Serverless. Rainer Stropek. Web APIs. Serverless Web APIs. Saves the day. software architects gmbh

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1 Serverless Web APIs Rainer Stropek software architects gmbh Serverless Web APIs Web Mail Twitter Saves the day.

2 Your Host Rainer Stropek Developer, Entrepreneur MVP Microsoft Azure MVP Development Technologies MS Regional Director Senior Consultant IT-Visions Contact software architects gmbh

3 Agenda (German) Microservices schön und gut, aber Kunden wollen funktionierende Gesamtsysteme. Wenn ein Bug in VSTS angelegt wird, muss eine Message in Slack erscheinen und ein Task in der Zeiterfassung eingetragen werden. Wenn das Web-UI eine neue Bestellung meldet, muss jemand im SaaS-ERP den Produktionsauftrag generieren. Bis vor Kurzem übernahmen Worker-Prozesse/Container/Jobs diese Aufgabe. Jetzt lernt Azure neue Tricks: Azure Functions erlauben es, kleine Code-Stücke in der Cloud zu hosten, die durch Events wie HTTP-Requests, Queue-Einträge etc. gestartet werden. In Verbindung mit Webhooks und RESTful Web APIs wird die Integration verschiedener SaaS-Lösungen zu einem Gesamtsystem wesentlich erleichtert. In der Session stellt Rainer Stropek, langjähriger Azure MVP und MS Regional Director, Azure Functions vor, zeigt sie anhand einiger Demos und erklärt das Betriebs- und Preismodell.

4 What is Serverless? Aka Backend-as-a-Service or Function-as-a-Service Fully managed services Cloud is prerequisite See also Platform-as-a-Service (PaaS) Auto-scaling No explicit starting and stopping of VMs Done by the cloud provider automatically behind the scenes Billing not based on VM hours Abstract measures typically related to usage No usage no costs (aka scale down to zero) See also Wikipedia

5 Examples for FaaS Amazon Serverless Framework, AWS Lambda Supports Node.js, Python, Java (AWS FAQ) Microsoft Azure Functions (part of Azure App Service) Supports C#, F#, Node.js, Python, PHP, batch, bash, any executable (docs) Google Cloud Functions Supports Node.js (overview) Auth0 webtask Supports Node.js, C# (via Edge.js) (docs)

6 Classical Application Architecture Clients Servers Storage IaaS PaaS Reduced Operational Costs Control

7 Clients Auth Gateway Func 1 Func 2 Func Serverless High-level Architecture No servers but functions Pattern: Microservices Online editor or SCM integration Stateless (short-lived, ephemeral) Separate Auth service E.g. AAD, Google Auth API Gateway Routing, security External System Integration Hybrid solutions Event- or message-driven Webhooks (sync) Service bus, queues (async)

8 Patterns to Consider for FaaS Combine FaaS with PaaS solutions (standard and custom) Don t reinvent the wheel Examples: API Gateways, Search, RESTful web APIs from storage systems, etc. More logic on the client Especially compared to classical full-page-refresh web apps Higher-level functions using workflow engine Example: Azure Logic Apps Automate deployment using SCM integration Example: GitHub, VSTS

9 More about Webhooks Wikipedia Examples Visual Studio Team Services Microsoft Office 365 GitHub Docker Hub Jira Slack Zendesk Dropbox Twilio

10 Advantages and Challenges NoOps automation, managed service Reduce development costs Develop smaller components Reduce Operational costs No usage no costs Designed for Microservices Handles fluctuating load Auto-scaling Support many languages/platforms Best tool for the specific job High degree of freedom for teams Deployment is harder Automation is a necessity Handling of breaking changes Troubleshooting is more difficult System-wide logging and telemetry is important Limited control over configuration Gets better with containers Proliferation Guidelines for practices and patterns necessary Economy of scope Not made for long-running tasks Startup latency Further readings:

