Global AI Web Application Delivery with CloudFront

Question

Pulumi · Accepted Answer

To deploy a global AI web application using Amazon CloudFront, you would typically need an S3 bucket to hold your web application's static files, such as HTML, CSS, JavaScript, and images. CloudFront will act as a content delivery network (CDN) to cache and serve these static assets from locations close to your users around the world, reducing latency and improving load times.

Here's how you would set this up with Pulumi using Python:

1. **Create an S3 Bucket**: This bucket will store the static assets for your web application.
2. **Configure CloudFront Distribution**: This tells CloudFront how to handle requests for your content, including which S3 bucket to use as the origin.
3. **Upload Static Content**: Optionally, you can use Pulumi to upload your initial set of static web content to the S3 bucket.
4. **Output the CloudFront Distribution URL**: Once the stack is deployed, you will receive the CloudFront Distribution URL which you can use to access your web application globally.

Below is the Python program that accomplishes these steps:

```python
import pulumi
import pulumi_aws as aws

# Create an AWS resource (S3 Bucket) to store the application's static content
bucket = aws.s3.Bucket("web-content-bucket", 
                        website=aws.s3.BucketWebsiteArgs(index_document="index.html"))

# Configure a CloudFront distribution to serve the bucket's content
cdn = aws.cloudfront.Distribution("cdn",
    # The distribution's configuration includes information about the origins
    # this distribution will service content from.
    origins=[aws.cloudfront.DistributionOriginArgs(
        domain_name=bucket.bucket_regional_domain_name,
        origin_id=bucket.arn,
        s3_origin_config=aws.cloudfront.DistributionOriginS3OriginConfigArgs(
            origin_access_identity=""  # Can be configured to restrict access to the S3 content
        ),
    )],
    enabled=True,
    is_ipv6_enabled=True,
    # The default cache behavior dictates the behavior of the distribution
    # when a request matches no other cache behavior.
    default_cache_behavior=aws.cloudfront.DistributionDefaultCacheBehaviorArgs(
        allowed_methods=["GET", "HEAD"],
        cached_methods=["GET", "HEAD"],
        target_origin_id=bucket.arn,
        forwarded_values=aws.cloudfront.DistributionDefaultCacheBehaviorForwardedValuesArgs(
            query_string=False,
            cookies=aws.cloudfront.DistributionDefaultCacheBehaviorForwardedValuesCookiesArgs(
                forward="none"
            )
        ),
        viewer_protocol_policy="allow-all",
        min_ttl=0,
        default_ttl=3600,
        max_ttl=86400,
    ),
    # Optional: Add custom error responses (404, etc.)
    custom_error_responses=[aws.cloudfront.DistributionCustomErrorResponseArgs(
        error_code=404,
        response_code=404,
        response_page_path="/404.html"
    )],
    # Strictest SSL/TLS policy
    viewer_certificate=aws.cloudfront.DistributionViewerCertificateArgs(
        cloudfront_default_certificate=True
    ),
    # This option is highly recommended as it tells CloudFront to compress your content
    # to save on bandwidth costs.
    default_root_object="index.html",
    # The aliases setting allows you to use your custom domain names
    # (e.g., www.example.com) instead of the cloudfront.net domain name
    aliases=["www.yourapplicationdomain.com"],
    price_class="PriceClass_All")

# (Optional) Upload initial content to the bucket
# index_content = pulumi.FileAsset("./app/index.html")
# index = aws.s3.BucketObject("index",
#     bucket=bucket.id,
#     key="index.html",
#     source=index_content
# )

# The CloudFront distribution URL to access your web application
pulumi.export('cloudfront_url', cdn.domain_name)
```

In this code, we set up the S3 bucket and CloudFront distribution configured to deliver your web application's static content. The CloudFront distribution's main behaviors include caching content, handling error responses, compressing content where possible, and setting up aliases for a custom domain name, if applicable.

Additionally, the optional snippet to upload an `index.html` file to the S3 bucket serves as an example of how you can manage your web content within the Pulumi program. Uncomment and adapt the optional snippet to upload your web application's initial content.

After deploying this code with Pulumi, any changes to this Pulumi program can be used to manage your web application's infrastructure. For example, you can update caching behavior, add additional custom error responses, or manage your web application's content.