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September 20, 2021 11:57 pm GMT

a first look at graphQL helix

GraphQL Helix is a framework and runtime agnostic collection of utility functions for building your own GraphQL HTTP server. Instead of providing a complete HTTP server or middleware plugin function, GraphQL Helix only provides a handful of functions for turning an HTTP request into a GraphQL execution result. You decide how to send back the response.

Outline

Motivations and API

Daniel Rearden listed the following reasons pushing him to create Helix, believing that these factors were absent from popular solutions like Apollo Server, express-graphql and Mercurius:

  • Wanted bleeding-edge GraphQL features like @defer, @stream and @live directives.
  • Wanted to not be tied down to a specific framework or runtime environment.
  • Wanted control over how server features like persisted queries were implemented.
  • Wanted something other than WebSockets (i.e. SSE) for subscriptions.

renderGraphiQL and shouldRenderGraphiQL

renderGraphiQL returns the HTML to render a GraphiQL instance. shouldRenderGraphiQL uses the method and headers in the request to determine whether a GraphiQL instance should be returned instead of processing an API request.

getGraphQLParameters

getGraphQLParameters extracts the GraphQL parameters from the request including the query, variables and operationName values.

processRequest

processRequest takes the schema, request, query, variables, operationName and a number of other optional parameters and returns one of three kinds of results, depending on how the server should respond:

  1. RESPONSE - regular JSON payload
  2. MULTIPART RESPONSE - multipart response (when @stream or @defer directives are used)
  3. PUSH - stream of events to push back down the client for a subscription

Serve GraphQL Helix Locally

mkdir ajcwebdev-graphql-helixcd ajcwebdev-graphql-helixyarn init -yyarn add express graphql-helix graphqltouch index.jsecho 'node_modules
.DS_Store' > .gitignore

index.js

// index.jsconst express = require("express")const {  getGraphQLParameters,  processRequest,  renderGraphiQL,  shouldRenderGraphiQL,} = require("graphql-helix")const {  GraphQLObjectType,  GraphQLSchema,  GraphQLString,} = require("graphql")const schema = new GraphQLSchema({  query: new GraphQLObjectType({    name: "Query",    fields: () => ({      hello: {        type: GraphQLString,        resolve: () => "Hello from GraphQL Helix!",      }    }),  }),})const app = express()app.use(express.json())app.use("/graphql", async (req, res) => {  const request = {    body: req.body,    headers: req.headers,    method: req.method,    query: req.query,  }  if (shouldRenderGraphiQL(request)) {    res.send(renderGraphiQL())  }  else {    const {      operationName,      query,      variables    } = getGraphQLParameters(request)    const result = await processRequest({      operationName,      query,      variables,      request,      schema,    })    if (result.type === "RESPONSE") {      result.headers.forEach((        { name, value }      ) => res.setHeader(name, value))      res.status(result.status)      res.json(result.payload)    }  }})const port = process.env.PORT || 4000app.listen(port, () => {  console.log(`GraphQL server is running on port ${port}.`)})

Run test queries on GraphQL Helix Locally

Start the server with node index.js.

node index.js

Open localhost:4000/graphql and send a hello query.

query HELLO_QUERY { hello }

01-graphql-helix-localhost-4000

curl --request POST \  --url http://localhost:4000/graphql \  --header 'content-type: application/json' \  --data '{"query":"{ hello }"}'

GraphQL Helix Final Project Structure

 .gitignore index.js package.json

Deploy GraphQL Helix with Serverless Framework

The Serverless Framework is an open source framework for building applications on AWS Lambda. It provides a CLI for developing and deploying AWS Lambda functions, along with the AWS infrastructure resources they require.

mkdir graphql-helix-serverlesscd graphql-helix-serverlessyarn init -yyarn add express graphql-helix graphql serverless-httptouch index.js serverless.ymlecho 'node_modules
.DS_Store
.serverless' > .gitignore

index.js

The serverless-http package is a piece of middleware that handles the interface between Node applications and the specifics of API Gateway. It allows you to wrap your API for serverless use without needing an HTTP server, port, or socket.

