Rewrite#
The module is used to change request URI using PCRE regular expressions, return redirects, and conditionally select configurations.
The break, goto, if, return, rewrite, and set directives are processed in the following order:
the directives of this module specified on the server level are executed sequentially;
repeatedly:
When building from the source code, the module is built by
default; it can be disabled with the build option
--without-http_rewrite_module.
In packages and images from our repositories, the
module is included in the build. Stops processing the current set of http_rewrite module directives. If a directive is specified inside the location, further processing of the request continues in this location. Example: Added in version 1.12.0. Stops processing the current set of Redirecting to a named location counts toward the same limit of 10 URI changes
used when a request URI is rewritten. For example, requests without a The specified condition is evaluated. If true, this module directives specified inside the braces are executed, and the request is assigned the configuration inside the if directive. Configurations inside the if directives are inherited from the previous configuration level. Warning Although directives from other modules can be used inside the if block,
this is not recommended,
as it may lead to unexpected behavior. A condition may be any of the following: a variable name; false if the value of a variable is an empty string or "0"; comparison of a variable with a string using the "=" and "!=" operators; matching of a variable against a regular expression using the "~" (for case-sensitive matching) and "~*" (for case-insensitive matching) operators. Regular expressions can contain captures that are made available for later reuse in the $1..$9 variables. Negative operators "!~" and "!~*" are also available. If a regular expression includes the "}" or ";" characters, the whole expressions should be enclosed in single or double quotes. checking of a file existence with the "-f" and "!-f" operators; checking of a directory existence with the "-d" and "!-d" operators; checking of a file, directory, or symbolic link existence with the "-e" and "!-e" operators; checking for an executable file with the "-x" and "!-x" operators. Examples: Note The value of the $invalid_referer built-in variable is set by the valid_referers directive. Stops processing and returns the specified It is possible to specify either a redirect URL (for codes 301, 302, 303, 307, and 308) or the response body text (for other codes). A response body text and redirect URL can contain variables. As a special case, a redirect URL can be specified as a URI local to this server, in which case the full redirect URL is formed according to the request scheme ($scheme) and the server_name_in_redirect and port_in_redirect directives. In addition, a URL for temporary redirect with the code 302 can be specified as the sole parameter. Such a parameter should start with the See also the error_page directive. If the specified regular expression matches a request URI, URI is changed as specified in the The replacement string can contain variables, including the positional captures An optional stops processing the current set of http_rewrite module directives and starts a search for a new location matching the changed URI; stops processing the current set of http_rewrite module directives as with the break directive; returns a temporary redirect with the 302 code; used if a returns a permanent redirect with the 301 code. The full redirect URL is formed according to the request scheme ($scheme) and the server_name_in_redirect and port_in_redirect directives. Example: But if these directives are put inside the "/download/" location, the If a If a regular expression includes the "}" or ";" characters, the whole expressions should be enclosed in single or double quotes. Enables or disables logging of http_rewrite module directives processing results into the error_log at the notice level. Sets a value for the specified variable. The value can contain variables. Default http, server, location, if Controls whether warnings about uninitialized variables are logged. The http_rewrite module directives are compiled at the configuration stage into internal instructions that are interpreted during request processing. An interpreter is a simple virtual stack machine. For example, the directives will be translated into these instructions: Note that there are no instructions for the limit_rate directive, since it is not related to the The directive can be made one instruction shorter if the first slash is moved inside the parentheses in the regular expression: The corresponding instructions will then look like this:Directives#
break#
if ($slow) {
limit_rate 10k;
break;
}
goto#
http_rewrite module directives and
performs an unconditional internal redirect to the named location given by the name parameter. Unlike rewrite, it
does not change $uri. The parameter must be a name prefixed with
@; otherwise, the configuration is rejected.session cookie can be routed to a
dedicated authentication backend:if ($cookie_session = "") {
goto @auth_backend;
}
location / {
proxy_pass http://backend;
}
location @auth_backend {
proxy_pass http://127.0.0.1:8000;
proxy_set_header Host $host;
}
if#
if ($http_user_agent ~ MSIE) {
rewrite ^(.*)$ /msie/$1 break;
}
if ($http_cookie ~* "id=([^;]+)(?:;|$)") {
set $id $1;
}
if ($request_method = POST) {
return 405;
}
if ($slow) {
limit_rate 10k;
}
if ($invalid_referer) {
return 403;
}
return#
code to a client. The non-standard code 444 closes a connection without sending a response header.http://, https://, or "$scheme" string. A URL can contain variables.rewrite#
replacement string. The rewrite directives are executed sequentially in order of their appearance in the configuration file. It is possible to terminate further processing of the directives using flags. If a replacement string starts with http://, https://, or "$scheme", the processing stops and the redirect is returned to a client.$1 to $9.flag parameter can be one of:lastbreakredirectreplacement string does not start with http://, https://, or "$scheme";permanentserver {
# ...
rewrite ^(/download/.*)/media/(.*)\..*$ $1/mp3/$2.mp3 last;
rewrite ^(/download/.*)/audio/(.*)\..*$ $1/mp3/$2.ra last;
return 403;
# ...
}
last flag should be replaced by break, or otherwise Angie will make 10 cycles and return the 500 error:location /download/ {
rewrite ^(/download/.*)/media/(.*)\..*$ $1/mp3/$2.mp3 break;
rewrite ^(/download/.*)/audio/(.*)\..*$ $1/mp3/$2.ra break;
return 403;
}
replacement string includes the new request arguments, the previous request arguments are appended after them. If this is undesired, putting a question mark at the end of a replacement string avoids having them appended, for example:rewrite ^/users/(.*)$ /show?user=$1? last;
rewrite_log#
set#
uninitialized_variable_warn#
uninitialized_variable_warn on | off;uninitialized_variable_warn on;Internal Implementation#
location /download/ {
if ($forbidden) {
return 403;
}
if ($slow) {
limit_rate 10k;
}
rewrite ^/(download/.*)/media/(.*)\..*$ /$1/mp3/$2.mp3 break;
}
variable $forbidden
check for zero
return 403
end of code
variable $slow
check for zero
match of regular expression
copy "/"
copy $1
copy "/mp3/"
copy $2
copy ".mp3"
end of regular expression
end of code
http_rewrite module. A separate configuration is created for the if block. If the condition is true, the request gets this configuration, where limit_rate equals 10k.rewrite ^/(download/.*)/media/(.*)\..*$ /$1/mp3/$2.mp3 break;
rewrite ^(/download/.*)/media/(.*)\..*$ $1/mp3/$2.mp3 break;
match of regular expression
copy $1
copy "/mp3/"
copy $2
copy ".mp3"
end of regular expression
end of code
Content