PoC - Serverless Toolkit CLI

• Setup
• Concepts

Setup

1. Install dependencies

yarn

1. Create Saga with initial state

yarn:create

4. Restore state -> apply command -> save "new" state

yarn:update
yarn:update-increment
yarn:update-decrement

5. Deploy using Lambda Function-URL

yarn deploy

Todos

• upgrade to AWS-CDK v2.x
• docs hosted zone / optional domain name
• add cdk app script to app root (stk init)

Concepts

Instance Management

• list sagas by type using the CLI
• create and destory saga by id using the CLI
• correlation/instance ID can be client generated, using UUID by default

SDK

• import { bindings, alarm, credentials, expire, store, worker } from 'gusto-sdk'

Bindings

• defines the local handler for external events e.g. bindings.ses['contact@example.com'].on('inbound').bind(this.onInbound)

examples

export default class Counter {
    constructur() {
        Counter.addBinding(bindings.ses.onInbound('contact@example.com').bind(this.onEmail))
    }
}

export default function counter() {
    doSomething.addBinding(bindings.ses.onInbound('contact@example.com'))
}

Communication

• using a HTTP based API
• external events as trigger (e.g. SES, Event-Bridge, Shopify, etc.) via Bindings from our SDK

Worker execution

• default execution timeout is 15 Minutes
• concurrent execution is 1000
• maximum memory size is 128MB
• request response invocation
• e.g. chaining via const response = await worker.invoke('other')

Saga execution

• default execution timeout is 1 Minute
• concurrent execution is 1 per Saga type
• maximum memory size is 128MB
• async invocation using an event queue (unordered, at-least-once)

Saga persistent state

• every public property is persistent
• the maximum serialized size of a persistent property is 400kb

KV Store

• available via store
• list, get, set and remove operations to query and modify states
• handle changes using onChange handler attached to DynamoDB change stream

Commands

• the command handler is a function of the Saga and has the same name as the command
• command handler invocation via command property
• command arguments via commandArgs property

Alarms

• invocation at a specific time
• handle alarm using onAlarm
• alarm - set, clear

Security

• 3rd party code execution is dynamically loaded from S3 and sandboxed in VM2
• credential KV store is available via credentials
• credential KV store management via CLI

Saga expiry

• default expiry is 1 year
• reschedule possible
• handle expiry using onExpire
• expire - at

Page objects

• Svelte and Markdown based Server Side Rendering