Global Azure Bootcamp 2017

Azure Functions

Agenda

• What is Azure Functions
• What can we build with Azure Functions
• How do we build Azure Functions
• How do we deploy Azure Functions
• Tips and tricks

Just ask questions along the way

About me

• + 15 years web developer (started with classic ASP)
• + 8 years professional Dev/Architect (.NET, SharePoint and Azure, first Azure cert in 2013)
• Working exclusively with Azure last 2.5 years 
• Managing Consultant @ Delegate A/S (MS Gold Partner)
• Lives in Malmö, Sweden
• Author of Lets Encrypt Site Extension for Azure Web Apps
• CTO at tiimo ApS 

mail@sjkp.dk

@simped

http://wp.sjkp.dk

DEMO

Getting started with Azure Functions

https://functions.azure.com/try

Typical Azure Function Scenarios

• Simple Backends
  • Web Backends, Mobile Backends, Bot Backends
• Data Processing
  • IoT, Image Processing, Data pipelines
• Maintenance tasks
  • Index Rebuild, Scheduled jobs  

What can we build with Azure Functions

• Code in
  • C#, F#, JavaScript (Bash, PHP, Python, PowerShell)
• Types of functions apps
  • Scheduled, Triggered, RunOnce, Proxies

Function Bindings

Azure Functions vs Web Jobs vs Microsoft Flow vs Logic Apps

Azure Functions Architecture

Service Plan

Web App

Func App 1

Func App 2

DEMO

Create a Function using the portal

Consumption Plan scaling

• Startup delay, up to 10 minute
• Max execution time per function job 5 min
• Scales up to 60 concurrent function job hosts
• Each function job host can run multiple function jobs

How to Develop with Visual Studio

• Azure SDK 2.9.3
• Visual Studio Function Tools
• Uses Azure Function CLI (node tools) for local debugging

DEMO

Develop a Azure Function with Visual Studio

Precompiled Functions

• Problems using the Web IDE (.csx)
  • No intelisense
  • Hard to maintain large code bases
  • Debugging -> Console.WriteLine (not cool)
• Precompiled functions
  • Fixes all of the above
  • We lose some simplicity/agility
• Conclusion
  • Portal is okay for prototypes 
  • Portal is okay for simple solutions
  • If you want a traditional .NET experience -> precompiled functions is your friend

Precompiled functions, how to

• Move the code to a .NET class library
• Add nuget (Microsoft.Azure.WebJobs.Extensions / Microsoft.Azure.WebJobs)
• Update function.json 

{
  "disabled": false,
  "scriptFile": "bin/SJKP.PrecompiledFunctions.dll",
  "entryPoint": "SJKP.PrecompiledFunctions.Functions.Run",
  "bindings": [
    {
      "authLevel": "function",
      "name": "req",
      "type": "httpTrigger",
      "direction": "in"
    },
    {
      "name": "res",
      "type": "http",
      "direction": "out"
    }
  ]
}

