.NET 6 Web API in a Container in a Lambda
Want to learn more about AWS Lambda and .NET? Check out my A Cloud Guru course on ASP.NET Web API and Lambda.
I have a few other posts on running .NET 6 on AWS Lambda.
Introduction
At the time of posting, AWS Lambda does not support .NET 6 with a managed runtime. But it is still very easy to deploy a .NET 6 Lambda Web API as a container image. In this post, you will see how with just a few commands you can build and deploy a Web API application in a container, in a Lambda, and make it accessible over the web!
You don’t even need Visual Studio, VS Code, or Rider!!
If your goal is to use managed runtime when it is available, the only change you will need to make is to use a different .NET template (Docker won’t be necessary either).
tl;dr just show me the commands!
Prerequisites
- You need an AWS account, you can get one for free.
- Install and configure the AWS CLI.
- The .NET 6 SDK.
- Docker.
Installing the tools
Install the Amazon Lambda tools -
dotnet tool install -g Amazon.Lambda.Tools
And the Amazon Lambda Templates -
dotnet new -i Amazon.Lambda.Templates
After they are installed you can see all the available .NET 6 Lambda templates using -
dotnet new ".NET 6" --list --tag Lambda
Template Name Short Name Language Tags
---------------------------------------------------- -------------------------------------------- -------- ---------------------
Lambda ASP.NET Core Web API (.NET 6 Container Image) serverless.image.AspNetCoreWebAPI [C#],F# AWS/Lambda/Serverless
Lambda Custom Runtime Function (.NET 6) lambda.CustomRuntimeFunction [C#],F# AWS/Lambda/Function
Lambda Empty Function (.NET 6 Container Image) lambda.image.EmptyFunction [C#],F# AWS/Lambda/Function
Lambda Empty Serverless (.NET 6 Container Image) serverless.image.EmptyServerless [C#],F# AWS/Lambda/ServerlessYou will be using “Lambda ASP.NET Core Web API (.NET 6 Container Image) serverless.image.AspNetCoreWebAPI”, the first on the list. But there are a couple of steps before you create the application.
Create the S3 bucket
The deployment tool needs an S3 bucket to store its template. Create that using -
aws s3api create-bucket --bucket cloudformation-templates-2022
Note, you must use a unique name for the bucket, you can’t use the one I used.
Start Docker
If you have Docker installed, start it. If not, install and start it.
Create the Web API application
Now that you have the Lambda templates you can create the Lambda container based .NET 6 Web API application with a simple command -
dotnet new serverless.image.AspNetCoreWebAPI --name AspNet6ContainerWebApi
Build and deploy
Change to the source code directory -
cd AspNet6ContainerWebApi\src\AspNet6ContainerWebApi
To see the deployment options run -
dotnet lambda
Commands to deploy and manage AWS Lambda functions:
deploy-function Command to deploy the project to AWS Lambda
invoke-function Command to invoke a function in Lambda with an optional input
list-functions Command to list all your Lambda functions
delete-function Command to delete a Lambda function
get-function-config Command to get the current runtime configuration for a Lambda function
update-function-config Command to update the runtime configuration for a Lambda function
Commands to deploy and manage AWS Serverless applications using AWS CloudFormation:
deploy-serverless Command to deploy an AWS Serverless application
list-serverless Command to list all your AWS Serverless applications
delete-serverless Command to delete an AWS Serverless application
snip...“deploy-serverless” is what you need. It takes a couple of parameters, the name of the CloudFormation stack, and the name of the S3 bucket created earlier -
dotnet lambda deploy-serverless --stack-name AspNet6ContainerWebApi --s3-bucket cloudformation-templates-2022
If everything is working you will see something like -
Created CloudFormation stack AspNet6ContainerWebApi
Timestamp Logical Resource Id Status
-------------------- ---------------------------------------- ----------------------------------------
1/6/2022 11:07 AM AspNet6ContainerWebApi CREATE_IN_PROGRESS
1/6/2022 11:07 AM AspNetCoreFunctionRole CREATE_IN_PROGRESS
1/6/2022 11:07 AM AspNetCoreFunctionRole CREATE_IN_PROGRESS
1/6/2022 11:07 AM AspNetCoreFunctionRole CREATE_COMPLETE
1/6/2022 11:07 AM AspNetCoreFunction CREATE_IN_PROGRESS
1/6/2022 11:07 AM AspNetCoreFunction CREATE_IN_PROGRESS
snip...
Stack finished updating with status: CREATE_COMPLETE
Output Name Value
------------------------------ --------------------------------------------------
ApiURL https://xxxxxxxxxx.execute-api.us-east-1.amazonaws.com/Prod/The last line of the output is the URL of the API, it is publicly available.
Up and running
Use your favorite browser to test out the API.
Grab the ApiURL from above (replacing “xxxxxxxxxx” with the real URL) and open -
https://xxxxxxxxxx.execute-api.us-east-1.amazonaws.com/Prod/you will see “Welcome to running ASP.NET Core on AWS Lambda”https://xxxxxxxxxx.execute-api.us-east-1.amazonaws.com/Prod/api/values- you will see “[“value1”,“value2”]”
Cleaning up
To delete all the resources you created, run -
dotnet lambda delete-serverless --stack-name AspNet6ContainerWebApi.
Just the commands
If all you want are the commands to do everything quickly, here you are -
dotnet tool install -g Amazon.Lambda.Tools
dotnet new -i Amazon.Lambda.Templates
aws s3api create-bucket --bucket cloudformation-templates-2022
dotnet new serverless.image.AspNetCoreWebAPI --name AspNet6ContainerWebApi
cd AspNet6ContainerWebApi\src\AspNet6ContainerWebApi
dotnet lambda deploy-serverless --stack-name AspNet6ContainerWebApi --s3-bucket cloudformation-templates-2022
# clean up
# dotnet lambda delete-serverless --stack-name AspNet6ContainerWebApi