403 forbidden for AWS Beanstalk Flask static files without SSL
I think I found the problem. I was inspecting by EB SSH just to understand what was going on and I noticed that the "ec2-user" I got logged in the AWS machine could access (running cd command) till the directory
/opt/python/current/appbut ec2-user wasn't allow to access dir
/opt/python/current/app/flaskAppbecause of permissions.
While the static dirs and files contained in flaskApp yet had permissions set on 755, I noticed that flaskApp dir (which contains static dir) was 744 (that I thought would be fine). So I changed flaskApp dir permissions to 755 and it worked: now static files get loaded!
By the way I doubt this permissions set is good for production. The alternative could be to structure dirs so that static isn't a subdirectory of flaskApp dir, allowing this way to keep static dir set on 755 while having flaskApp dir set on more conservative permissions.
The owner/group being root may be irrelevant if the files aren't viewable by all users. Make sure they're accessible to all by running a chmod 664 on all the static files.