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How to get started with .Net Core and Lambda functions?

 Recently I started experimenting with .Net Core and AWS Lambda functions, I thought I will share the steps I took to get started

Tools to install

  1. .Net Core 3.1 - https://dotnet.microsoft.com/download/dotnet-core/3.1
  2. AWS CLI - https://aws.amazon.com/cli/ 
  3. AWS Account - 12 months Free Tier - https://aws.amazon.com/free
  4. Terminal - on iOS I use iTerm2 - https://www.iterm2.com 
Once you installed the above tools, head to AWS console and login with your root account to create an account which will be used by AWS CLI. Please see steps here 

Now you can configure AWS CLI as detailed here. Verify that you able to connect to AWS service using CLI.

To make life little easy with dotnet core and Lambda functions, you need to install AWS Extensions nuget pack for .Net CLI

dotnet tool install -g Amazon.Lambda.Tools
You can also install templates to get started quickly 

dotnet new -i Amazon.Lambda.Templates

That's it. Now the fun part!!! 

Create a new project

  1. In terminal window, check the templates installed.
dotnet new help
Pick a template for Lambda functions. For this example I have used serverless.AspNetCoreWebAPI

dotnet new serverless.AspNetCoreWebAPI -n SampleApp
This will create a new app under SampleApp folder. Navigate to SampleApp/src/SampleApp folder and build the app

dotnet build
Now run the app locally

dotnet run
This will start you .Net API running locally. The magic is happening in LocalEntryPoint.cs file which is like your Program.cs which contains the main method and which bootstraps your api. Now you can test your api on localhost:5000 or 5001

If you get error while testing on https port, use this command 

dotnet dev-certs https --trust
You can view detailed article about this issue from Scott Hanselman.

In the next post we will look at how to deploy Lambda function in your AWS account. 


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