Azure Functions offer server-less cloud services and are the next evolution in distributed computing and hosting after containers. Join this session to learn how to develop Azure Functions using C# and .NET, and how to test, build and deploy to Azure. We will cover .NET programming details, architecture, internals and hosting. Also, you will learn how to set up a local development environment to build and host locally. After this session you are ready to design and create state of the art Azure Functions using .NET

1. 1
Server-less compute with
.NET based Azure Functions
Alex Thissen
Cloud architect at Xpirit, The Netherlands
@alexthissen

2. 2
Programming
Functions
Introducing
Azure Functions
Serverless
architectures
Debugging
and testing
Going to
production
Wrapup

3. 3
Server-less architectures and Azure Functions

4. 4
There are no servers…
When you do not need them

5. 5
Servers and compute
Available when you need it

6. 6
Event-driven
Responds to external triggers
Instant scaling
Abstraction of server infrastructure
Scales when needed
Pay by consumption
Charged by sub-second units of compute

7. 7

8. 8

9. 9
Stores in Blob storage Produces scaled images

10. 10
Azure
Functions
101

11. 11
Scripts
Azure Portal or Visual Studio Code
.NET with C#
Visual Studio 2017
Instant feedback and testing
Less control
Azure tooling generates metadata files
Integrates with
source control
1 2
Achieve higher code quality
Compilation and code analysis
Unit testing
Combine in
CI/CD pipelines

12. 12
http://github.com/Azure/Azure-Functions

13. 13

14. 14
Function apps
• Hosted as Azure App Service
• JSON based configuration
• Running (multiple) functions
Trigger starts execution
Bindings for
input and output
Zero or more possible
Triggers and bindings can vary
per function

15. 15
Demo
Creating and using Azure Functions

16. 16
Developing Azure Functions
with .NET and Visual Studio

17. 17

18. 18

19. 19
[FunctionName("HelloWorldFunction")]
public static HttpResponseMessage Run(
[HttpTrigger] HttpRequestMessage req,
TraceWriter log)
{
log.Info("C# HTTP trigger function processed a request.");
return req.CreateResponse(HttpStatusCode.OK, "Hello, World!");
}
Defines what this function
is triggered by

20. 20
[FunctionName("ImageAnalyzer")]
[return: Queue("AnalysisResults", Connection="…")]
public static string Run(
[QueueTrigger("ImagesToAnalyze", Connection="…")] string imageName,
[Blob("images/{queueTrigger}",
FileAccess.Read,
Connection = "…")] Stream blob, TraceWriter log) {
return ...;
}
Connection property refers
to value from application
settings
Attribute values can refer to
trigger metadata with { }

21. 21

22. 22
Demo
Programming Azure Functions
with Visual Studio 2017

23. 23
[FunctionName("ValidateBlobSize")]
public static void Run(
[QueueTrigger("ImagesInput",
Connection = "…")] string blobNameInQueue,
[Blob("images/{queueTrigger}",
FileAccess.Read,
Connection = "…")] Stream blob,
TraceWriter log) { // Your function code …
}

24. 24
[FunctionName("FunctionQueueTrigger")]
public static void Run(
[QueueTrigger("imagesinput", Connection = "…")]string blobNameInQueue,
[Blob("images/{queueTrigger}", FileAccess.Read, Connection = "…")]Stream blob,
[Queue("imagestoolarge", Connection = "…")]ICollector<string> imagesTooLarge,
TraceWriter log)

25. 25

26. 26
Blob and queue
• Simply supply message
content
• Depends on input type
(string, byte[] or
POCO class)
HttpRequestMessage
• Able to be constructed
as dummy object
• Set properties for Body
and Headers
• Similar for
HttpResponse(Message)
TraceWriter
• Inherit and override
Write method for mock
• Alternatively use ILogger
provided through DI

27. 27
Demo
Debugging and unit testing
Azure Functions

28. 28
Moving into
production

29. 29
Consumption-based
Scaling as needed
Might require time to provide compute instances
App Service plan
Available scale
Not so much server-less
Easy to combine with PaaS
Azure Functions Runtime
Local installation of hosts
Connected via SQL Server database
Infrastructure operations
Not so much server-less
Azure On-premises

30. 30

31. 31

32. 32
{
"IsEncrypted": false,
"Values": {
"AzureWebJobsStorage": "",
"key1": "value1"
},
"ConnectionStrings": {
"db": {
"ConnectionString": “...",
"ProviderName": "System.Data.SqlClient"
}
}
} local.settings.json file

33. 33
Demo
Deploying Azure Functions

34. 34
{
"aggregator": {
"batchSize": 1000,
"flushTimeout": "00:00:30"
},
"logger": {
"categoryFilter": {
"defaultLevel": "Information",
"categoryLevels": {
"Host": "Error",
"Function": "Error",
"Host.Aggregator": "Information"
}
}
}
}

35. 35

36. 36
Single responsibility principle
Do one thing focussed
Finish as quickly as possible
Avoid long running functions
Stateless, idempotent and defensive
Cross function communication
Messaging: Storage Queues (small <64 KB) or Service Bus (<256 KB)
Service Bus topics for message filtering
Event Hub for high volume messaging

37. 37
Thank you!

38. 38
Resources
https://aka.ms/tryfunctions
https://functions.azure.com
https://docs.microsoft.com/en-us/azure/azure-functions/
https://github.com/Azure/Azure-Functions
Channel9

39. 39

40. 40

41. 41
docker build –t azurefunctionindocker .
docker run –p 8080:80 azurefunctionindocker
FROM microsoft/azure-functions-runtime:v2.0.0-beta1
ENV AzureWebJobsScriptRoot=/home/site/wwwroot
COPY . /home/site/wwwroot