11 Azure Functions Fundamentals Create Function App Function App Settings Create Function SCM integration C#, Webhook Online Testing Function App settings Demo Trigger, Inputs, Outputs C#, Node.js HTTP, Service Bus Queues For more details see my GitHub repository

12 using System.Net; public static async Task<HttpResponseMessage> Run(HttpRequestMessage req, TraceWriter log) { log.info("received Tic Tac Toe request"); var board = await req.content.readasasync<string[]>(); if (board.length!= 9) { req.createresponse(httpstatuscode.badrequest, "No valid tic tac toe board"); HTTP Trigger C# Example for(var row = 0; row < 3; row ++) { if (!string.isnullorwhitespace(board[row * 3]) && board[row * 3] == board[row * 3 + 1] && board[row * 3] == board[row * 3 + 2]) { return BuildResponse(req, board[row * 3]); for(var column = 0; column < 3; column ++) { if (!string.isnullorwhitespace(board[column]) && board[column] == board[3 + column] && board[column] == board[2 * 3 + column]) { return BuildResponse(req, board[column]); if (!string.isnullorwhitespace(board[0]) && board[0] == board[3 + 1] && board[0] == board[2 * 3 + 2]) { return BuildResponse(req, board[0]); if (!string.isnullorwhitespace(board[2]) && board[2] == board[3 + 1] && board[2] == board[2 * 3]) { return BuildResponse(req, board[1]); return BuildResponse(req); private static HttpResponseMessage BuildResponse(HttpRequestMessage req, string winner = null) => req.createresponse(httpstatuscode.ok, (winner == null)? "No Winner" : $"Winner: {winner");

13 module.exports = function (context, req) { // Parse request body var board = JSON.parse(req.body); ; // Make sure that body is a properly formed array if (Array.isArray(board) && board.length == 9) { // Body is ok > send message to trigger analysis context.bindings.outputsbmsg = JSON.stringify({ Message: board ); // Send OK result to caller context.res = { status: 200 ; context.done(); else { // Body is malformed > send Bad Request to caller context.res = { status: 400, body: "No valid tic tac toe board" ; context.done(); HTTP Trigger Node.js Example Multiple Outputs Service Bus Queue HTTP

14 #r "Newtonsoft.Json" using System; using System.Threading.Tasks; using Newtonsoft.Json; public class BoardMessage { public string[] Message { get; set; Queue Trigger C# Example public static void Run(string boardmsg, TraceWriter log, out string outputsbmsg) { log.info("received Tic Tac Toe request"); var boardcontent = JsonConvert.DeserializeObject<BoardMessage>(boardMsg); var board = boardcontent.message; if (board == null board.length!= 9) { outputsbmsg = "No valid tic tac toe board"; return; for(var row = 0; row < 3; row ++) { if (!string.isnullorwhitespace(board[row * 3]) && board[row * 3] == board[row * 3 + 1] && board[row * 3] == board[row * 3 + 2]) { outputsbmsg = BuildResponse(board[row * 3]); return; [...] outputsbmsg = BuildResponse(); private static string BuildResponse(string winner = null) => (winner == null)? "No Winner" : $"Winner: {winner";

15 Scaling and Pricing Consumption plan Can run in other plans, too Price depends on: Memory Execution time Number of executions Quite high free grant Auto-scaling by Azure More about scaling:

16 Azure Functions Git Deployment Configure Local Git Repository Clone Azure Functions Repository Demo

17 Summary No Silver Bullet Is scalability necessary? We love it for jobs that run infrequently huge cost saver App is stateless Other PaaS services for storing state are necessary We often use it together with App Service Hybrid Connections for on-prem data stores Should be part of an overall Microservice strategy Guidelines and practices are necessary Great to combine with other PaaS services Self-made or existing ones

18 Serverless Web APIs Rainer Stropek software architects gmbh Q&A Thank your for coming! Mail Web Twitter Saves the day.