Building a Mirco-service with Lambda, API Gateway & S3

In this lab, we will creating a micro-service based webpage which shall button tied to API gateway which in turns tied to Lambda function which shall return some value as response whenever the button is clicked from frontend

Here’s an architectural diagram for it

1. Let’s start creating this with Lambda function
   
2. Input the Name of lambda function
   Choose Python 3.7 as a runtime
   Role: Create a new role from one or more template
   And give the role a name
   
3. Now copy below code inside lambda editor & save it

   def lambda_handler(event, context):
       print("In lambda handler")
       
       resp = {
           "statusCode": 200,
           "headers": {
               "Access-Control-Allow-Origin": "*",
           },
           "body": "Dabeer Shaikh"
       }
       
       return resp

4. Now from service menu go to API Gateway service
   
5. Choose below option and create an API Gateway
   
6. After creation of API Gateway you will get a window like below
   
7. Now from Actions lets create a method
   
8. This shall be a GET method since we wanna get some response from our lambda function
   
9. On left side after creating GET method, please do below setting and input your lambda function name
   This ties your API Gateway with Lambda
   
10. Now deloy your API
    

11. You shall get an API URL try to open it, this shall invoke our lambda function and try to get response from the Lambda function
    
12. Response from Lambda
    
13. Now we need to intregate this API URL with webpage, for this download this WEBPAGE
    Once the index.html file is downloaded open it in Notepad and replace the API URL with your API URL
    
14. Now once you have edited the API URL in index.html page, upload that file to a S3 bucket
    
15. Make the index.html file public and open it in web browser
    
16. It will open up a page similar to below
    Now if you click on “Click ME” you are hitting API URL which in turns shall invoke a lambda function and get a reponse from it
    
17. This is response is from lambda
    
18. You can delete all resources created during this lab