Resolved Nginx URL re-writing dilemma

[OlgaKM]

I'm having an issue with Nginx and URL rewriting. By default, the Plesk generated nginx.conf file for each vhost contains the following block:

    location ~ /$ {
        index index.html index.cgi index.pl index.php index.xhtml index.htm index.shtml;
    }

I have a situation where when I receive any requests to http://www.example.com/cat(whatever), they need to be re-written to http://www.example.com/index.php?cat=(whatever). So I added the following block using 'Additional nginx directives':

location /cat {
    try_files $uri /index.php?cat=$uri;
}

Now if I try to request any of the following URLs, this works exactly as expected:

http://www.example.com/cat-test
http://www.example.com/cat/test
http://www.example.com/cat/test/test
http://www.example.com/cat/t

But as soon as I add the trailing slash, I start getting a 404 error:

http://www.example.com/cat/
http://www.example.com/cat/test/
http://www.example.com/cat/test/test/
http://www.example.com/cat/t/

The error log tells that this is because corresponding index.html files cannot be found. Here is one example:

2017/03/21 00:32:49 [error] 25711#0: *20566477 "/var/www/vhosts/example.com/httpdocs/cat/test/index.html" is not found (2: No such file or directory), client: <ip redacted>, server: example.com, request: "GET /cat/testing/ HTTP/1.1", host: "www.example.com"

So it looks like as soon as nginx hits a URL that matches the 'location ~ /$', it abandons looking at the other location blocks. So I have 2 questions here:
1. According to the nginx docs, prefix matches (i.e. location /cat) should be processed BEFORE any regex matches (i.e. location ~ /$). So this is unexpected behavior. Shouldn't nginx look at location /cat first?
2. Commenting out the 'location ~ /$' block in the nginx.conf file fixes the problem. However, this file is automatically generated by Plesk. Plus, I don't want to disable it for all requests, only requests directed to 'http://www.example.com/cat(whatever)'. How can I override this behavior in my 'Additional nginx directives'?

Your help is much appreciated.

 

[OlgaKM]

Additionally, the automatically generated nginx.conf file does NOT seem to follow the guidelines laid out on the nginx "Pitfalls and Common Mistakes" page (!) https://www.nginx.com/resources/wiki/start/topics/tutorials/config_pitfalls/

I've discovered at least 2 issues:
1. The bizarre 'location ~ /$' block that is the cause of my issues. I'm no nginx guru, but wouldn't it be enough to simply place the line 'index index.html index.cgi index.pl index.php index.xhtml index.htm index.shtml;' somewhere within the 'server' block?
2. Use of if statement to redirect non-www traffic to www. The proper solution, according to nginx, is to set up several 'server' blocks with 301 redirects within them. This is a performance issue!

Do these problems get solved in Onyx? Maybe I should just look at upgrading.

 

[OlgaKM]

Ultimately, and with the help of a thread on StackOverflow (How can I setup default directives for all servers in nginx? (Issues with Plesk)), I ended up modifying the default nginx vhost settings. I copied the following files:

/usr/local/psa/admin/conf/templates/default/domain/nginxDomainVirtualHost.php
/usr/local/psa/admin/conf/templates/default/domain/service/nginxSeoSafeRedirects.php

to

/usr/local/psa/admin/conf/templates/custom/domain/nginxDomainVirtualHost.php
/usr/local/psa/admin/conf/templates/custom/domain/service/nginxSeoSafeRedirects.php

Here is the new contents of my nginxDomainVirtualHost.php:

<?php
/**
 * @var Template_VariableAccessor $VAR
 * @var array $OPT
 */
?>

<?php echo $VAR->includeTemplate('domain/service/nginxSeoSafeRedirects.php', array('ssl' => $OPT['ssl'], 'frontendPort' => $OPT['frontendPort'])); ?>

server {
    listen <?php echo $OPT['ipAddress']->escapedAddress . ':' . $OPT['frontendPort'] .
        ($OPT['default'] ? ' default_server' : '') . ($OPT['ssl'] ? ' ssl' : '') .
        ($OPT['ssl'] && $VAR->domain->physicalHosting->proxySettings['nginxHttp2'] ? ' http2' : '') ?>;

