mod_proxy_scgi - Apache HTTP Server Version 2.4









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Apache HTTP Server Version 2.4



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Apache Module mod_proxy_scgi

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Description:SCGI gateway module for mod_proxy
Status:Extension
Module Identifier:proxy_scgi_module
Source File:mod_proxy_scgi.c
Compatibility:Available in version 2.2.14 and later
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.
    

Topics

 Examples
 Environment Variables
Directives

 ProxySCGIInternalRedirect
 ProxySCGISendfile

Bugfix checklisthttpd changelogKnown issuesReport a bugSee also

mod_proxy
mod_proxy_balancer
Comments


Examples
    Remember, in order to make the following examples work, you have to
    enable mod_proxy and mod_proxy_scgi.

    Simple gatewayProxyPass "/scgi-bin/" "scgi://localhost:4000/"


    The balanced gateway needs mod_proxy_balancer and
    at least one load balancer algorithm module, such as
    mod_lbmethod_byrequests, in addition to the proxy
    modules listed above.  mod_lbmethod_byrequests is the
    default, and will be used for this example configuration.

    Balanced gatewayProxyPass "/scgi-bin/" "balancer://somecluster/"
<Proxy "balancer://somecluster">
    BalancerMember "scgi://localhost:4000"
    BalancerMember "scgi://localhost:4001"
</Proxy>



Environment Variables
    In addition to the configuration directives that control the
    behaviour of mod_proxy, an environment
    variable may also control the SCGI protocol
    provider:
    
        proxy-scgi-pathinfo
        By default mod_proxy_scgi will neither create
        nor export the PATH_INFO environment variable. This allows
        the backend SCGI server to correctly determine SCRIPT_NAME
        and Script-URI and be compliant with RFC 3875 section 3.3.
        If instead you need mod_proxy_scgi to generate
        a "best guess" for PATH_INFO, set this env-var.  The
        variable must be set before SetEnv
        is effective.  SetEnvIf can be
        used instead: SetEnvIf Request_URI . proxy-scgi-pathinfo
        
    


ProxySCGIInternalRedirect Directive

Description:Enable or disable internal redirect responses from the
backend
Syntax:ProxySCGIInternalRedirect On|Off|Headername
Default:ProxySCGIInternalRedirect On
Context:server config, virtual host, directory
Status:Extension
Module:mod_proxy_scgi
Compatibility:The Headername feature is available in version
2.4.13 and later

    The ProxySCGIInternalRedirect enables the backend
    to internally redirect the gateway to a different URL. This feature
    originates in mod_cgi, which internally redirects the
    response if the response status is OK (200) and
    the response contains a Location (or configured alternate
    header) and its value starts with a slash (/). This value is 
    interpreted as a new local URL that Apache httpd internally redirects to.

    mod_proxy_scgi does the same as
    mod_cgi in this regard, except that you can turn off the
    feature or specify the use of a header other than Location.

    Example    ProxySCGIInternalRedirect Off

# Django and some other frameworks will fully qualify "local URLs"
# set by the application, so an alternate header must be used.
<Location /django-app/>
    ProxySCGIInternalRedirect X-Location
</Location>




ProxySCGISendfile Directive

Description:Enable evaluation of X-Sendfile pseudo response
header
Syntax:ProxySCGISendfile On|Off|Headername
Default:ProxySCGISendfile Off
Context:server config, virtual host, directory
Status:Extension
Module:mod_proxy_scgi

    The ProxySCGISendfile directive enables the
    SCGI backend to let files be served directly by the gateway. This is useful
    for performance purposes — httpd can use sendfile or other
    optimizations, which are not possible if the file comes over the backend
    socket.  Additionally, the file contents are not transmitted twice.
    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 the filename to serve.
    The  header is removed from the final response headers. This is equivalent to
    ProxySCGISendfile X-Sendfile.

    anything else
    Similar to On, but instead of the hardcoded header name
    X-Sendfile, the argument is used as the header name.
    

    Example# Use the default header (X-Sendfile)
ProxySCGISendfile On

# Use a different header
ProxySCGISendfile X-Send-Static





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