Creating an Azure Function Environment Using ARM Templates

{
  "$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "storageAccountType": {
      "type": "string",
      "defaultValue": "Standard_LRS",
      "allowedValues": [
        "Standard_LRS",
        "Standard_GRS",
        "Standard_ZRS",
        "Premium_LRS"
      ],
      "metadata": {
        "description": "Storage Account type"
      }
    },
    "functionAppName": {
      "type": "string",
      "defaultValue": "sjkptestfunction"
    },
    "functionAppDomainName": {
      "type": "string",
      "defaultValue": "myfunc.sjkp.dk"
    }
  },
  "variables": {
    "storageAccountName": "[concat('storage', uniqueString(resourceGroup().id))]",
    "dynamicAppServicePlanName": "[concat('dynamic', uniqueString(resourceGroup().id))]"
  },
  "resources": [
    {
      "type": "Microsoft.Storage/storageAccounts",
      "name": "[variables('storageAccountName')]",
      "apiVersion": "2015-06-15",
      "location": "[resourceGroup().location]",
      "properties": {
        "accountType": "[parameters('storageAccountType')]"
      }
    },
    {
      "type": "Microsoft.Web/serverfarms",
      "apiVersion": "2015-04-01",
      "name": "[variables('dynamicAppServicePlanName')]",
      "location": "[resourceGroup().location]",
      "properties": {
        "name": "[variables('dynamicAppServicePlanName')]",
        "computeMode": "Dynamic",
        "sku": "Dynamic"
      }
    },
    {
      "apiVersion": "2015-08-01",
      "type": "Microsoft.Web/sites",
      "name": "[parameters('functionAppName')]",
      "location": "[resourceGroup().location]",
      "kind": "functionapp",
      "properties": {
        "name": "[parameters('functionAppName')]",
        "serverFarmId": "[resourceId('Microsoft.Web/serverfarms', variables('dynamicAppServicePlanName'))]"
      },
      "dependsOn": [
        "[resourceId('Microsoft.Web/serverfarms', variables('dynamicAppServicePlanName'))]",
        "[resourceId('Microsoft.Storage/storageAccounts', variables('storageAccountName'))]"
      ],
      "resources": [
        {
          "apiVersion": "2015-08-01",
          "type": "hostNameBindings",
          "name": "[parameters('functionAppDomainName')]",
          "dependsOn": [
            "[concat('Microsoft.Web/sites/', parameters('functionAppName'))]"
          ],
          "tags": {
            "displayName": "hostNameBinding"
          },
          "properties": {
            "domainId": null,
            "hostNameType": "Verified",
            "siteName": "variables('webAppName')"
          }
        },
        {
          "apiVersion": "2016-03-01",
          "name": "appsettings",
          "type": "config",
          "dependsOn": [
            "[resourceId('Microsoft.Web/sites', parameters('functionAppName'))]",
            "[resourceId('Microsoft.Storage/storageAccounts', variables('storageAccountName'))]"
          ],
          "properties": {
            "AzureWebJobsStorage": "[concat('DefaultEndpointsProtocol=https;AccountName=',variables('storageAccountName'),';AccountKey=',listkeys(resourceId('Microsoft.Storage/storageAccounts', variables('storageAccountName')), '2015-05-01-preview').key1,';')]",
            "AzureWebJobsDashboard": "[concat('DefaultEndpointsProtocol=https;AccountName=',variables('storageAccountName'),';AccountKey=',listkeys(resourceId('Microsoft.Storage/storageAccounts', variables('storageAccountName')), '2015-05-01-preview').key1,';')]",
            "WEBSITE_CONTENTAZUREFILECONNECTIONSTRING": "[concat('DefaultEndpointsProtocol=https;AccountName=',variables('storageAccountName'),';AccountKey=',listkeys(resourceId('Microsoft.Storage/storageAccounts', variables('storageAccountName')), '2015-05-01-preview').key1,';')]",
            "WEBSITE_CONTENTSHARE": "[parameters('functionAppName')]",
            "FUNCTIONS_EXTENSION_VERSION": "latest",
            "ROUTING_EXTENSION_VERSION": "~0.2"
          }
        },
        {
          "apiVersion": "2015-08-01",
          "name": "TestFunction",
          "type": "functions",
          "dependsOn": [
            "[resourceId('Microsoft.Web/sites', parameters('functionAppName'))]"
          ],
          "properties": {
            "config": {
              "bindings": [
                {
                  "authLevel": "anonymous",
                  "name": "req",
                  "type": "httpTrigger",
                  "direction": "in"
                },
                {
                  "name": "res",
                  "type": "http",
                  "direction": "out"
                }
              ]
            },
            "files": {
              "run.csx": "using System.Net;\r\npublic static async Task<HttpResponseMessage> Run(HttpRequestMessage req, TraceWriter log)\r\n{\r\n    log.Info($\"C# HTTP trigger function processed a request. RequestUri={req.RequestUri}\");\r\n\r\n    // parse query parameter\r\n    string name = req.GetQueryNameValuePairs()\r\n        .FirstOrDefault(q => string.Compare(q.Key, \"name\", true) == 0)\r\n        .Value;\r\n\r\n    // Get request body\r\n    dynamic data = await req.Content.ReadAsAsync<object>();\r\n\r\n    // Set name to query string or body data\r\n    name = name ?? data?.name;\r\n\r\n    return name == null\r\n        ? req.CreateResponse(HttpStatusCode.BadRequest, \"Please pass a name on the query string or in the request body\")\r\n        : req.CreateResponse(HttpStatusCode.OK, \"Hello \" + name);\r\n}"
            }
          }
        }
      ]
    }
  ],
  "outputs": { }
}

source

ARM template more info

• Same as the when deploying web apps
• Remember to set App Settings for storage account
• Both dynamic and standard app service plan can be used
• It is possible to deploy files into the function by embedding them in the template
• It is also possible to assign custom host names (Requires DNS is setup)

Tips and Tricks

Nothing Runs Forever

• Max run time for a dynamic function 5 mins
• 5 seconds to clean up -> termination
• Use cancellationtoken if you need to do things on shutdown

using System;
using System.Threading;

public static async Task Run(string input, TraceWriter log, CancellationToken cancel)
{
    log.Info($"C# manually triggered function called with input: {input}");
    do {
        log.Info($"Output {DateTime.Now}");
        await Task.Delay(2500);
    } while(!cancel.IsCancellationRequested);    
    log.Info($"stopping: {cancel.IsCancellationRequested}");
}

The KUDU portal

https://[function-app-name].scm.azurewebsites.net

App Service Editor aka Monaco

Execution Context

• Get the name of the specific instance

using System.Net;

public static async Task<HttpResponseMessage> Run(HttpRequestMessage req, ExecutionContext ctx, TraceWriter log)
{
    log.Info($"C# HTTP trigger invocationId: {ctx.InvocationId}");

    return req.CreateResponse(HttpStatusCode.OK, "ctx.InvocationId");
}

Application Insights

• First class support for application insights is comming (it is in beta)
  • Add App Setting – APPINSIGHTS_INSTRUMENTATIONKEY =  {Instrumentation Key}
  • Change the App Setting FUNCTIONS_EXTENSION_VERSION to beta
• Standard .net diagnostics logging can be used (same as web apps)
• TraceWriter for debugging 
• Monitoring tab, only last 20 executions
• To manually setup application insights, treat the function as a console app
  • Configure application insights in code
  • Ensure to flush to application insight on termination

Proxies

• Light weight alternative to API Management
• Bind many functions apps together under one common API
• Use it for trickery, rewrite GET to POST etc, reverse proxy, add headers
• It is just a proxies.json file in the wwwroot 
• The schema http://json.schemastore.org/proxies.json
• Some examples: http://wp.sjkp.dk/use-azure-functions-as-a-proxy/

Where to get help

• User voice 
• Github
• Stackoverflow

Thank you for your time!

https://github.com/sjkp/AzureBootcamp2017.Functions

Hands On Laps - Beginners

https://github.com/Microsoft/TechnicalCommunityContent/tree/master/Cloud%20Computing/Azure%20Functions