<?php if ($VAR->domain->isWildcard): ?>
    server_name ~^<?php echo $VAR->domain->pcreName ?>$;
<?php else: ?>
<?php   if ($VAR->domain->isSeoRedirectToLanding) : ?>
    server_name <?php echo $VAR->domain->asciiName ?>;
<?php   elseif ($VAR->domain->isSeoRedirectToWww): ?>
    server_name www.<?php echo $VAR->domain->asciiName ?>;
<?php   else: ?>
    server_name <?php echo $VAR->domain->asciiName ?>;
    server_name www.<?php echo $VAR->domain->asciiName ?>;
<?php   endif; ?>
<?php   if ($OPT['ipAddress']->isIpV6()): ?>
    server_name ipv6.<?php echo $VAR->domain->asciiName ?>;
<?php   else: ?>
    server_name ipv4.<?php echo $VAR->domain->asciiName ?>;
<?php   endif ?>
<?php endif ?>
<?php if ($VAR->domain->previewDomainName): ?>
    server_name "<?php echo $VAR->domain->previewDomainName ?>";
<?php endif ?>

<?php if ($OPT['ssl']): ?>
<?php $sslCertificate = $VAR->server->sni && $VAR->domain->physicalHosting->sslCertificate ?
    $VAR->domain->physicalHosting->sslCertificate :
    $OPT['ipAddress']->sslCertificate; ?>
<?php   if ($sslCertificate->ce): ?>
    ssl_certificate             <?php echo $sslCertificate->ceFilePath ?>;
    ssl_certificate_key         <?php echo $sslCertificate->ceFilePath ?>;
<?php       if ($sslCertificate->ca): ?>
    ssl_client_certificate      <?php echo $sslCertificate->caFilePath ?>;
<?php       endif ?>
<?php   endif ?>
<?php endif ?>

<?php if (!empty($VAR->domain->physicalHosting->proxySettings['nginxClientMaxBodySize'])): ?>
    client_max_body_size <?php echo $VAR->domain->physicalHosting->proxySettings['nginxClientMaxBodySize'] ?>;
<?php endif; ?>

<?php if ($VAR->domain->physicalHosting->scriptTimeout): ?>
    proxy_read_timeout <?php echo min($VAR->domain->physicalHosting->scriptTimeout, 2147483); ?>;
<?php endif; ?>

    root "<?php echo $OPT['ssl'] ? $VAR->domain->physicalHosting->httpsDir : $VAR->domain->physicalHosting->httpDir ?>";
    access_log "<?php echo $VAR->domain->physicalHosting->logsDir . '/' . ($OPT['ssl'] ? 'proxy_access_ssl_log' : 'proxy_access_log') ?>";
    error_log "<?php echo $VAR->domain->physicalHosting->logsDir . '/proxy_error_log' ?>";

<?php if ($OPT['default']): ?>
<?php echo $VAR->includeTemplate('service/nginxSitePreview.php') ?>
<?php endif ?>

<?php echo $VAR->domain->physicalHosting->proxySettings['allowDeny'] ?>

    location / {
<?php echo $VAR->includeTemplate('domain/service/proxy.php', $OPT); ?>
    }

<?php if (!$VAR->domain->physicalHosting->proxySettings['nginxTransparentMode'] && !$VAR->domain->physicalHosting->proxySettings['nginxServeStatic']): ?>
    location /internal-nginx-static-location/ {
        alias <?php echo $OPT['documentRoot'] ?>/;
        add_header X-Powered-By PleskLin;
        internal;
    }
<?php endif ?>

<?php if ($VAR->domain->active && !$VAR->domain->physicalHosting->proxySettings['nginxTransparentMode']): ?>

