(app.listen('app', 4000)). The main issue webfunc tackles is to serve endpoints using a uniform API regardless of the serverless hosting platform. This is indeed a challenge as different platforms use different convention. Zeit Now uses a standard Express server, which means that the api to start the server is similar to app.listen(). However, with FaaS (Google Cloud Functions, AWS Lambdas, ...), there is no server to be started. The server lifecycle is automatically managed by the 3rd party. The only piece of code you need to write is a handler function similar to exports.handler = (req, res) => res.status(200).send('Hello world'). In order to manage those 2 main scenarios, webfunc generate the code to be run as a string, and evaluate it using eval(). You can easily inspect the code as follow:

const { app } = require('webfunc')

app.get('/users/:username', (req, res) => res.status(200).send(`Hello ${req.params.username}`))

const code = app.listen('app', 4000)
console.log(eval(code))
eval(code)

To observe the difference between a hosting type "now" and "gcp", update the now.json file as follow:

{
  "environment": {
    "active": "default",
    "default": {
      "hostingType": "gcp"
    }
  }
}

Then run:

node index.js

Can I Use Webfunc In a Non-Serverless Environment?

Absolutely! If you don't specify a string as the first argument of the listen api, then it will work as an Express server:

const { app } = require('webfunc')

app.get('/users/:username', (req, res) => res.status(200).send(`Hello ${req.params.username}`))

app.listen(4000)

Then run:

node index.js

Annexes

A.1. CORS Refresher

COMING SOON...

A.2. CORS Basic Errors

WithCredentials & CORS The following configuration is forbidden:

const { cors } = require('webfunc')

const restrictedAccess = cors({
  origins: ['*'],
  credentials: true
})

You cannot allow anybody to access a resource("Access-Control-Allow-Origin": "*") while at the same time allowing anybody to share cookies("Access-Control-Allow-Credentials": "true"). This would be a huge security breach (i.e. CSRF attach).

For that reason, this configuration, though it allow your resource to be called from the same origin, would fail once your API is called from a different origin. A error similar to the following would be thrown by the browser: The value of the 'Access-Control-Allow-Origin' header in the response must not be the wildcard '*' when the request's credentials mode is 'include'.

Solutions

If you do need to share cookies, you will have to explicitely list the origins that are allowed to do so:

const { cors } = require('webfunc')

const restrictedAccess = cors({
  origins: ['http://your-allowed-origin.com'],
  credentials: true
})

If you do need to allow access to anybody, then do not allow requests to send cookies:

const { cors } = require('webfunc')

const restrictedAccess = cors({
  origins: ['*'],
  allowedHeaders: ['Authorization'],
  credentials: false
})

If you do need to pass authentication token, you will have to pass it using a special header(e.g. Authorization), or pass it in the query string if you want to avoid preflight queries (preflight queries happens in cross-origin requests when special headers are being used). However, passing credentials in the query string are considered a bad practice.

Contributing

npm test

This Is What We re Up To

We are Neap, an Australian Technology consultancy powering the startup ecosystem in Sydney. We simply love building Tech and also meeting new people, so don't hesitate to connect with us at https://neap.co.

Our other open-sourced projects:

Web Framework & Deployment Tools

webfunc: Write code for serverless similar to Express once, deploy everywhere.
now-flow: Automate your Zeit Now Deployments.

GraphQL

graphql-serverless: GraphQL (incl. a GraphiQL interface) middleware for webfunc.
schemaglue: Naturally breaks down your monolithic graphql schema into bits and pieces and then glue them back together.
graphql-s2s: Add GraphQL Schema support for type inheritance, generic typing, metadata decoration. Transpile the enriched GraphQL string schema into the standard string schema understood by graphql.js and the Apollo server client.
graphql-authorize: Authorization middleware for graphql-serverless. Add inline authorization straight into your GraphQl schema to restrict access to certain fields based on your user's rights.

React & React Native

react-native-game-engine: A lightweight game engine for react native.
react-native-game-engine-handbook: A React Native app showcasing some examples using react-native-game-engine.

Tools

aws-cloudwatch-logger: Promise based logger for AWS CloudWatch LogStream.

License

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
Neither the name of Neap Pty Ltd nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL NEAP PTY LTD BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

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WebFunc ·

Table of Contents

Install

Prerequisites

Install Webfunc

How To Use It

Basic - Build Once Deploy Everywhere

Passing Parameters To Your HTTP Endpoint

Webfunc Properties On The request Object

Deploying To Google Functions or AWS

Examples

Creating A REST API

Single Endpoint

Multiple Endpoints

Compatible With All Express Middleware

Using An Express Middleware Globally

Using An Express Middleware On a Specific Endpoint Only

Creating Your Own Middleware

Chaining Multiple Middleware On a Specific Endpoint

Managing Environment Variables Per Deployment

Intercepting The res.send() Method

Reacting To Google PubSub Topics

Intro

Minimum Message Requirement

Programmatically Publish To Google PubSub

Authentication

Uploading Files & Images

GraphQL

Configuration

CORS

Disabling Body Or Route Parsing

Customizing The req.params Property

Tips & Tricks

Dev - Easy Hot Reloading

Dev - Better Deployments With now-flow

Overview - Deploy To AWS, Add Google Pub/Sub Topic Trigger Based Functions & Automate Deployments

How To Use It

HTTPS Endpoints

Google Pub/Sub Topic & Storage Trigger Based Functions

FAQ

What does webfunc use eval() to start the server?

Can I Use Webfunc In a Non-Serverless Environment?

Annexes

A.1. CORS Refresher

A.2. CORS Basic Errors

Contributing

This Is What We re Up To

Web Framework & Deployment Tools

GraphQL

React & React Native

Tools

License

About

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