How to connect a third-party subdomain (mes.lhe.co.kr) to AWS Amplify with SSL?

Connecting a third-party subdomain to your AWS Amplify-hosted application with SSL is certainly possible. Here's a step-by-step guide to help you achieve this:

1. DNS Configuration: You'll need to add a CNAME record in the DNS settings for your root domain (lhe.co.kr). The CNAME record should point your subdomain (mes.lhe.co.kr) to the Amplify domain provided for your app (typically something like xxxxxxxx.amplifyapp.com).

2. Verification: Yes, there is a verification step. After you add the custom domain in the Amplify console, Amplify will provide you with specific DNS records to add to your domain. This usually includes a CNAME record for domain verification.

3. TTL and Propagation: DNS changes can take some time to propagate globally. This can range from a few minutes to 48 hours, depending on your DNS provider and the TTL (Time to Live) settings. It's recommended to set a low TTL (e.g., 300 seconds) initially to allow for quicker propagation and easier troubleshooting.

4. SSL Certificates:

   • Yes, AWS Amplify automatically manages SSL certificates for custom domains, including third-party subdomains like mes.lhe.co.kr.
   • Domain validation is required, and it's typically done via DNS. Amplify will provide you with a CNAME record that you need to add to your DNS settings for validation.
   • To ensure SSL is successfully provisioned: a. Add the custom domain in the Amplify console. b. Follow the instructions provided by Amplify to add the necessary DNS records (both for domain verification and for routing traffic). c. Wait for the DNS changes to propagate and for Amplify to verify the domain ownership. d. Amplify will then automatically provision and manage the SSL certificate for your custom subdomain.

Once these steps are completed and the DNS changes have propagated, your subdomain (mes.lhe.co.kr) should be securely accessible via HTTPS and serve your Amplify-hosted application.

Remember to monitor the Amplify console during this process, as it will provide status updates and any additional instructions if needed. If you encounter any issues, double-check your DNS settings and ensure that all required records are correctly added.
Sources
Bring your own SSL certificate to AWS Amplify Hosting | Front-End Web & Mobile
AWS Amplify FAQs | Front-End Web & Mobile | Amazon Web Services
Community | AWS open source newsletter, #190