My first .NET core lambda function

Requirements

Build

To build the project, you will need dotnetcore installed

Deploy

To deploy create zip package you will need AWS cli installed

Test

For viewing lambda function log, you'll need jq and base64 libraries installed (or you can view logs in CloudWatch logs)

Quick Test

To quickly test application build, deployment and run, use test.sh script from top-level directory, it's assuming that you have bash shell installed

$ ./test.sh

Generate app

 dotnet new classlib -n lambda-hello-world

Define AWS NuGet dependencies

Add some dependency info in lambda-hello-world/lambda-hello-world.csproj

<ItemGroup>
  <PackageReference Include="Amazon.Lambda.Core" Version="1.0.0" />
  <PackageReference Include="Amazon.Lambda.Serialization.Json" Version="1.0.0" />
</ItemGroup>

Write some code

Code in this example will print out Lambda Function metadata, and exit with "OK" result

          Console.WriteLine("Hello world from Lambda function!");

          Console.WriteLine($"Function name: {context.FunctionName}");
          Console.WriteLine($"Function version: {context.FunctionVersion}");
          Console.WriteLine($"Function ARN: {context.InvokedFunctionArn}");

          Console.WriteLine($"Remaining lambda exection time: {context.RemainingTime.TotalMilliseconds}ms");

          return "OK";

Install dependencies and build application code

$ dotnet restore && dotnet build
  Restoring packages for .../github/dotnetcore-lambda/lambda-hello-world/lambda-hello-world.csproj...
  Lock file has not changed. Skipping lock file write. Path: .../github/dotnetcore-lambda/lambda-hello-world/obj/project.assets.json
  Restore completed in 389.34 ms for .../github/dotnetcore-lambda/lambda-hello-world/lambda-hello-world.csproj.

  NuGet Config files used:
      .../.nuget/NuGet/NuGet.Config

  Feeds used:
      https://api.nuget.org/v3/index.json
Microsoft (R) Build Engine version 15.1.1012.6693
Copyright (C) Microsoft Corporation. All rights reserved.

  lambda-hello-world -> .../github/dotnetcore-lambda/lambda-hello-world/bin/Debug/netcoreapp1.0/lambda-hello-world.dll

Build succeeded.
    0 Warning(s)
    0 Error(s)

Time Elapsed 00:00:02.45

Create lambda package

$ cd bin/Debug/netcoreapp1.0/publish/ && zip -r package.zip *

Create lambda function

$ aws lambda create-function --function-name TestDotNetCore --runtime "dotnetcore1.0" --role $LAMDBA_ROLE_ARN --region ap-southeast-2 --handler  lambda-hello-world::example.lambda_hello_world.LambdaHandler::HelloWorld --zip-file fileb://./lambda-hello-world/bin/Debug/netcoreapp1.0/publish/package.zip
{
    "TracingConfig": {
        "Mode": "PassThrough"
    },
    "CodeSha256": "gcP319XLaFzv9ZOken0dS/b81EbrrschaHvMG8LDT9w=",
    "FunctionName": "TestDotNetCore",
    "CodeSize": 214306,
    "MemorySize": 128,
    "FunctionArn": "arn:aws:lambda:ap-southeast-2:334818472548:function:TestDotNetCore",
    "Version": "$LATEST",
    "Role": "arn:aws:iam::XXXXXX:role/lambda_basic_execution",
    "Timeout": 3,
    "LastModified": "2017-06-15T03:14:31.929+0000",
    "Handler": "lambda-hello-world::example.lambda_hello_world.LambdaHandler::HelloWorld",
    "Runtime": "dotnetcore1.0",
    "Description": ""
}