// index.jsconst serverless = require('serverless-http')const express = require("express")const {  getGraphQLParameters,  processRequest,  renderGraphiQL,  shouldRenderGraphiQL,} = require("graphql-helix")const {  GraphQLObjectType,  GraphQLSchema,  GraphQLString,} = require("graphql")const schema = new GraphQLSchema({  query: new GraphQLObjectType({    name: "Query",    fields: () => ({      hello: {        type: GraphQLString,        resolve: () => "Hello from GraphQL Helix on Serverless!",      }    }),  }),})const app = express()app.use(express.json())app.use("/graphql", async (req, res) => {  const request = {    body: req.body,    headers: req.headers,    method: req.method,    query: req.query,  }  if (shouldRenderGraphiQL(request)) {    res.send(renderGraphiQL())  }  else {    const {      operationName,      query,      variables    } = getGraphQLParameters(request)    const result = await processRequest({      operationName,      query,      variables,      request,      schema,    })    if (result.type === "RESPONSE") {      result.headers.forEach((        { name, value }      ) => res.setHeader(name, value))      res.status(result.status)      res.json(result.payload)    }  }})const handler = serverless(app)module.exports.start = async (event, context) => {  const result = await handler(event, context)  return result}

serverless.yml

The resources and functions are defined in a file called serverless.yml which includes:

  • The provider for the Node runtime and AWS region
  • The handler and events for your functions.
# serverless.ymlservice: ajcwebdev-graphql-helix-expressframeworkVersion: '2'provider:  name: aws  stage: dev  runtime: nodejs14.x  versionFunctions: false  lambdaHashingVersion: 20201221  httpApi:    cors:      allowedOrigins:        - '*'      allowedMethods:        - GET        - POST        - HEAD      allowedHeaders:        - Accept        - Authorization        - Content-Typefunctions:  endpoint:    handler: index.start    events:      - httpApi:          path: '*'          method: '*'

The handler is named index.start because it is formatted as <FILENAME>.<HANDLER>.

Upload to AWS with sls deploy

Once the project is defined in code it can be deployed with the sls deploy command. This command creates a CloudFormation stack defining any necessary resources such as API gateways or S3 buckets.

sls deploy --verbose
service: ajcwebdev-graphql-helix-expressstage: devregion: us-east-1stack: ajcwebdev-graphql-helix-express-devresources: 10api keys:  Noneendpoints:  ANY - https://cuml5hnx0b.execute-api.us-east-1.amazonaws.comfunctions:  endpoint: ajcwebdev-graphql-helix-express-dev-endpointlayers:  None

Run test queries on GraphQL Helix Serverless

Open cuml5hnx0b.execute-api.us-east-1.amazonaws.com/graphql and send a hello query.

query HELLO_QUERY { hello }

02-graphql-helix-serverless-framework

curl --request POST \  --url https://cuml5hnx0b.execute-api.us-east-1.amazonaws.com/graphql \  --header 'content-type: application/json' \  --data '{"query":"{ hello }"}'

GraphQL Helix Serverless Final Project Structure

 .gitignore index.js package.json serverless.yml yarn.lock

Deploy GraphQL Helix with Amplify

AWS Amplify is a set of tools and services to help frontend web and mobile developers build fullstack applications with AWS infrastructure. It includes a CLI for creating and deploying CloudFormation stacks along with a Console and Admin UI for managing frontend web apps, backend environments, CI/CD, and user data.

mkdir graphql-helix-amplifycd graphql-helix-amplifyamplify init

The amplify init command creates a boilerplate project that is setup for generating CloudFormation templates.

? Enter a name for the project ajcwebdevhelixThe following configuration will be applied:Project information| Name: ajcwebdevhelix| Environment: dev| Default editor: Visual Studio Code| App type: javascript| Javascript framework: none| Source Directory Path: src| Distribution Directory Path: dist| Build Command: npm run-script build| Start Command: npm run-script start? Initialize the project with the above configuration? YesUsing default provider  awscloudformation? Select the authentication method you want to use: AWS profileFor more information on AWS Profiles, see:https://docs.aws.amazon.com/cli/latest/userguide/cli-configure-profiles.html? Please choose the profile you want to use default

Create backend with amplify add api

amplify add api configures a Lambda handler and API gateway to serve the function.

