AWS Certificate Manager (ACM) Integration | Overview.

twtech Overview of AWS Certificate Manager (ACM) Integration.

Intro:

This covers how ACM integrates with AWS services, what is automated, what is manual, and how it ties into a multi-account and multi-region environment.

Break down:

•        Overview,
•        Integration Architecture,
•        Integration Flow Sample (Public ACM Certificates),
•        Integration with ACM Private CA,
•        Multi-Region & Multi-Account Integration,
•        Automation & CI/CD Integration,
•        Monitoring & Operations,
•        Reference Architecture Diagram.

 Overview

AWS Certificate Manager (ACM) is a fully managed service that handles provisioning, deployment, and renewal of SSL/TLS certificates for use with AWS services and twtech internal applications.

There are two main types of ACM certificates:

• Public Certificates – Issued by Amazon’s public CA and automatically trusted by browsers.
• Private Certificates – Issued by twtech own ACM Private CA.

Integration Architecture

ACM integrates natively with several AWS services to secure traffic (HTTPS/TLS) and automate certificate management.

Key Integrated Services

Category	AWS Service	Integration Function
Compute / Web	Elastic Load Balancing (ALB, NLB, CLB)	ACM certificates can be directly attached to Load Balancer listeners.
	Amazon CloudFront	ACM (in us-east-1) issues public certs for CDN distributions.
	AWS API Gateway	ACM certs secure custom domain endpoints.
	AWS App Runner / ECS / EKS	ACM certs used via Load Balancer or Ingress controllers.
Networking / Edge	AWS Global Accelerator	Supports ACM certificates for static IP endpoints.
	AWS Cloud Map	Uses ACM for service discovery endpoints (HTTPS).
Private Infrastructure	ACM Private CA + PrivateLink / VPC Endpoints	Issue internal-use-only certificates.
Automation & Deployment	CloudFormation / CDK / Terraform	Automates certificate requests, validation (DNS), and attachments.
Security & Compliance	AWS Organizations, IAM, CloudTrail, Config	Track and control certificate use and compliance posture.

 Integration Flow Sample (Public ACM Certificates)

Let’s walk through a typical automated integration pattern:

1. Certificate Request
• CloudFormation or Lambda requests a public ACM certificate for a domain (e.g., api.example.com).
2. DNS Validation
• ACM provides a CNAME record for validation.
• A Route 53 automation stack creates the validation record automatically (using delegation or cross-account automation).
3. Validation & Issuance
• ACM validates the DNS record and issues the certificate.
• CloudFormation waits for the “Issued” state.
4. Attachment
• The certificate ARN is passed to a Load Balancer or CloudFront distribution for deployment.
5. Auto Renewal
• ACM handles renewal.
• DNS validation records remain valid for future renewals.
6. Cross-Account Use (Optional)
• Certificate ARNs shared via Resource Access Manager (RAM).
• Other accounts can reference the certificate for use in ALBs, etc.

 Integration with ACM Private CA

Feature	Description
Private CA Creation	Managed CA created in ACM PCA.
Private Certificate Issuance	ACM requests a cert from your Private CA.
Integration Points	Works with internal ELBs, App Mesh, IoT, or private APIs.
Security Controls	IAM policies and permissions control who can issue and use private certs.
Audit / Logging	All CA and certificate operations logged via CloudTrail and optional CRL or OCSP publishing.

 Multi-Region & Multi-Account Integration

To scale ACM across an enterprise setup:

• Centralized Certificate Management Account
• Requests and owns ACM certs (public or private).
• Shares certs via AWS RAM.
• Application Accounts
• Consume shared certificates (e.g., ALB, API Gateway).
• Automation
• CloudFormation StackSets or Lambda handle DNS validation automatically in each region/account.

NB:

Best Practice: Centralize ACM + Route 53 under a “Shared Services” account.

 Automation & CI/CD Integration

Tool	Use Case
CloudFormation	Define and provision ACM certs and attach to ELB, API Gateway, etc.
AWS CLI / SDK	Scripted requests, validation checks, rotation automation.
Lambda Automation	Rotate imported certs, automate DNS validation updates.
CodePipeline	Integrate ACM validation and certificate deployment into CI/CD.

 Monitoring & Operations

• CloudWatch Metrics
• CertificateRenewalElapsedTime, Issued, PendingValidation
• AWS Config Rules
• Detect expired or expiring certificates.
• AWS Health Dashboard
• ACM-managed certificate events (e.g., renewal failure).
• CloudTrail
• Audit certificate requests, imports, and attachments.

 Reference Architecture Diagram

ACM Integration – Public Certificates Automation