By now there were four hostnames to serve: the company site, a brand guide, a profile and this blog. Four distributions would work, but one distribution with a router is less to look after.
Certificates cannot be edited
To add a name, you request a new certificate that lists every name and swap it onto the distribution. The script looks for an existing certificate with all the names first, so re-running it reuses what is there.
The router
A CloudFront Function runs on each request, looks at the Host header and prefixes the path. The three original hostnames are left alone and keep serving the bucket root.
var sites = {
'brand.kulkarniinc.com': '/sites/brand',
'profile.kulkarniinc.com': '/sites/profile',
'blog.kulkarniinc.com': '/sites/blog'
};Paths that end in a slash, or have no file extension, get /index.html appended.
Two gotchas
- The company site's deploy uses
aws s3 sync --delete, which would happily remove the other sites' folders. It now has--exclude "sites/*". - Files that are not content-hashed need a CloudFront invalidation after each deploy, or visitors keep the old copy. The deploy scripts create one.
One more limit to know: the distribution's error pages fall back to the company site's home page, so a mistyped URL on a subdomain shows that page rather than a custom 404.