Apache HTTP Server Version 2.4
Description: | FastCGI support module for
mod_proxy |
---|---|
Status: | Extension |
Module Identifier: | proxy_fcgi_module |
Source File: | mod_proxy_fcgi.c |
Compatibility: | Available in version 2.3 and later |
This module requires the service of mod_proxy
. It provides support for the
FastCGI protocol.
Thus, in order to get the ability of handling the FastCGI
protocol, mod_proxy
and
mod_proxy_fcgi
have to be present in the server.
Unlike mod_fcgid
and mod_fastcgi,
mod_proxy_fcgi
has no provision for starting the
application process; fcgistarter
is provided
(on some platforms) for that purpose. Alternatively, external launching
or process management may be available in the FastCGI application
framework in use.
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.
Remember, in order to make the following examples work, you have to
enable mod_proxy
and mod_proxy_fcgi
.
ProxyPass "/myapp/" "fcgi://localhost:4000/"
mod_proxy_fcgi
disables connection reuse by
default, so after a request has been completed the connection will NOT be
held open by that httpd child process and won't be reused. If the
FastCGI application is able to handle concurrent connections
from httpd, you can opt-in to connection reuse as shown in the following
example:
ProxyPass "/myapp/" "fcgi://localhost:4000/" enablereuse=on
The following example passes the request URI as a filesystem path for the PHP-FPM daemon to run. The request URL is implicitly added to the 2nd parameter. The hostname and port following fcgi:// are where PHP-FPM is listening. Connection pooling/reuse is enabled.
ProxyPassMatch "^/myapp/.*\.php(/.*)?$" "fcgi://localhost:9000/var/www/" enablereuse=on
The following example passes the request URI as a filesystem path for the PHP-FPM daemon to run. In this case, PHP-FPM is listening on a unix domain socket (UDS). Requires 2.4.9 or later. With this syntax, the hostname and optional port following fcgi:// are ignored.
ProxyPassMatch "^/(.*\.php(/.*)?)$" "unix:/var/run/php5-fpm.sock|fcgi://localhost/var/www/"
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.
ProxyPass "/myapp/" "balancer://myappcluster/" <Proxy "balancer://myappcluster/"> BalancerMember "fcgi://localhost:4000" BalancerMember "fcgi://localhost:4001" </Proxy>
You can also force a request to be handled as a reverse-proxy request, by creating a suitable Handler pass-through. The example configuration below will pass all requests for PHP scripts to the specified FastCGI server using reverse proxy. This feature is available in Apache HTTP Server 2.4.10 and later. For performance reasons, you will want to define a worker representing the same fcgi:// backend. The benefit of this form is that it allows the normal mapping of URI to filename to occur in the server, and the local filesystem result is passed to the backend. When FastCGI is configured this way, the server can calculate the most accurate PATH_INFO.
<FilesMatch "\.php$"> # Note: The only part that varies is /path/to/app.sock SetHandler "proxy:unix:/path/to/app.sock|fcgi://localhost/" </FilesMatch> # Define a matching worker. # The part that is matched to the SetHandler is the part that # follows the pipe. If you need to distinguish, "localhost; can # be anything unique. <Proxy "fcgi://localhost/" enablereuse=on max=10> </Proxy> <FilesMatch ...> SetHandler "proxy:fcgi://localhost:9000" </FilesMatch> <FilesMatch ...> SetHandler "proxy:balancer://myappcluster/" </FilesMatch>
In addition to the configuration directives that control the
behaviour of mod_proxy
, there are a number of
environment variables that control the FCGI protocol
provider:
ProxyPass
or ProxyPassMatch
, mod_proxy_fcgi
will not
set the PATH_INFO environment variable. This allows
the backend FCGI server to correctly determine SCRIPT_NAME
and Script-URI and be compliant with RFC 3875 section 3.3.
If instead you need mod_proxy_fcgi
to generate
a "best guess" for PATH_INFO, set this env-var.
This is a workaround for a bug in some FCGI implementations. This
variable can be set to multiple values to tweak at how the best guess
is chosen (In 2.4.11 and later only):
Description: | Specify the type of backend FastCGI application |
---|---|
Syntax: | ProxyFCGIBackendType FPM|GENERIC |
Default: | ProxyFCGIBackendType FPM |
Context: | server config, virtual host, directory, .htaccess |
Status: | Extension |
Module: | mod_proxy_fcgi |
Compatibility: | Available in version 2.4.26 and later |
This directive allows the type of backend FastCGI application to be specified. Some FastCGI servers, such as PHP-FPM, use historical quirks of environment variables to identify the type of proxy server being used. Set this directive to "GENERIC" if your non PHP-FPM application has trouble interpreting environment variables such as SCRIPT_FILENAME or PATH_TRANSLATED as set by the server.
One example of values that change based on the setting of this directive is
SCRIPT_FILENAME. When using mod_proxy_fcgi
historically,
SCRIPT_FILENAME was prefixed with the string "proxy:fcgi://". This variable is
what some generic FastCGI applications would read as their script input, but
PHP-FPM would strip the prefix then remember it was talking to Apache. In
2.4.21 through 2.4.25, this prefix was automatically stripped by the server,
breaking the ability of PHP-FPM to detect and interoperate with Apache in some
scenarios.
Description: | Allow variables sent to FastCGI servers to be fixed up |
---|---|
Syntax: | ProxyFCGISetEnvIf conditional-expression
[!]environment-variable-name
[value-expression] |
Context: | server config, virtual host, directory, .htaccess |
Status: | Extension |
Module: | mod_proxy_fcgi |
Compatibility: | Available in version 2.4.26 and later |
Just before passing a request to the configured FastCGI server, the core of the web server sets a number of environment variables based on details of the current request. FastCGI programs often uses these environment variables as inputs that determine what underlying scripts they will process, or what output they directly produce.
Examples of noteworthy environment variables are:
This directive allows the environment variables above, or any others of interest, to be overridden. This directive is evaluated after the initial values for these variables are set, so they can be used as input into both the condition expressions and value expressions.
Parameter syntax:
# A basic, unconditional override ProxyFCGISetEnvIf "true" PATH_INFO "/example" # Use an environment variable in the value ProxyFCGISetEnvIf "true" PATH_INFO "%{reqenv:SCRIPT_NAME}" # Use captures in the conditions and backreferences in the replacement ProxyFCGISetEnvIf "reqenv('PATH_TRANSLATED') =~ m|(/.*prefix)(\d+)(.*)|" PATH_TRANSLATED "$1$3"
VARIABLE
, preventing it from being sent
to the FastCGI server:
ProxyFCGISetEnvIf true !VARIABLEWhereas the following will erase any existing value of
VARIABLE
(by setting it to the empty string), but the empty
VARIABLE
will still be sent to the server:
ProxyFCGISetEnvIf true VARIABLEThe CGI/1.1 specification does not distinguish between a variable with an empty value and a variable that does not exist. However, many CGI and FastCGI implementations distinguish (or allow scripts to distinguish) between the two. The choice of which to use is dependent upon your implementation and your reason for modifying the variable.