amplify add api
? Please select from one of the below mentioned services: REST? Provide a friendly name for your resource to be used as a label for this category in the project: helixresource? Provide a path (e.g., /items): /graphql? Choose a Lambda source: Create a new Lambda function? Provide the AWS Lambda function name: helixfunction? Choose the function runtime that you want to use: NodeJS? Choose the function template that you want to use: Hello World? Do you want to access other resources created in this project from your Lambda function? N? Do you want to edit the local lambda function now? N? Restrict API access: N? Do you want to add another path? N
cd amplify/backend/function/helixfunction/srcyarn add graphql-helix graphql express serverless-httpcd ../../../../../

index.js

// amplify/backend/function/helixfunction/src/index.jsconst serverless = require('serverless-http')const express = require("express")const {  getGraphQLParameters,  processRequest,  renderGraphiQL,  shouldRenderGraphiQL,} = require("graphql-helix")const {  GraphQLObjectType,  GraphQLSchema,  GraphQLString,} = require("graphql")const schema = new GraphQLSchema({  query: new GraphQLObjectType({    name: "Query",    fields: () => ({      hello: {        type: GraphQLString,        resolve: () => "Hello from GraphQL Helix on Amplify!",      }    }),  }),})const app = express()app.use(express.json())app.use("/graphql", async (req, res) => {  const request = {    body: req.body,    headers: req.headers,    method: req.method,    query: req.query,  }  if (shouldRenderGraphiQL(request)) {    res.send(renderGraphiQL())  }  else {    const {      operationName,      query,      variables    } = getGraphQLParameters(request)    const result = await processRequest({      operationName,      query,      variables,      request,      schema,    })    if (result.type === "RESPONSE") {      result.headers.forEach((        { name, value }      ) => res.setHeader(name, value))      res.status(result.status)      res.json(result.payload)    }  }})module.exports.handler = serverless(app)

Upload to AWS with amplify push

amplify push uploads the stack templates to an S3 bucket and calls the CloudFormation API to create or update resources in the cloud.

amplify push
 Successfully pulled backend environment dev from the cloud.    Current Environment: dev Category  Resource name  Operation  Provider plugin    Function  helixfunction  Create     awscloudformation  Api       helixresource  Create     awscloudformation ? Are you sure you want to continue? YesREST API endpoint: https://acj63jadzb.execute-api.us-west-1.amazonaws.com/dev

Run test queries on GraphQL Helix Amplify

Open acj63jadzb.execute-api.us-west-1.amazonaws.com/dev/graphql and send a hello query.

query HELLO_QUERY { hello }

03-graphql-helix-amplify

curl --request POST \  --url https://acj63jadzb.execute-api.us-west-1.amazonaws.com/dev/graphql \  --header 'content-type: application/json' \  --data '{"query":"{ hello }"}'

GraphQL Helix Amplify Final Project Structure

 .gitignore amplify     backend         api            helixresource                api-params.json                helixresource-cloudformation-template.json                parameters.json         function             helixfunction                 function-parameters.json                 helixfunction-cloudformation-template.json                 src                     event.json                     index.js                     package.json                     yarn.lock

Deploy GraphQL Helix with Docker and Fly

Fly is a platform for full stack applications and databases that need to run globally. Fly executes your code close to users and scales compute in cities where your app is busiest. You can run arbitrary Docker containers and host popular databases like Postgres.

mkdir graphql-helix-dockercd graphql-helix-dockernpm init -ynpm i express graphql-helix graphqltouch index.js Dockerfile .dockerignore docker-compose.ymlecho 'node_modules
.DS_Store' > .gitignore

index.js

// index.jsconst express = require("express")const {  getGraphQLParameters,  processRequest,  renderGraphiQL,  shouldRenderGraphiQL,} = require("graphql-helix")const {  GraphQLObjectType,  GraphQLSchema,  GraphQLString,} = require("graphql")const schema = new GraphQLSchema({  query: new GraphQLObjectType({    name: "Query",    fields: () => ({      hello: {        type: GraphQLString,        resolve: () => "Hello from GraphQL Helix on Docker!",      }    }),  }),})const app = express()app.use(express.json())app.use("/graphql", async (req, res) => {  const request = {    body: req.body,    headers: req.headers,    method: req.method,    query: req.query,  }  if (shouldRenderGraphiQL(request)) {    res.send(renderGraphiQL())  }  else {    const {      operationName,      query,      variables    } = getGraphQLParameters(request)    const result = await processRequest({      operationName,      query,      variables,      request,      schema,    })    if (result.type === "RESPONSE") {      result.headers.forEach((        { name, value }      ) => res.setHeader(name, value))      res.status(result.status)      res.json(result.payload)    }  }})const port = process.env.PORT || 8080app.listen(port, () => {  console.log(`GraphQL server is running on port ${port}.`)})

Dockerfile

Docker can build images automatically by reading the instructions from a Dockerfile. A Dockerfile is a text document that contains all the commands a user could call on the command line to assemble an image.

