@serverless/serverless-components-a

Serverless Components A

Overview

This project is a prototype of a new concept Serverless has been exploring called "components". Our aim is to introduce highly configurable and composable pieces that allow for multi-cloud & third party resource use cases.

Components are capable of provisioning infrastructure while including both application logic AND lifecycle management. They have a focus on serverless/cloud resources and they also greatly enable reuse, sharing and simplicity.

Table of contents

• Getting started
• Concepts
  • Components
  • Serverless Registry
• Docs
  • aws-api-gateway-lambda-endpoint
  • aws-dynamodb-table
  • aws-iam-role
  • aws-lambda-function
  • github-webhook-receiver
  • util-aws-request
  • util-zipper

Getting started

Note: Please make sure that you've installed Node.js and have properly setup our AWS credentials.

1. Setup
   1. npm install --global @serverless/serverless-components-a
   2. Clone this repository
2. Configuring
   1. cd src/examples/github-webhook
   2. Open up the example in your favorite editor (e.g. atom .)
   3. Update the repository and githubToken parameters with your values
3. Deployment
   1. proto deploy
4. Testing
   1. proto test
5. Updating
   1. Change some parameters (e.g. the event or httpPath property)
   2. proto deploy
6. Removal
   1. proto remove

Concepts

Components

Components are a way to share and re-use pre-built functionality throughout different projects. A project can contain one or more components. Furthermore components can be wrapped and composed together to extend functionality.

Components take parameters as their input and compute outputs when run. One example use-case for an output is the .state.json file which is created for every project and holds state information for every single component used in the project.

Components can be defined in a serverless.yml file like this:

# serverless.yml
components:
  myDynamoDbTable:
    type: pmuens:aws-dynamodb-table@0.1.0
    parameters:
      attributeDefinitions:
        - attributeName: id
          attributeType: S
      keySchema:
        - attributeName: id
          keyType: HASH
      provisionedThroughput:
        readCapacityUnits: 1
        writeCapacityUnits: 1
      tableName: my-dynamodb-table

In this example we're using the aws-dynamodb-table component at version 0.1.0 which was authored by pmuens. We pass in different parameters to configure the infrastructure this component will setup. In our case we set the attributeDefinitions, the keySchame, the provisionedThroughput as well as the tableName.

Most components ship with sane defaults so that it's not necessary to provide all parameters.

A components underpinning functionality is provided by a function.

In this PoC implementation a function is equal to a component. This makes it possible to use components in a declarative way as well as through code.

The function which expresses the components functionality above looks like this:

// index.js
module.exports = (context, params, options) => {
  // destructuring the component parameters
  const {
    attributeDefinitions,
    keySchema,
    provisionedThroughput,
    tableName
  } = params

  // ...snip...

  async function createTable(tableName) {
    return sdk('DynamoDB', 'createTable', {
      TableName: tableName
    })
  }

  async function deleteTable(tableName) {
    return sdk('DynamoDB', 'deleteTable', {
      TableName: tableName
    })
  }

  // ...snip...

  // logic to setup the infrastructure
  async function deploy() {
    await createTable(params.tableName)
  }

  // logic to tear down the infrastructure
  async function remove() {
    await deleteTable(params.tableName)
  }

  // these functions are exposed and accessible through the CLI
  return {
    deploy,
    remove
  }
}

The components parameters and CLI options are passed in to the function and are accessible via params and options. The returned functions at the bottom of the function are exposed and accessible via CLI commands.

Treating a component and the corresponding function equally makes it possible to pull in pre-written components in code and therefore re-use them to write parent components which orchestrate different child components. Take a look at the code for the github-webhook-receiver component to see how existing components can be re-used in code.

Serverless Registry

The "Serverless Registry" is a core part in this implementation since it makes it possible to discover, publish and share existing components.

The registry is not only constrained to serve components. Since components are functions it's possible to wrap existing business logic into functions and publish them to the registry as well.

While implementing this prototype we've created two util functions / components called util-aws-request and util-zipper. Both are used in various components to steamline AWS SDK calls and .zip archive creation.

Looking into the future it could be possible to serve functions which are written in different languages through the registry.

