C# on AWS Lambda

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About me

Pat Hermens

● Father of two

● Based in Rotterdam

● Lead Developer at Coolblue

● Still have a soft-spot for VB6

https://hermens.com.au/ 2

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Every day a little more Dutch

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A little bit of history

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Launched in Nov 2014.5

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C# support in Dec 2016.6

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Officially only supports .NET Core.7

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AWS was first of the “major providers”.8

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They have an open-source SDKhttps://github.com/aws/aws-sdk-net/ 9

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They also have a great ‘dotnet’ repo…https://github.com/aws/aws-lambda-dotnet/ 10

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… & most of my tooling is from here11

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It’s “Hello world” time!

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Hello World! (including ILambdaContext)

“Relatively simple” configuration14

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Wait, we need more than code!

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Set up an account

Install the CLI

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Regions? AZ’s?

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IAM?

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Required values can be set in code!

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… or on the command line!

NOW it’s “Hello world” time!

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Hello World! (including ILambdaContext)

Deploying “Hello-World”

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Running deploy-function & invoke-function

Calling our “Hello” function

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We can use the ‘Amazon’ NuGet package(s)

We can use AWS SNS29

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We can use any ‘webhook’-type integration30

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Creating a “Hello-World-Caller”

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Pretty straightforward using the SDK

Just F5 in VS Code!33

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Larger architectures?

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Our “infra team” had a fun exercise...35

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CloudFormation - scripted infrastructure36

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Normally looks like this...37

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… but can also look like this!38

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“Add trigger” to your Lambda39

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Pick your integration - whatever you want!40

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Or just, “deploy-serverless” with the CLI41

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AWS Serverless Application Modelhttp://github.com/awslabs/ 42

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http://serverless.com/framework/docs/ 43

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So, what does this mean for Coolblue?44

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This makes it look simple!45

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Let’s recap some “gotchas”

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Timings can vary wildly!

Default values can bite you!48

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Know your costs! 800,000 sec = 9.25 dayshttps://aws.amazon.com/lambda/pricing/ 49

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Almost everything is case-sensitive!50

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PS> dotnet lambda deploy-function HelloWorld-EUWest# New Lambda function created

PS> dotnet lambda invoke-function helloworld-euwest -p "Pat"# Error invoking Lambda function: Function not found: arn:aws:lambda:eu-west-1:955206359773:function:helloworld-euwest

‘ILambdaContext’ should ALWAYS be last51

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public string SayHi(ILambdaContext context, string name = "World"){

// … do something}

RESPONSE: (only on invocation, after deployment){ "errorType": "LambdaException", "errorMessage":

"Method 'SayHi' of type 'MyFirstLambdaFunction.HelloWorld' is not supported:the method has 2 parameters, but the second parameter is not of type'Amazon.Lambda.Core.ILambdaContext'."

}

Read the FAQ’s! https://aws.amazon.com/lambda/faqs/ 52

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Q: How are compute resources assigned to an AWS Lambda function?In the AWS Lambda resource model, you choose the amount of memory you want for your function, and are allocated proportional CPU power and other resources.

For example, choosing 256MB of memory allocates approximately twice as much CPU power to your Lambda function as requesting 128MB of memory and half as much CPU power as choosing 512MB of memory. You can set your memory in 64MB increments from 128MB to 1.5GB.

Containers can be reused!https://aws.amazon.com/blogs/compute/container-reuse-in-lambda/ 53

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Handy links

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Tooling● https://github.com/aws/aws-sdk-net/● https://github.com/aws/aws-lambda-dotnet/

Documentation● http://github.com/awslabs/● http://serverless.com/framework/docs/● https://aws.amazon.com/lambda/faqs/

https://aws.amazon.com/documentation/ 55

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Thanks!

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Tonight’s demos are on GitHub (but they’re really nothing special!)

● https://github.com/pheonix25/lambda-helloworld

● https://github.com/pheonix25/lambda-helloworldcaller

Thanks!

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