Serverless Framework: Adding a Layer with IAM – A Step-by-Step Guide

Are you tired of managing complex infrastructure for your serverless applications? Do you want to simplify your development process and focus on writing code? Look no further! In this article, we’ll show you how to add a layer with IAM using the Serverless Framework. By the end of this tutorial, you’ll be able to deploy your serverless application with confidence.

What is Serverless Framework?

The Serverless Framework is an open-source framework that enables you to build and deploy serverless applications on cloud providers like AWS, Google Cloud, and Azure. It provides a simple and efficient way to manage your serverless infrastructure, allowing you to focus on writing code rather than managing servers.

What is a Layer in Serverless Framework?

In the Serverless Framework, a layer is a reusable package of code or dependencies that can be shared across multiple functions. Layers are particularly useful when you need to use a specific library or dependency in multiple functions. By creating a layer, you can avoid duplicating code and reduce the size of your function deployments.

Why Use Layers with IAM?

When you use a layer with IAM, you can manage access to your layer using IAM roles. This provides an additional layer of security and control over who can access your layer and its dependencies. By using IAM roles, you can ensure that only authorized users and services can access your layer, reducing the risk of unauthorized access.

Prerequisites

Before we dive into the tutorial, make sure you have the following prerequisites:

• A Serverless Framework project set up and configured
• An AWS account with IAM set up
• The AWS CLI installed and configured
• A basic understanding of IAM roles and permissions

Step 1: Create an IAM Role

In this step, we’ll create an IAM role that will be used to manage access to our layer. Follow these instructions:

1. Log in to the AWS Management Console and navigate to the IAM dashboard
2. Click on “Roles” in the left-hand menu and then click “Create role”
3. Choose “Custom role” and click “Next: Review”
4. In the “Role name” field, enter a name for your role (e.g. “LayerExecutionRole”)
5. In the “Description” field, enter a brief description of your role
6. Click “Create role”

Take note of the role ARN, which will be used later in this tutorial.

Step 2: Create a Layer

In this step, we’ll create a layer using the Serverless Framework. Follow these instructions:

1. Open your Serverless Framework project in your preferred code editor
2. Create a new file called `layer.js` with the following code:

   
     // layer.js
     exports.handler = async (event) => {
       console.log('Hello from the layer!');
       return { statusCode: 200 };
     };
     

3. Create a new file called `serverless.yml` with the following code:

   
     # serverless.yml
     service: my-layer
   
     provider:
       name: aws
       runtime: nodejs14.x
   
     layers:
       my-layer:
         path: layer.js
         compatibleRuntimes:
           - nodejs14.x
     

This code defines a simple layer that logs a message to the console when executed. We’ll add more functionality to this layer later.

Step 3: Add IAM Permissions to the Layer

In this step, we’ll add IAM permissions to our layer using the `iam` property in the `serverless.yml` file. Follow these instructions:

1. Open the `serverless.yml` file and add the following code:

   
     # serverless.yml
     ...
     layers:
       my-layer:
         path: layer.js
         compatibleRuntimes:
           - nodejs14.x
         iam:
           role:
             statements:
               - Effect: "Execute"
                 Resource: "arn:aws:lambda:*:*:layer:*"
             roleName: !Sub "LayerExecutionRole-${AWS::Region}"
     

2. Update the `roleName` property with the ARN of the IAM role you created in Step 1

This code adds an IAM role to the layer, allowing it to execute with the necessary permissions.

Step 4: Deploy the Layer

In this step, we’ll deploy the layer to AWS using the Serverless Framework. Follow these instructions:

1. Open a terminal and navigate to the root of your Serverless Framework project
2. Run the command `serverless deploy –layer my-layer` to deploy the layer

This command will deploy the layer to AWS and create a new layer version.

Step 5: Verify the Layer

In this step, we’ll verify that the layer has been deployed successfully and that it’s using the IAM role we created. Follow these instructions:

1. Open the AWS Lambda dashboard and navigate to the “Layers” tab
2. Find the layer you just deployed and click on it
3. Verify that the layer is using the IAM role you created in Step 1
4. Verify that the layer is deployed to the correct region and account

If everything is set up correctly, you should see the layer listed in the Lambda dashboard with the correct IAM role and deploy details.

Conclusion

In this tutorial, we’ve shown you how to add a layer with IAM using the Serverless Framework. By following these steps, you can simplify your serverless development process and ensure that your layers are secure and manageable. Remember to update your layer code and IAM permissions as needed to ensure that your layer is functioning as intended.

Keyword	Description
Serverless Framework	An open-source framework for building and deploying serverless applications
Layer	A reusable package of code or dependencies that can be shared across multiple functions
IAM	AWS Identity and Access Management, a service that provides fine-grained access control and identity management
IAM Role	A set of permissions that define what actions can be performed on AWS resources

By following this tutorial, you’ve taken the first step in mastering the Serverless Framework and building scalable, secure, and efficient serverless applications. Happy coding!

Frequently Asked Question

Serverless Framework adding layer with IAM can be a bit tricky, but don’t worry, we’ve got you covered! Here are some FAQs to help you navigate through the process.