RequestHeader with Apache environment variable
Solution 1:
Late but still, I've just dealt with the same issue, and this worked for me:
RequestHeader set X_FORWARDED_PROTO 'https' env=HTTPS
The documentation says:
When the RequestHeader directive is used with the add, append, or set argument, a fourth argument may be used to specify conditions under which the action will be taken. If the environment variable specified in the env=... argument exists (or if the environment variable does not exist and env=!... is specified) then the action specified by the RequestHeader directive will take effect. Otherwise, the directive will have no effect on the request.
While the HTTPS environment variable is only set when the request is made through SSL.
Solution 2:
You don't want that; it'd set your header to "HTTP/1.1" (even on an https request) - probably not terribly useful to whatever you're passing to.
You have different VirtualHost blocks for http and https; just hardcode the RequestHeader
setting in each.
<VirtualHost *:80>
RequestHeader set X-Forwarded-Proto "http"
...
</VirtualHost>
<VirtualHost *:443>
RequestHeader set X-Forwarded-Proto "https"
...
</VirtualHost>
Solution 3:
You can fix this by using the early
keyword:
RequestHeader set X-Forwarded-Proto "https" early
Otherwise, you can do what John Crenshaw suggested, which is use RewriteRule
instead of ProxyPass
directives.
Solution 4:
Found the cause. Turns out it is an order of operations issue. mod_rewrite is responsible for supplying these environment variables, but Apache doesn't process it until AFTER it handles any ProxyPass requests. Until then, it will just set null. The only workaround appears to be to do the proxying via mod_rewrite.
See http://www.gossamer-threads.com/lists/apache/users/267160?do=post_view_threaded#267160