uri

Manipulates a request's URI. It can strip path prefix/suffix or replace substrings on the whole URI.

This directive is distinct from rewrite in that uri differentiably changes the URI, rather than resetting it to something completely different as rewrite does. While rewrite is treated specially as an internal redirect, uri is just another middleware.

Syntax

Multiple different operations are supported:

uri [<matcher>] strip_prefix <target>
uri [<matcher>] strip_suffix <target>
uri [<matcher>] replace      <target> <replacement> [<limit>]
uri [<matcher>] path_regexp  <target> <replacement>
uri [<matcher>] query        [-|+]<param> [<value>]
uri [<matcher>] query {
	<param> [<value>] [<replacement>]
	...
}

The first (non-matcher) argument specifies the operation:

strip_prefix strips the prefix from the path.
strip_suffix strips the suffix from the path.
replace performs a substring replacement across the whole URI.
- <target> is the prefix, suffix, or search string/regular expression. If a prefix, the leading forward slash may be omitted, since paths always start with a forward slash.
- <replacement> is the replacement string. Supports using capture groups with $name or ${name} syntax, or with a number for the index, such as $1. See the Go documentation for details. If the replacement value is "", then the matching text is removed from the value.
- <limit> is an optional limit to the maximum number of replacements.
path_regexp performs a regular expression replacement on the path portion of the URI.
- <target> is the prefix, suffix, or search string/regular expression. If a prefix, the leading forward slash may be omitted, since paths always start with a forward slash.
- <replacement> is the replacement string. Supports using capture groups with $name or ${name} syntax, or with a number for the index, such as $1. See the Go documentation for details. If the replacement value is "", then the matching text is removed from the value.
query performs manipulations on the URI query, with the mode depending on the prefix to the parameter name or the count of arguments. A block can be used to specify multiple operations at once, grouped and performed in this order: rename 🡒 set 🡒 append 🡒 replace 🡒 delete.
- With no prefix, the parameter is set with the given value in the query.
  
  For example, uri query foo bar will set the value of the foo param to bar.
- Prefix with - to remove the parameter from the query.
  
  For example, uri query -foo will delete the foo parameter from the query.
- Prefix with + to append a parameter to the query, with the given value. This will not overwrite an existing parameter with the same name (omit the + to overwrite).
  
  For example, uri query +foo bar will append foo=bar to the query.
- A param with > as an infix will rename the parameter to the value after the >.
  
  For example, uri query foo>bar will rename the foo parameter to bar.
- With three arguments, query value regular expression replacement is performed, where the first arg is the query param name, the second is the search value, and the third is the replacement. The first arg (param name) may be * to perform the replacement on all query params.
  
  Supports using capture groups with $name or ${name} syntax, or with a number for the index, such as $1. See the Go documentation for details. If the replacement value is "", then the matching text is removed from the value.
  
  For example, uri query foo ^(ba)r $1z would replace the value of the foo param, where the value began with bar resulting in the value becoming baz.

URI mutations occur on the normalized or unescaped form of the URI. However, escape sequences can be used in the prefix or suffix patterns to match only those literal escapes at those positions in the request path. For example, uri strip_prefix /a/b will rewrite both /a/b/c and /a%2Fb/c to /c; and uri strip_prefix /a%2Fb will rewrite /a%2Fb/c to /c, but won't match /a/b/c.

The URI path is cleaned of directory traversal dots before modifications. Additionally, multiple slashes (such as //) are merged unless the <target> contains multiple slashes too.

Similar directives

Some other directives can also manipulate the request URI.

rewrite changes the entire path and query to a new value instead of partially changing the value.
handle_path does the same as handle, but it strips a prefix from the request before running its handlers. Can be used instead of uri strip_prefix to eliminate one extra line of configuration in many cases.

Examples

Strip /api from the beginning of all request paths:

uri strip_prefix /api

Strip .php from the end of all request paths:

uri strip_suffix .php

Replace "/docs/" with "/v1/docs/" in any request URI:

uri replace /docs/ /v1/docs/

Collapse all repeated slashes in the request path (but not the request query) to a single slash:

uri path_regexp /{2,} /

Set the value of the foo query parameter to bar:

uri query foo bar

Remove the foo parameter from the query:

uri query -foo

Rename the foo query parameter to bar:

uri query foo>bar

Append the bar parameter to the query:

uri query +foo bar

Replace the value of the foo query parameter where the value begins with bar with baz:

uri query foo ^(ba)r $1z

Perform multiple query operations at once:

uri query {
	+foo bar
	-baz
	qux test
	renamethis>renamed
}