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Pulumi

Pulumi is an open-source infrastructure as code SDK that allows you to define and deploy your cloud resources using a programming language of your choice. It's possible to define any kind of cloud resource, but given this is serverlessdotnet.dev let's build an AWS Lambda function.

The first thing you'll need to do is install Pulumi..

Once installed, create a new directory and initialize a project:

start-pulumi

mkdir PulumiServerless
cd PulumiServerless
mkdir PulumiDotnet.Serverless
cd PulumiDotnet.Serverless
pulumi new aws-csharp

Take note of the stack name used in the pulumi new wizard, you'll need this for deployment.

Let's also create a new Lambda function to use as an example.


cd ..
mkdir Functions
cd Functions
dotnet new lambda.EmptyFunction -n Dotnet.CDK.Lambda

Open up the generated project file called PulumiDotnet.Serverless.csproj.

Replace the Program.cs file with the below code:

Program.cs

using Pulumi;
using PulumiDotnet.Serverless;
return await Deployment.RunAsync<LambdaFunctionStack>();

Then add an additional class to the project named LambdaFunctionStack.

Update the contents with the below code:

Click Here for Code Sample
LambdaFunctionStack.cs

using Pulumi;
using Pulumi.Aws.Iam;
using Pulumi.Aws.Lambda;
namespace PulumiDotnet.Serverless;
public class LambdaFunctionStack : Stack
{
[Output] public Output<string> LambdaFunctionName { get; set; }
public LambdaFunctionStack()
{
var lambdaRole = new Role("lambdaRole", new RoleArgs
{
AssumeRolePolicy =
@"{
""Version"": ""2012-10-17"",
""Statement"": [
{
""Action"": ""sts:AssumeRole"",
""Principal"": {
""Service"": ""lambda.amazonaws.com""
},
""Effect"": ""Allow"",
""Sid"": """"
}
]
}"
});
var logPolicy = new RolePolicy("lambdaLogPolicy", new RolePolicyArgs
{
Role = lambdaRole.Id,
Policy =
@"{
""Version"": ""2012-10-17"",
""Statement"": [{
""Effect"": ""Allow"",
""Action"": [
""logs:CreateLogGroup"",
""logs:CreateLogStream"",
""logs:PutLogEvents""
],
""Resource"": ""arn:aws:logs:*:*:*""
}]
}"
});
// Create an AWS resource (S3 Bucket)
var lambda = new Function(
"PulumiDotnetLambda",
new FunctionArgs
{
Runtime = "dotnet6",
Code = new FileArchive("Functions/Dotnet.CDK.Lambda/src/Dotnet.CDK.Lambda/bin/Release/net6.0/linux-x64/publish"),
Handler = "Dotnet.CDK.Lambda::Dotnet.CDK.Lambda.Function::FunctionHandler",
Role = lambdaRole.Arn
});
LambdaFunctionName = lambda.Name;
}
}

IAM Role​

The first thing defined is an IAM role for the Lambda function to use. The role simply allows the Lambda service to assume it.

LambdaFunctionStack.cs

// ...
var lambdaRole = new Role("lambdaRole", new RoleArgs
{
AssumeRolePolicy =
@"{
""Version"": ""2012-10-17"",
""Statement"": [
{
""Action"": ""sts:AssumeRole"",
""Principal"": {
""Service"": ""lambda.amazonaws.com""
},
""Effect"": ""Allow"",
""Sid"": """"
}
]
}"
});
// ...

IAM Policy​

Next, an IAM policy is defined and attached to the role using the RolePolicy class.

LambdaFunctionStack.cs

// ...
var logPolicy = new RolePolicy(
"lambdaLogPolicy",
new RolePolicyArgs
{
Role = lambdaRole.Id,
Policy =
@"{
""Version"": ""2012-10-17"",
""Statement"": [{
""Effect"": ""Allow"",
""Action"": [
""logs:CreateLogGroup"",
""logs:CreateLogStream"",
""logs:PutLogEvents""
],
""Resource"": ""arn:aws:logs:*:*:*""
}]
}"
});
// ...

Lambda Function​

Finally, the Lambda function is defined and the name of it set to the Output name. Pulumi provides the FileArchive class to specify the files to be included in the ZIP and upload it to Amazon S3.

LambdaFunctionStack.cs

// ...
// Create an AWS resource (S3 Bucket)
var lambda = new Function(
"PulumiDotnetLambda",
new FunctionArgs
{
Runtime = "dotnet6",
Code = new FileArchive(
"Functions/Dotnet.CDK.Lambda/src/Dotnet.CDK.Lambda/bin/Release/net6.0/linux-x64/publish"),
Handler = "Dotnet.CDK.Lambda::Dotnet.CDK.Lambda.Function::FunctionHandler",
Role = lambdaRole.Arn
});
this.LambdaFunctionName = lambda.Name;
// ...

IAM Role​

The first thing defined is an IAM role for the Lambda function to use. The role simply allows the Lambda service to assume it.

IAM Policy​

Next, an IAM policy is defined and attached to the role using the RolePolicy class.

Lambda Function​

Finally, the Lambda function is defined and the name of it set to the Output name. Pulumi provides the FileArchive class to specify the files to be included in the ZIP and upload it to Amazon S3.

LambdaFunctionStack.cs
ExpandClose

// ...
var lambdaRole = new Role("lambdaRole", new RoleArgs
{
AssumeRolePolicy =
@"{
""Version"": ""2012-10-17"",
""Statement"": [
{
""Action"": ""sts:AssumeRole"",
""Principal"": {
""Service"": ""lambda.amazonaws.com""
},
""Effect"": ""Allow"",
""Sid"": """"
}
]
}"
});
// ...

Once defined, run the below commands from a terminal window in the PulumiServerless folder.

deploy

dotnet publish ./Functions/Dotnet.CDK.Lambda/src/Dotnet.CDK.Lambda/ -c Release -r linux-x64
cd PulumiDotnet.Serverless
pulumi stack select STACK_NAME_SPECIFIED_EARLIER
pulumi up

Once deployed, invoke the Lambda function in AWS using the below command replacing the OUTPUT_FUNCTION_NAME with the value output to your terminal:


dotnet lambda invoke-function -n OUTPUT_FUNCTION_NAME -p hello