Unable to remove empty parameters in url using context path in Location tag in apache http server - mod-rewrite

Question

Unable to remove empty parameters in url using context path in Location tag in apache http server
Without context path setting, empty parameters are being removed correctly as expected,
Below is the example with context path, where empty parameters are not removed (Problem statement)
<Location /reports/>
LogLevel alert rewrite:trace8
RewriteEngine On
RewriteBase /
ProxyPass http://1.2.3.4:3000/
ProxyPassReverse http://1.2.3.4:3000/
RewriteCond %{QUERY_STRING} ^(.+?&)?[^=]+=(?:&(.*))?$
RewriteRule ^/reports$ /reports/?%1%2 [R=302,NE,L]
</Location>
Below is the example without context path, where empty parameters are removed as expected (But the final solution needs to work with a context path)
<Location />
ProxyPass http://1.2.3.4:3000/
ProxyPassReverse http://1.2.3.4:3000/
RewriteEngine On
AllowOverride All
RewriteCond %{QUERY_STRING} ^(.+?&)?[^=]+=(?:&(.*))?$
RewriteRule ^ %{REQUEST_URI}?%1%2 [R=302,NE,L]
</Location>
How do I remove the empty parameters from the URL with the context path setting in the location?

Answer 1

<Location /reports/>
:
RewriteEngine On
RewriteBase /
:
RewriteCond %{QUERY_STRING} ^(.+?&)?[^=]+=(?:&(.*))?$
RewriteRule ^/reports$ /reports/?%1%2 [R=302,NE,L]
</Location>
There are several issues here...
Your <Location> block matches /reports/ (with a trailing slash), but your RewriteRule pattern ^/reports$ omits the trailing slash, so it will never match.
<Location> blocks are merged very late and in this context the RewriteRule pattern matches against the absolute filesystem path, not the root-relative URL-path.
So in order to match the request, the RewriteRule pattern should be like /reports/$ instead to allow for the absolute filesystem path, eg. /path/to/document-root/reports/. In other words:
RewriteRule /reports/$ /reports/?%1%2 [R=302,NE,L]
Or, omit the path component of the RewriteRule pattern altogether (eg. simply ^), unless you must only match /reports/ and not /reports/<anything>.
HOWEVER, you shouldn't use mod_rewrite directives inside a <Location> block to begin with. From the Apache 2.4 docs on the RewriteRule directive:
Although rewrite rules are syntactically permitted in <Location> and <Files> sections (including their regular expression counterparts), this should never be necessary and is unsupported. A likely feature to break in these contexts is relative substitutions.
The RewriteBase directive is not being used here. (But it is not supported/not required outside of a directory context.)
The RewriteRule pattern and the <Location> directive are performing the same check. Move these mod_rewrite directives outside of the <Location> container and have them directly in the <VirtualHost> container (or server context). For example:
LogLevel alert rewrite:trace8
RewriteEngine On
RewriteCond %{QUERY_STRING} ^(.+?&)?[^=]+=(?:&(.*))?$
RewriteRule ^/reports/$ /reports/?%1%2 [R=302,NE,L]
<Location /reports/>
ProxyPass http://1.2.3.4:3000/
ProxyPassReverse http://1.2.3.4:3000/
</Location>