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Apache Module mod_proxy_fcgi 645d66

Available Languages:  fr 

Description: FastCGI 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

Summary 6m2os

This module requires the service of mod_proxy. It provides for the FastCGI protocol.

Thus, in order to get the ability of handling the FastCGI protocol, mod_proxy_fcgi have to be present in the server.

Unlike mod_fcgid and mod_fastcgi, 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.

Warning 6h505h

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.

 Apache!

Topics 2c136y

Directives 1a4l6m

Bugfix checklist 4i2533

See also 27136x

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Examples 412u42

, in order to make the following examples work, you have to enable mod_proxy_fcgi.

Single application instance 5ne3o

Proxy "/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:

Single application instance, connection reuse (2.4.11 and later) 41521k

Proxy "/myapp/" "fcgi://localhost:4000/" enablereuse=on

Enable connection reuse to a FCGI backend like PHP-FPM 3s5u5g

Please keep in mind that PHP-FPM (at the time of writing, February 2018) uses a prefork model, namely each of its worker processes can handle one connection at the time.
By default mod_proxy (configured with enablereuse=on) allows a connection pool of event), so the following use cases should be taken into :

The maximum number of PHP-FPM worker processes needs to be configured wisely, since there is the chance that they will all end up "busy" handling idle persistent connections, without any room for new ones to be established, and the end experience will be a pile of HTTP request timeouts.

The following example es 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.

PHP-FPM 1a465s

ProxyMatch "^/myapp/.*\.php(/.*)?$" "fcgi://localhost:9000/var/www/" enablereuse=on

The following example es 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.

PHP-FPM with UDS 1k1t3t

ProxyMatch "^/(.*\.php(/.*)?)$" "unix:/var/run/php5-fpm.sock|fcgi://localhost/var/www/"

The balanced gateway needs mod_lbmethod_byrequests is the default, and will be used for this example configuration.

Balanced gateway to multiple application instances 1m2w3n

Proxy "/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 -through. The example configuration below will 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 ed to the backend. When FastCGI is configured this way, the server can calculate the most accurate PATH_INFO.

Proxy via Handler 1w5f69

<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>
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Environment Variables 565751

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:

proxy-fcgi-pathinfo
When configured via 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):
first-dot
PATH_INFO is split from the slash following the first "." in the URL.
last-dot
PATH_INFO is split from the slash following the last "." in the URL.
full
PATH_INFO is calculated by an attempt to map the URL to the local filesystem.
unescape
PATH_INFO is the path component of the URL, unescaped / decoded.
any other value
PATH_INFO is the same as the path component of the URL. Originally, this was the only proxy-fcgi-pathinfo option.
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ProxyFCGIBackendType Directive 3bb60

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 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.

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ProxyFCGISetEnvIf Directive 6k92n

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 ing 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:

conditional-expression
Specifies an expression that controls whether the environment variable that follows will be modified. For information on the expression syntax, see the examples that follow or the full specification at the ap_expr documentation.
environment-variable-name
Specifies the CGI environment variable to change, such as PATH_INFO. If preceded by an exclamation point, the variable will be unset.
value-expression
Specifies the replacement value for the preceding environment variable. Backreferences, such as "$1", can be included from regular expression captures in conditional-expression. If omitted, the variable is set (or overridden) to an empty string — but see the Note below.
# 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"

Note: Unset vs. Empty 4c4j4v

The following will unset VARIABLE, preventing it from being sent to the FastCGI server:
ProxyFCGISetEnvIf true !VARIABLE
Whereas 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 VARIABLE
The 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.

Available Languages:  fr 

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Comments 2p1l6j

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