FROM node:14-alpineLABEL org.opencontainers.image.source https://github.com/ajcwebdev/graphql-helix-dockerWORKDIR /usr/src/appCOPY package*.json ./RUN npm iCOPY . ./EXPOSE 8080CMD [ "node", "index.js" ]

For a more in depth explanation of these commands, see my previous article, A First Look at Docker.

.dockerignore

Before the docker CLI sends the context to the docker daemon, it looks for a file named .dockerignore in the root directory of the context.

node_modulesDockerfile.dockerignore.git.gitignorenpm-debug.log

If this file exists, the CLI modifies the context to exclude files and directories that match patterns in it. This helps avoid sending large or sensitive files and directories to the daemon.

docker-compose.yml

Compose is a tool for defining and running multi-container Docker applications. After configuring your applications services with a YAML file, you can create and start all your services with a single command.

version: "3.9"services:  web:    build: .    ports:      - "49160:8080"

Run test queries on GraphQL Helix Docker

The docker compose up command aggregates the output of each container. It builds, (re)creates, starts, and attaches to containers for a service.

docker compose up
Attaching to web_1web_1  | GraphQL server is running on port 8080.

To test your app, get the port of your app that Docker mapped:

docker ps

Docker mapped the 8080 port inside of the container to the port 49160 on your machine.

CONTAINER ID50935f5f4ae6IMAGEgraphql-helix-docker_webCOMMAND"docker-entrypoint.s"CREATED47 seconds agoSTATUSUp 46 secondsPORTS0.0.0.0:49160->8080/tcp, :::49160->8080/tcpNAMESgraphql-helix-docker_web_1

Open localhost:49160/graphql and send a hello query.

query HELLO_QUERY { hello }

04-graphql-helix-docker

curl --request POST \  --url http://localhost:49160/graphql \  --header 'content-type: application/json' \  --data '{"query":"{ hello }"}'

Launch app on Fly with fly launch

Run fly launch in the directory with your source code to configure your app for deployment.

fly launch \  --name graphql-helix-docker \  --region sjc

This will create and configure a fly app by inspecting your source code and prompting you to deploy.

Creating app in /Users/ajcwebdev/graphql-helix-dockerScanning source codeDetected Dockerfile appAutomatically selected personal organization: Anthony CampoloCreated app graphql-helix-docker in organization personalWrote config file fly.tomlYour app is ready. Deploy with `flyctl deploy`? Would you like to deploy now? No

Open fly.toml and add the following PORT number under env.

[env]  PORT = 8080

Deploy application with fly deploy

fly deploy
Image: registry.fly.io/graphql-helix-docker:deployment-1631689218Image size: 124 MB==> Creating releaseRelease v2 createdYou can detach the terminal anytime without stopping the deploymentMonitoring Deployment1 desired, 1 placed, 1 healthy, 0 unhealthy [health checks: 1 total, 1 passing]--> v0 deployed successfully

Check the application's status with fly status.

fly status
App  Name     = graphql-helix-docker            Owner    = personal                        Version  = 0                               Status   = running                         Hostname = graphql-helix-docker.fly.dev  Deployment Status  ID          = 47cb82b9-aaf1-5ee8-df1b-b4f10e389f16           Version     = v0                                             Status      = successful                                     Description = Deployment completed successfully              Instances   = 1 desired, 1 placed, 1 healthy, 0 unhealthy  InstancesID       TASK VERSION REGION DESIRED STATUS  HEALTH CHECKS      RESTARTS CREATED   a8d02b87 app  0       sjc    run     running 1 total, 1 passing 0        4m28s ago

Run test queries on GraphQL Helix Docker Fly

Open graphql-helix-docker.fly.dev/graphql and send a hello query.

query HELLO_QUERY { hello }

05-graphql-helix-docker-fly

curl --request POST \  --url https://graphql-helix-docker.fly.dev/graphql \  --header 'content-type: application/json' \  --data '{"query":"{ hello }"}'

GraphQL Helix Docker Final Project Structure

 .dockerignore .gitignore docker-compose.yml Dockerfile fly.toml index.js package.json

Resources

Building a GraphQL server with GraphQL Helix provides a comprehensive description of GraphQL Helix's implementation. The examples folder in the graphql-helix repo also includes example applications such as:


Original Link: https://dev.to/ajcwebdev/a-first-look-at-graphql-helix-1db3

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