Skip to main content

AWS DVA-C02 Drill: API Gateway Custom Domain - ACM Region & DNS Setup

Jeff Taakey
Author
Jeff Taakey
21+ Year Enterprise Architect | AWS SAA/SAP & Multi-Cloud Expert.

Jeff’s Note
#

Unlike generic exam dumps, ArchitectDecisionHub analyzes this scenario through the lens of a Real-World Lead Developer.

For AWS DVA-C02 candidates, the confusion often lies in which AWS region to import SSL certificates into and how DNS records relate to CloudFront distributions vs API Gateway endpoints. In production, this is about knowing exactly where ACM certificates must reside to integrate properly when using CloudFront in front of API Gateway. Let’s drill down.

The Certification Drill (Simulated Question)
#

Scenario
#

A tech startup named ZenSoft Solutions is building a new customer engagement platform. The platform includes an Amazon API Gateway REST API deployed in the us-west-2 Region. ZenSoft wants to enhance the API’s performance and security by fronting it with Amazon CloudFront and using a custom domain name, smokeyapi.zensoft.com. The team has obtained an SSL/TLS certificate for smokeyapi.zensoft.com from DigiCert, a third-party CA.

The Requirement:
#

How should the ZenSoft developer configure the custom domain name with SSL/TLS certificate to correctly integrate CloudFront and API Gateway, ensuring the application is accessible securely through the custom domain?

The Options
#

  • A) Import the SSL/TLS certificate into AWS Certificate Manager (ACM) in the same Region as the API Gateway (us-west-2). Create a DNS A record pointing the custom domain to the API Gateway endpoint.
  • B) Import the SSL/TLS certificate directly into the CloudFront distribution. Create a DNS CNAME record pointing the custom domain to the CloudFront distribution.
  • C) Import the SSL/TLS certificate into AWS Certificate Manager (ACM) in the same Region as the API Gateway (us-west-2). Create a DNS CNAME record pointing the custom domain to the CloudFront distribution.
  • D) Import the SSL/TLS certificate into AWS Certificate Manager (ACM) in the us-east-1 Region. Create a DNS CNAME record pointing the custom domain to the CloudFront distribution.

Google adsense
#

leave a comment:

Correct Answer
#

D

Quick Insight: The Developer Imperative
#

When using CloudFront with a custom domain, ACM certificates must be in the us-east-1 Region because CloudFront only integrates with certificates from ACM in us-east-1. Attempting to import certificates in other regions or use API Gateway regional certificates directly will cause SSL validation to fail or require incorrect DNS settings.

Content Locked: The Expert Analysis
#

You’ve identified the answer. But do you know the implementation details that separate a Junior from a Senior?


The Expert’s Analysis
#

Correct Answer
#

Option D

The Winning Logic
#

CloudFront distributions require ACM certificates to be imported specifically in the us-east-1 (N. Virginia) Region. This is because CloudFront is a global service that only recognizes ACM certificates issued in or imported into us-east-1. Since the API Gateway is deployed in us-west-2 and the frontend is CloudFront, the SSL/TLS certificate must be imported into us-east-1 ACM to associate with CloudFront’s custom domain name configuration.

Additionally, DNS must use a CNAME record pointing to the CloudFront distribution’s domain name because CloudFront acts as the front door. The SSL handshake and validation occur at CloudFront, not directly at the API Gateway endpoint.

The Trap (Distractor Analysis):
#

  • Why not A?
    ACM certificates in the API Gateway’s region (us-west-2) can be used only if the custom domain is associated directly with API Gateway Regional or Edge-Optimized endpoint. But when using CloudFront in front, CloudFront must hold the certificate in us-east-1. Also, pointing DNS A record to API Gateway bypasses CloudFront, breaking the intended architecture.

  • Why not B?
    You cannot import a third-party SSL/TLS certificate directly into CloudFront. CloudFront requires certificates to be managed via ACM in us-east-1 or use Amazon-issued certificates. Direct import into CloudFront invalidates the setup.

  • Why not C?
    Same reason as A: certificates must be in us-east-1 for CloudFront. Having ACM cert in us-west-2 cannot be attached to CloudFront distributions.


The Technical Blueprint
#

Developer CLI Snippet: Importing Certificate to ACM in us-east-1 and associating with CloudFront
#

# Import third-party certificate into ACM in us-east-1
aws acm import-certificate \
  --region us-east-1 \
  --certificate fileb://certificate.pem \
  --private-key fileb://private_key.pem \
  --certificate-chain fileb://chain.pem \
  --tags Key=Project,Value=ZenSoftAPI

# Then update CloudFront distribution configuration to attach ACM certificate ARN from us-east-1
aws cloudfront update-distribution \
  --id E2EXAMPLE1234 \
  --distribution-config file://cf-config-with-acm.json

The Comparative Analysis
#

Option ACM Region DNS Record Type Usable with CloudFront? Correct Setup for Custom Domain + CloudFront
A us-west-2 (API RG) A No DNS points to API Gateway, bypasses CloudFront
B N/A (direct import) CNAME No CloudFront does not accept direct cert imports
C us-west-2 (API RG) CNAME No ACM cert in wrong region for CloudFront
D us-east-1 CNAME Yes Correct ACM region and proper DNS pointing to CloudFront

Real-World Application (Practitioner Insight)
#

Exam Rule
#

“For the exam, always remember: CloudFront requires ACM certificates in us-east-1, regardless of API Gateway region.”

Real World
#

“In production, many overlook ACM regional constraints and try to upload certs in API regions, wasting time debugging SSL handshake failures. Designing multi-region APIs with CloudFront requires centralized certificate management workflows.”


(CTA) Stop Guessing, Start Mastering
#


Disclaimer

This is a study note based on simulated scenarios for the AWS DVA-C02 exam.

The DevPro Network: Mission and Founder

A 21-Year Tech Leadership Journey

Jeff Taakey has driven complex systems for over two decades, serving in pivotal roles as an Architect, Technical Director, and startup Co-founder/CTO.

He holds both an MBA degree and a Computer Science Master's degree from an English-speaking university in Hong Kong. His expertise is further backed by multiple international certifications including TOGAF, PMP, ITIL, and AWS SAA.

His experience spans diverse sectors and includes leading large, multidisciplinary teams (up to 86 people). He has also served as a Development Team Lead while cooperating with global teams spanning North America, Europe, and Asia-Pacific. He has spearheaded the design of an industry cloud platform. This work was often conducted within global Fortune 500 environments like IBM, Citi and Panasonic.

Following a recent Master’s degree from an English-speaking university in Hong Kong, he launched this platform to share advanced, practical technical knowledge with the global developer community.


About This Site: AWS.CertDevPro.com


AWS.CertDevPro.com focuses exclusively on mastering the Amazon Web Services ecosystem. We transform raw practice questions into strategic Decision Matrices. Led by Jeff Taakey (MBA & 21-year veteran of IBM/Citi), we provide the exclusive SAA and SAP Master Packs designed to move your cloud expertise from certification-ready to project-ready.