Docs

aws-api-gateway-lambda-endpoint

Creates / Removes an API endpoint which is exposed via AWS API Gateway and connects directly to an AWS Lambda function.

Parameters

Name	Description	Type
path	The HTTP path	String
method	The HTTP method	String
lambdaArn	The AWS Lambda functions arn which should be connected via the API Gateway	String
roleArn	The role arn which is used to give the API Gateway the permission to call the AWS Lambda function	String

Example

type: pmuens:aws-api-gateway-lambda-endpoint@0.1.0
parameters:
  path: my-path
  method: GET
  lambdaArn: arn:aws:lambda:us-east-1:XXXXX:function:some-lambda-function
  roleArn: arn:aws:iam::XXXXX:role/some-api-gateway-role

aws-dynamodb-table

Creates / Removes an AWS DynamoDB table.

Parameters

Name	Description	Type
attributeDefinitions	The tables attribute definitions	Array
keySchema	The tables key schema	Array
provisionedThroughput	The tables provisioned throughput	Object
tableName	The tables name	String

Example

type: pmuens:aws-dynamodb-table@0.1.0
parameters:
  attributeDefinitions:
    - attributeName: id
      attributeType: S
  keySchema:
    - attributeName: id
      keyType: HASH
  provisionedThroughput:
    readCapacityUnits: 1
    writeCapacityUnits: 1
  tableName: my-dynamodb-table

aws-iam-role

Creates / Removes an AWS IAM role.

Parameters

Name	Description	Type
roleName	The name for the IAM role	String
service	The service the role targets	String
policyArn	The policy arn this role should assume	String

Example

type: pmuens:aws-iam-role@0.1.0
parameters:
  roleName: my-ec2-role
  service: ec2.amazonaws.com
  policyArn: arn:aws:iam::aws:policy/AdministratorAccess

aws-lambda-function

Creates / Removes an AWS Lambda function.

Parameters

Name	Description	Type
codeDirPath	Path to the location where the functions code is located	String
functionName	The functions name	String
handler	The functions handler	String
roleArn	The role arn the lambda should use	String
runtime	The functions runtime	String
environment	The functions environment variables	Object
memorySize	The functions memory size	Number
timeout	The functions timeout	Number

Example

type: pmuens:aws-lambda-function@0.1.0
parameters:
  codeDirPath: ./code
  functionName: my-lambda-function
  handler: index.handler
  roleArn: arn:aws:iam::XXXXX:role/some-lambda-role
  runtime: nodejs6.10
  environment:
    variables:
      foo: bar
  memorySize: 512
  timeout: 60

github-webhook-receiver

Creates / Removes a GitHub Webhook. Uses AWS as the cloud provider.

AWS resource names created by this component:

Resource	Name
Lambda function name	${name}-lambda-function
DynamoDB table name	${name}-logging-table
Lambda role name	${name}-role-lambda
API Gateway role name	${name}-role-api-gateway

Parameters

Name	Description	Type
name	The webhooks name (Note: this name will be used as a prefix for all AWS resources (see above))	String
codeDirPath	Path to the location where the functions code is located	String
httpPath	The HTTP path	String
repository	Name of the GitHub repository the Webhook should be created for	String
event	The Webhooks event	String
githubToken	The GitHub token which is used to create the Webhook on your behalf	String

Example

type: pmuens:github-webhook-receiver@0.1.0
parameters:
  name: my-github-webhook
  codeDirPath: ./code
  httpPath: webhook
  repository: jdoe/some-repo
  event: issue_comment
  githubToken: s0me3g1thu8t0k3n

util-aws-request

Helper which wraps the AWS SDK and provides some convenience functions.

Parameters

• None

Example

const request = loadFunction(context, 'pmuens:util-aws-request@0.1.0', params, options)

const res = await request.send('Lambda', 'deleteFunction', {
  FunctionName: params.functionName
})

util-zipper

Helper which provides functionality to create a .zip archive.

Parameters

• None

Example

const zipper = loadFunction(context, 'pmuens:util-zipper@0.1.0', params, options)

const artifactFilePath = await zipper.zip(codeDirPath, context.componentRootPath)