Apache Module mod_proxy_scgi
Summary
This module requires the service of mod_proxy
. It provides support for the SCGI protocol, version 1.
Thus, in order to get the ability of handling the SCGI protocol, mod_proxy
and mod_proxy_scgi
have to be present in the server.
Warning
Do not enable proxying until you have secured your server. Open proxy servers are dangerous both to your network and to the Internet at large.
Examples
Remember, in order to make the following examples work, you have to enable mod_proxy
and mod_proxy_scgi
.
Simple gateway
ProxyPass /scgi-bin/ scgi://localhost:4000/
The balanced gateway needs mod_proxy_balancer
in addition to the already mentioned proxy modules.
Balanced gateway
ProxyPass /scgi-bin/ balancer://somecluster/
<Proxy balancer://somecluster/>
BalancerMember scgi://localhost:4000/
BalancerMember scgi://localhost:4001/
</Proxy>
ProxySCGIInternalRedirect Directive
The ProxySCGIInternalRedirect
enables the backend to internally redirect the gateway to a different URL. This feature origins in mod_cgi
, which internally redirects the response, if the response status is OK
(200
) and the response contains a Location
header and its value starts with a slash (/
). This value is interpreted as a new local URL the apache internally redirects to.
mod_proxy_scgi
does the same as mod_cgi
in this regard, except that you can turn off the feature.
Example
ProxySCGIInternalRedirect Off
ProxySCGISendfile Directive
The ProxySCGISendfile
directive enables the SCGI backend to let files serve directly by the gateway. This is useful performance purposes -- the httpd can use sendfile
or other optimizations, which are not possible if the file comes over the backend socket.
The ProxySCGISendfile
argument determines the gateway behaviour:
Off
- No special handling takes place.
On
- The gateway looks for a backend response header called
X-Sendfile
and interprets the value as filename to serve. The header is removed from the final response headers. This is equivalent to ProxySCGIRequest X-Sendfile
. - anything else
- Similar to
On
, but instead of the hardcoded header name the argument is applied as header name.
Example
# Use the default header (X-Sendfile)
ProxySCGISendfile On
# Use a different header
ProxySCGISendfile X-Send-Static