How to debug .htaccess redirects?

[An147]

Hi! I'm relatively new to WHM and I have a problem, I need to eliminate 301 redirects chain I have now.
E.g. I need to point "http://www.example.com////SHop///" to "https://example.com/shop/" in one 301 redirect (it's possible, I did it a lot of times but on shared/VPS hostings).
So I need to make HTTP to HTTPS, non-www, replace all characters to lowercase, eliminate multiple slashes and add trailing slash if it's absent.

I have some Rewrite in .htaccess, but I don't know how can I debug it.
I used OpenLiteSpeed before, and it has rewrite logging.
I tried enable logging with LogLevel debug for example.com domain using this manual, but it doesn't output redirection-related things.
So my question is more about "where I can see Apache rewrite logs?"

I'm using WHM v100.0.5 on CentOS v7.9.2009.
Server Version: Apache/2.4.52 (cPanel) OpenSSL/1.1.1m mod_bwlimited/1.4
Server MPM: prefork

 

[An147]

Ok, I found solution here, sorry for being so dumb:
https://httpd.apache.org/docs/2.4/mod/mod_rewrite.html

I needed someting like

LogLevel alert rewrite:trace3

in my conf file, not using RewriteLogLevel directive.

I'm wondering now where do some default rewrite rules come from, but the initial topic question is answered

 

[cPanelAnthony]

Hello! I am happy you found a solution. Which redirect rules were you curious about?

 

[An147]

Hello! I am happy you found a solution. Which redirect rules were you curious about?

Hi Anthony! Thanks for the reply.

I want to know where does some default redirects come from. Now I have basic WHM installation (I did not touch apache, except memcached installed).

I have this configuration in .htaccess file:

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond expr "tolower(%{REQUEST_URI}) =~ /(.*)/"
RewriteRule [A-Z] %1 [R=301,L]

# Below is the default W3 Total Cache and Wordpress config (just for your information). Also PHP handler is just at the end (is it ok?)

# BEGIN W3TC Browser Cache
<IfModule mod_mime.c>
    AddType text/css .css
    AddType text/x-component .htc
    AddType application/x-javascript .js
    AddType application/javascript .js2
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</IfModule>
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        AddOutputFilterByType DEFLATE text/css text/x-component application/x-javascript application/javascript text/javascript text/x-js text/html text/richtext text/plain text/xsd text/xsl text/xml image/bmp application/java application/msword application/vnd.ms-fontobject application/x-msdownload image/x-icon application/json application/vnd.ms-access video/webm application/vnd.ms-project application/x-font-otf application/vnd.ms-opentype application/vnd.oasis.opendocument.database application/vnd.oasis.opendocument.chart application/vnd.oasis.opendocument.formula application/vnd.oasis.opendocument.graphics application/vnd.oasis.opendocument.presentation application/vnd.oasis.opendocument.spreadsheet application/vnd.oasis.opendocument.text audio/ogg application/pdf application/vnd.ms-powerpoint image/svg+xml application/x-shockwave-flash image/tiff application/x-font-ttf application/vnd.ms-opentype audio/wav application/vnd.ms-write application/font-woff application/font-woff2 application/vnd.ms-excel
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        Header unset Set-Cookie
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# BEGIN WordPress
# The directives (lines) between "BEGIN WordPress" and "END WordPress" are
# dynamically generated, and should only be modified via WordPress filters.
# Any changes to the directives between these markers will be overwritten.
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

# php -- BEGIN cPanel-generated handler, do not edit
# Set the “ea-php74” package as the default “PHP” programming language.
<IfModule mime_module>
  AddHandler application/x-httpd-ea-php74 .php .php7 .phtml
</IfModule>
# php -- END cPanel-generated handler, do not edit

So, for now "http://www.example.com///SHop///" going through this redirection chain:
"http://www.example.com///SHop///" => "http://www.example.com/shop/" => "https://example.com/shop/"

I just don't understand where the slashes stripping coming from in the first redirection, the 2nd one seems like a Canonical Hostname or something like that, which is related to apache httpd.conf file as I guess.
I have a lot of commented out rules in my .htaccess too - if I uncomment them, I have either 400 bad request in the end, or just "Too many internal redirects error":

RewriteEngine On

#just before all other rules listed above

# RewriteCond %{HTTPS} !=on [OR]
# RewriteCond %{HTTP_HOST} www\.example\.com [NC]
# RewriteRule ^ https://example.com%{REQUEST_URI}[R=301,PT]

# RewriteCond %{REQUEST_FILENAME} !-f
# RewriteCond %{REQUEST_FILENAME} !-d
# RewriteCond %{HTTPS} off
# RewriteRule ^ https://example.com%{REQUEST_URI}[R=301]

# RewriteCond %{HTTP_HOST} www\.example\.com
# RewriteRule ^ https://example.com%{REQUEST_URI}[R=301,L]


# Rule 1: remove multiple leading slashes (directly after the TLD)
# RewriteCond %{THE_REQUEST} \s/{2,}
# RewriteRule (.*) $1 [R=301,PT]

# Rule 2: remove multiple slashes in the requested path
# RewriteCond %{REQUEST_URI} ^(.*)/{2,}(.*)$
# RewriteRule (.*) %1/%2 [R=301,PT]

#if I uncomment any of these, the issues happens

Also I'm tried to use [PT] flags instead of [L] - coz I have mod_alias and mod_userdir installed and read that sometimes I need PT flag, but it seems it become even worse with it. Now I feel myself a bit like a code monkey ;D

Is there a way to move all redirects either in the place where it occurs for every domain registered in WHM (that will be fine in my case),or just disable any redirects and put them all in .htaccess (like I did when I was working with some shared hostings)?

 

[cPanelAnthony]

I am not seeing any redirects that cPanel would put in place by default. It might be worth using auditd to determine what might be writing to the .htaccess file.

How to use auditd