Update an AWS Lambda .NET Core Function Using PowerShell

To deploy a .NET Core function to AWS Lambda, you can use the Visual Studio AWS Toolkit. I find the AWS Toolkit to be...annoying (or worse). It requires permissions unrelated to updating a function, it slows down Visual Studio, and it sometimes just crashes. Below is a simple PowerShell script that will build and update an AWS Lambda Function. The code makes the following assumptions.

• You have AWS Tools for PowerShell installed.
• The AWS Lambda Function is already created. You are only updating it.
• You have an AWS IAM User with the lambda:UpdateFunctionCode permission granted on the function in question.
• The AWS IAM User has its credentials stored in a local profile.

copy

$ErrorActionPreference = "Stop"


$lambda_function_name = "my-function-name"

$project_folder = "C:\Projects\MyFunctionProjectFolder\"

$zip_file = "$project_folder\output.zip"

# this assumes you have a profile in the C:\Users\myusername\.aws\credentials file
$aws_profile = "aws_profile_name"

$aws_region = "us-east-1"


#navigate to the project folder
cd $project_folder


#build react - optional, maybe you are deploying a .NET Core Razor Pages site with React, you will build react first
# npm install
# npm run build


#build
dotnet lambda package -o output.zip


#deploy
Update-LMFunctionCode -FunctionName $lambda_function_name -ZipFilename $zip_file -Region $aws_region -ProfileName $aws_profile


#delete the zipped build file
Remove-Item -Path $zip_file -Force

Example AWS Permissions Needed

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{
    "Version": "2012-10-17",
    "Statement": [
        {            
            "Effect": "Allow",
            "Action": "lambda:UpdateFunctionCode",
            "Resource": "arn:aws:lambda:us-east-1:123123123123:function:my-function-name"
        }
    ]
}