AWS Cloudfront + Load Balancer, url changes from main domain to load balancer subdomain

Solution 1:

This behavior likely results from the fact that by default CloudFront sets the Host: HTTP request header to the origin hostname, in this case elb.example.com. The application then presumably generates links based on that hostname.

If, instead, you configure CloudFront to whitelist that header for forwarding to the origin, the Host header sent by the browser (example.com) will be sent on to the application by CloudFront, so the application should behave more like you'd expect and use that value when generating the links. With this, CloudFront still uses the origin server hostname to do the DNS lookup needed in order to establish the TCP connection to the origin (the ELB in this case), but stops injecting that hostname into the HTTP request headers.

http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/distribution-web-values-specify.html#DownloadDistValuesForwardHeaders

This has been answered by @michael-sqlbot on SO