9.4 - Project 3: Implementing a Serverless Function with AWS Lambda
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Interactive Audio Lesson
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Creating a DynamoDB Table
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To start our serverless function project, we need to create a DynamoDB table. What do you think is the purpose of DynamoDB in this context?
Isnβt it to store the data that we receive from our form submissions?
Exactly! In this project, we'll create a table named 'FormSubmissions'. We will use 'id' as the primary key. Why do you think we should use a unique identifier for each form submission?
It helps prevent data overwriting and allows us to fetch specific records easily!
Great point! Always remember, unique IDs ensure data integrity. Let's move on to creating the Lambda function.
Creating a Lambda Function
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Now, we need to create our Lambda function. Which programming languages can we use for this?
We can use Node.js or Python, right?
Correct! We also need to attach an IAM role that allows our Lambda function to write to DynamoDB. Can anyone remind us what IAM stands for?
Identity and Access Management!
Exactly! Managing permissions properly is crucial in cloud environments. Now letβs discuss the function code.
Writing Lambda Function Code
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Let's talk about writing our Lambda function code. What do we need to handle in the code when we receive data from our form?
We need to parse the incoming data from the form, right?
Yes! Weβll use `json.loads()` if we are coding in Python to convert the incoming JSON body into a Python dictionary. Remember that we need to store 'name' and 'email' in DynamoDB as well?
So, weβll use `put_item` to write that data into the table?
Exactly! Lastly, don't forget to return a status code. Can anyone tell me what status code we usually return for a successful request?
A 200 status code!
Perfect! Letβs proceed to the API Gateway.
Creating an API Gateway
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We now need to create an API Gateway that connects to our Lambda function. Why is it important to set up a POST method?
Because we want to send data to our function!
Exactly! Also, we'll need to enable CORS to allow the client-side form to interact with our API. Does anyone remember what CORS stands for?
Cross-Origin Resource Sharing!
Good job! Enabling CORS prevents security issues when accessing the API from different origins. Finally, let's deploy and test it.
Testing the Setup
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Now that we have deployed the API, how can we test if everything is functioning correctly?
We can use Postman or submit the form via a frontend website!
Right! When testing, make sure to monitor the data stored in DynamoDB. What should we confirm once we submit the form?
We need to check if the data has been saved correctly and that we receive the success response from the API.
Exactly! It's crucial to validate every step. In summary, today we covered creating a DynamoDB table, setting up a Lambda function, writing the function code, establishing an API Gateway, and testing our setup.
Introduction & Overview
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Quick Overview
Standard
In this section, readers learn to implement a serverless function using AWS Lambda to process contact form submissions and save data to a DynamoDB table. The process includes creating a DynamoDB table, writing Lambda function code, and using API Gateway to integrate the function.
Detailed
Project 3: Implementing a Serverless Function with AWS Lambda
In this project, we focus on utilizing AWS Lambda to create a serverless function that processes data from a contact form submission and stores that data in a DynamoDB table. This project consists of several key steps that readers will need to follow to successfully deploy a Lambda function with an API Gateway.
Key Steps Covered:
- Creating a DynamoDB Table: We first set up a DynamoDB table named
FormSubmissionswith a primary key ofidto store form submissions. - Creating a Lambda Function: Next, we create a Lambda function using either Node.js or Python and assign it an IAM role that grants permission to write data to our DynamoDB table.
- Writing Function Code: The core of the project involves writing the Lambda function code which processes the input from the form and saves it into DynamoDB using the Boto3 library in Python or the AWS SDK in Node.js.
- Creating an API Gateway: We then create an API Gateway to set up a POST endpoint that triggers our Lambda function when the form is submitted, ensuring that CORS is enabled to allow requests from different origins.
- Deployment and Testing: Finally, we deploy the API and test our setup with tools like Postman or through a frontend form, validating that form data is successfully recorded in DynamoDB.
This project synthesizes key AWS concepts such as serverless architecture, DynamoDB, and application programming interfaces (APIs), preparing users for real-world applications and enhancing their AWS expertise.
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Goal of the Project
Chapter 1 of 6
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Chapter Content
π Goal:
Create a simple AWS Lambda function that processes form input (e.g., a contact form) and stores it in DynamoDB.
Detailed Explanation
The primary goal of this project is to build a serverless function using AWS Lambda. This function will handle inputs from a form, like a contact form, and save the submitted data to a database known as DynamoDB. This means that users can submit their information, and it will be securely stored in the cloud without the need for traditional server infrastructure.
Examples & Analogies
Think of this function as an automated receptionist in an office. When someone fills out a contact form to inquire about services, the receptionist (Lambda function) takes the information and writes it down (stores it in DynamoDB) without any physical paperwork, ensuring that the inquiries are organized and easily accessible.
Creating a DynamoDB Table
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Chapter Content
β
Steps:
1. Create a DynamoDB Table:
- Table name: FormSubmissions
- Primary key: id
Detailed Explanation
The first step in setting up our serverless function is to create a table in DynamoDB called 'FormSubmissions.' This table will store data submitted through our form. Each entry in this table will have a unique identifier known as the primary key (in this case, 'id'), which helps to ensure that each submission can be retrieved or modified without confusion.
