SSL redirect on EC2 instance behind SSL terminating load balancer
Solution 1:
untested.. but I try this
RewriteCond %{HTTP:X-Forwarded-Proto} !https
RewriteRule ^ https://%{SERVER_NAME}%{REQUEST_URI} [L,R]
http://docs.aws.amazon.com/ElasticLoadBalancing/latest/DeveloperGuide/TerminologyandKeyConcepts.html#x-forwarded-proto