# Task 2: Set up cross-origin resource sharing (CORS)
<a name="module-2"></a>


|  |  | 
| --- |--- |
| **Time to complete** | 5 minutes  | 
| **Requires** |  +  An AWS account: If you don't already have an account, follow the [Setting Up Your Environment](https://docs.aws.amazon.com/hands-on/latest/setup-environment/) tutorial.  <br />+  An internet browser    | 
| **Get help** | [Amazon S3 Troubleshooting](https://docs.aws.amazon.com/AmazonS3/latest/userguide/object-ownership-error-responses.html)  | 

## Overview
<a name="overview"></a>

In this task, you will create an Amazon S3 bucket and set up cross-origin resource sharing (CORS). This S3 bucket will be used to store data by the user.

## Implementation
<a name="implementation"></a>

### Step 1: Create an S3 bucket
<a name="create-an-s3-bucket"></a>

1. Create an S3 bucket

   Open [Amazon S3 console](https://console.aws.amazon.com/s3/) and choose **Create bucket**.  
![The Amazon S3 page in the AWS Management Console.](https://docs.aws.amazon.com/hands-on/latest/set-up-an-aws-transfer-family-web-app/images/s3-banner.png)

1. Configure bucket details

   For **Bucket name**, enter a descriptive, globally unique name, for example, **transfer-family-web-app-demo-<your-username>**.

   Leave the remaining options as defaults. Scroll to the bottom of the page and choose **Create bucket**.  
![The Amazon S3 page for creating a bucket.](https://docs.aws.amazon.com/hands-on/latest/set-up-an-aws-transfer-family-web-app/images/s3-bucket-details.png)

### Step 2: Set up CORS
<a name="set-up-cors"></a>

1. Open bucket permissions

   After the bucket is created, on the **General purpose buckets** tab, search for the bucket you created, select its **Name**, and then choose the **Permissions** tab.   
![The configuration settings interface.](https://docs.aws.amazon.com/hands-on/latest/set-up-an-aws-transfer-family-web-app/images/transfer-family-set-cors-abebdcd.png)

1. Configure CORS settings

   1. In **Cross-origin resource sharing (CORS)**, choose **Edit** and paste in the following code. 

     ```
     [
       {
         "AllowedHeaders": [
           "*"
         ],
         "AllowedMethods": [
           "GET",
           "PUT",
           "POST",
           "DELETE",
           "HEAD"
         ],
         "AllowedOrigins": [
           "AccessEndpoint"
         ],
         "ExposeHeaders": [
           "last-modified",
           "content-length",
           "etag",
           "x-amz-version-id",
           "content-type",
           "x-amz-request-id",
           "x-amz-id-2",
           "date",
           "x-amz-cf-id",
           "x-amz-storage-class",
           "access-control-expose-headers"
         ],
         "MaxAgeSeconds": 3000
       }
     ]
     ```

     Replace **AccessEndpoint** with the actual **InstanceARN** you copied in the previous task. 
**Note**  
Do not enter trailing slashes because trailing slashes will cause errors when users attempt to log into the web app.
     + Correct example: **https://webapp-b4d851af6e314fc39.transfer-webapp.us-west-2.on.aws** 
     + Incorrect example: **https://webapp-b4d851af6e314fc39.transfer-webapp.us-west-2.on.aws******/**** 

     Choose **Save changes**.  
![Interface element requiring manual review.](https://docs.aws.amazon.com/hands-on/latest/set-up-an-aws-transfer-family-web-app/images/transfer-family-set-cors-edca-eba.png)

## Conclusion
<a name="conclusion"></a>

In this task, you’ve learned how to create an S3 bucket and set up cross-origin resource sharing (CORS).