Serverless Microservices are the New Black

Serverless Microservices Are The New Black   Lorna Mitchell, IBM

Serverless FaaS: Functions as a Service  write a function (many languages supported)  deploy it to the cloud (Lambda, Cloud Functions, etc)  only pay while the function is running (charged per GBsec)  your platform scales on demand @lornajane

When To Go Serverless  To create a small, scalable application (focussed API, microservices)  For occasional server needs (contact form on static site)  To provide compute power (processing quantities of data)  To move heavy lifting off web platform (classic example: PDF generation) @lornajane

FaaS + HTTP = Microservices! @lornajane

Microservices Microservices are:  small and modular  loosely coupled  independently developed and deployed  great for building components  decentralised   ... they are basically small HTTP APIs @lornajane

Microservice Design Points I prefer RESTful-ish APIs  Status codes are important  Headers are for metadata  URLs and verbs together define what happens  All endpoints are stateless  SSL is required @lornajane

Lorna's Plans Service Keep a list of my travel plans, with locations and dates.   Use a serverless platform (IBM Cloud Functions) and PostgreSQL GET   /plans list all plans GET   /plans/42 show one plan POST   /plans create a new plan DELETE   /plans/42 delete a plan @lornajane

Lorna's Plans Service @lornajane

Creating the Microservices     @lornajane

Creating the Microservices     @lornajane

Writing Serverless Functions  Small, self-contained units of functionality  Run on-demand in response to an event  Incoming parameters can include  event information  parameters set at deploy time  connection info for other services @lornajane

Make Plans: the Code 1 const

pgp

=

require ( 'pg-promise' )(); 2 function

main ( params )

{ 3

var

postgres_url

=

params [ '__bx_creds' ][ 'compose-for-postgresql' ][ 'uri' ]; 4

var

base_url

=

params [ '__ow_headers' ][ 'x-forwarded-url' ]; 5

return

new

Promise ( function ( resolve ,

reject )

{ 6

db

=

pgp ( postgres_url ,

[]); 7 8

db . one ( "INSERT INTO plans (location, travel_date) VALUES 9 ($1, $2) RETURNING plan_id" , 10

[ location ,

travel_date ]) 11

. then ( function ( data )

{ 12

var

redirect_to

=

base_url

"/"

data . plan_id ; 13

resolve ({ headers :

{ "Location" :

redirect_to }, 14

statusCode :

303 }) 15

}) @lornajane

Prepare to Deploy: package In OpenWhisk, there are "packages". These let us:  group actions together  add parameters to a package that will be available to all actions   From the deployment script, the line to create plans-api :   ibmcloud wsk package update plans-api @lornajane

Prepare to Deploy: services The function needs to connect to the database. We can bind the database to the package to achieve this:   ibmcloud wsk service bind compose-for-postgresql plans-api @lornajane

Prepare to Deploy: libraries To include extra libraries, we can:  create package.json and run npm   install  zip up index.js and node_modules into a zip file  deploy the zip file, and include runtime instructions   cd write-plan zip -rq write-plan.zip index.js node_modules @lornajane

Make Plans: Deploy We're ready! Push the action to the cloud:   ibmcloud wsk action update --kind nodejs:8 --web raw
plans-api/write-plan write-plan.zip @lornajane

Make Plans: API Gateway To have this action repsond to our HTTP request, set up the API Gateway:  create the API  set up the path, verb and action to link together   ibmcloud wsk api create /plans GET plans-api/get-plans
--response-type http @lornajane

Creating the Microservices     @lornajane

Calling The Endpoint Quick example with cURL (other clients available):   $ curl -L -H "Content-Type: application/json"
https://service.eu.apiconnect.ibmcloud.com/.../plans
-d '{"location": "Turin", "travel_date": "2018-04-11"}' { "plans": [{ "plan_id": 3, "travel_date": "2018-04-11T00:00:00.000Z", "location": "Turin" }] } @lornajane

Microservices: Security @lornajane

Security In web console: https://console.bluemix.net/openwhisk/apimanagement @lornajane

Security In web console: https://console.bluemix.net/openwhisk/apimanagement @lornajane

Project Structure Many possible approaches, this is mine: . ├── deploy.sh ├── get-plans │   ├── index.js │   ├── node_modules │   ├── package-lock.json │   └── package.json └── write-plan ├── index.js ├── node_modules ├── package-lock.json └── package.json @lornajane

Deployment Using https://travis-ci.com/  deploy with a script  script downloads ibmcloud tool and cloud-functions plugin  set an API key as an environment variable  then run commands (see deploy.sh in GitHub project) @lornajane

Serverless Microservices @lornajane

Serverless Ideal for working with many small parts   Apache OpenWhisk paired with API Gateway: perfect candidate for microservices @lornajane

Microservices Service Oriented Architecture is alive and well  microservices expose endpoints  they share reusable components  specific components guard access to services/datastores  each component can be separately developed, tested and deployed @lornajane

Resources  Code: https://github.com/lornajane/plans-microservice  Apache OpenWhisk: http://openwhisk.apache.org  IBM Cloud Functions: https://www.ibm.com/cloud/functions  My blog: https://lornajane.net @lornajane