Examples & Analogies
Imagine the DynamoDB table as a filing cabinet where each form entry is a piece of paper. The 'id' acts like an address label on each piece of paper, ensuring you can find exactly the right paper later when you need it.
Creating a Lambda Function
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Chapter Content
- Create a Lambda Function:
- Choose Node.js or Python.
- Attach IAM role with DynamoDB write access.
Detailed Explanation
In the second step, you will create an AWS Lambda function. You need to choose a programming language for your function, such as Node.js or Python. Additionally, you must associate this Lambda function with an IAM role that has permissions to write data to the DynamoDB table you created. This role acts like a security badge, allowing the Lambda function access to the DynamoDB resources it needs to operate.
Examples & Analogies
Think of the Lambda function as a courier who collects form submissions. The IAM role is like a delivery permit that gives the courier (Lambda function) permission to enter different offices (DynamoDB) to deliver messages (data) securely.
Writing Function Code
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Chapter Content
- Write Function Code (example in Python):
import json
import boto3
import uuid
def lambda_handler(event, context):
db = boto3.resource('dynamodb')
table = db.Table('FormSubmissions')
data = json.loads(event['body'])
table.put_item(Item={
'id': str(uuid.uuid4()),
'name': data['name'],
'email': data['email']
})
return {
'statusCode': 200,
'body': json.dumps('Data saved successfully!')
}
Detailed Explanation
In this step, you write the actual code for your Lambda function. The provided Python code imports necessary libraries and defines a function called 'lambda_handler.' When this function is triggered, it retrieves data sent to it (like the form submission), generates a unique ID for the entry, and saves it in the 'FormSubmissions' table. The function also sends back a success message once the data has been saved.
Examples & Analogies
Consider this code as the set of instructions given to the courier. It tells them how to read the submissions, create a unique identification for each submission, and where to drop off the informationβin the filing cabinet (DynamoDB).
Creating API Gateway
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Chapter Content
- Create API Gateway:
- Setup POST endpoint to trigger Lambda.
- Enable CORS.
Detailed Explanation
The next step involves setting up an API Gateway, which serves as the entry point for HTTP requests to your Lambda function. You need to establish a POST endpoint that triggers the Lambda execution when data is sent to it, and also enable CORS (Cross-Origin Resource Sharing) to allow web applications running on different domains to interact with your API securely.
Examples & Analogies
Think of the API Gateway as a reception desk in a hotel. It allows guests (users) to submit their requests/forms at the desk (endpoint), which then calls the right department (Lambda function) to handle those requests efficiently.
Deploying and Testing the API
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Chapter Content
- Deploy API and test using Postman or a frontend form.
Detailed Explanation
Finally, once your API Gateway is configured, you will deploy it to make it live. After deployment, you can use tools like Postman or a frontend form to send test submissions to your API. This step ensures that your Lambda function is triggered correctly and that data is being stored in the DynamoDB table as expected.
Examples & Analogies
This step is like having a soft launch of a new service. You invite a few trusted people (testers) to use the service and provide feedback. It allows you to ensure everything runs smoothly before officially opening it up to everyone.
Key Concepts
-
AWS Lambda: A service that executes code in response to events, enabling the creation of serverless applications.
-
DynamoDB: A NoSQL database service that stores data as key-value pairs without the need for a fixed schema.
-
IAM Role: A defined set of permissions for AWS services associated with resources in your account.
-
API Gateway: A managed service making it easy to create and publish APIs, allowing Lambda functions to be triggered from HTTP requests.
-
CORS: A protocol to enable restricted access to resources from different domains.
Examples & Applications
An example of a contact form submission application that utilizes AWS Lambda and DynamoDB to process user inputs.
A real-world scenario where Lambda functions are employed for processing image uploads and storing references in a DynamoDB table.
Memory Aids
Interactive tools to help you remember key concepts
Rhymes
Lambdaβs the champ for serverless tech,
Stories
Imagine a busy post office where each form submitted is like a letter sent to a friend. AWS Lambda is the postal worker, processing each letter (form data) and storing it in a big filing cabinet (DynamoDB) for future retrieval, with the rules of sharing (CORS) making sure the post office operates smoothly.
Memory Tools
To remember the setup steps, think of 'LIDS': L for Lambda, I for IAM, D for DynamoDB, S for Setup API Gateway.
Acronyms
The 'C.A.R.D' helps remember important parts
for CORS
for API Gateway
for Role (IAM)
for DynamoDB.
Flash Cards
Glossary
- AWS Lambda
A serverless compute service that lets you run code in response to events without provisioning servers.
- DynamoDB
A fully managed NoSQL database service that provides fast and predictable performance with seamless scalability.
- IAM Role
A set of permissions that define what actions are allowed and denied on AWS resources.
- API Gateway
A service that allows developers to create, publish, maintain, monitor, and secure APIs at any scale.
- CORS
Cross-Origin Resource Sharing, a security feature that allows restricted resources on a web page to be requested from another domain.
Reference links
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