<?php if ($VAR->domain->physicalHosting->php && $VAR->domain->physicalHosting->proxySettings['nginxServePhp']
            || $VAR->domain->physicalHosting->proxySettings['nginxServeStatic']): ?>

<?php if ($VAR->domain->physicalHosting->proxySettings['fileSharingPrefix']): ?>
    location ~ ^/<?php echo $VAR->domain->physicalHosting->proxySettings['fileSharingPrefix'] ?>/ {
<?php echo $VAR->includeTemplate('domain/service/proxy.php', $OPT); ?>
    }
<?php endif; ?>

<?php endif; ?>

<?php if ($VAR->domain->physicalHosting->proxySettings['nginxServeStatic']): ?>

    location @fallback {
<?php echo $VAR->includeTemplate('domain/service/proxy.php', $OPT); ?>
    }

<?php echo $VAR->includeTemplate('domain/service/nginxProtectedDirectories.php', $OPT); ?>

    location ~ ^/(.*\.(<?php echo $VAR->domain->physicalHosting->proxySettings['nginxStaticExtensions'] ?>))$ {
        try_files $uri @fallback;
    }
<?php endif ?>

<?php if ($VAR->domain->physicalHosting->php && $VAR->domain->physicalHosting->proxySettings['nginxServePhp']): ?>

    <?php echo $VAR->domain->physicalHosting->proxySettings['directoryIndex'] ?>

<?php if ($VAR->domain->physicalHosting->hasWebstat): ?>
    location ~ ^/(plesk-stat|webstat|webstat-ssl|ftpstat|anon_ftpstat|awstats-icon) {
        <?php echo $VAR->includeTemplate('domain/service/proxy.php', $OPT); ?>
    }
<?php endif; ?>

    location ~ ^/~(.+?)(/.*?\.php)(/.*)?$ {
        alias <?php echo $VAR->domain->physicalHosting->webUsersDir ?>/$1/$2;
        <?php echo $VAR->includeTemplate('domain/service/fpm.php'); ?>
    }

    location ~ ^/~(.+?)(/.*)?$ {
        <?php echo $VAR->includeTemplate('domain/service/proxy.php', $OPT); ?>
    }

    <?php echo $VAR->includeTemplate('domain/service/nginxWordpress.php', $OPT); ?>

    location ~ \.php(/.*)?$ {
        <?php echo $VAR->includeTemplate('domain/service/fpm.php'); ?>
    }

    <?php echo $VAR->includeTemplate('domain/service/nginxWordpressIndexing.php', $OPT); ?>

<?php endif ?>

<?php endif ?>

<?php if (is_file($VAR->domain->physicalHosting->customNginxConfigFile)): ?>
    include "<?php echo $VAR->domain->physicalHosting->customNginxConfigFile ?>";
<?php endif; ?>
}

Here is the new contents of my nginxSeoSafeRedirects.php:

<?php if ($VAR->domain->isSeoRedirectToLanding) : ?>
server {
    <?php echo $OPT['ssl'] ? 'listen '.$OPT['frontendPort'].";\n" : ''; ?>
    server_name www.<?php echo $VAR->domain->asciiName ?>;
    return 301 <?php echo $OPT['ssl'] ? 'https' : 'http'; ?>://<?php echo $VAR->domain->asciiName ?>$request_uri;
}
<?php elseif ($VAR->domain->isSeoRedirectToWww): ?>
server {
    <?php echo $OPT['ssl'] ? 'listen '.$OPT['frontendPort'].";\n" : ''; ?>
    server_name <?php echo $VAR->domain->asciiName ?>;
    return 301 <?php echo $OPT['ssl'] ? 'https' : 'http'; ?>://www.<?php echo $VAR->domain->asciiName ?>$request_uri;
}
<?php endif; ?>
<?php if ($VAR->domain->isAliasRedirected): ?>
<?php     foreach ($VAR->domain->webAliases AS $alias): ?>
<?php         if ($alias->isSeoRedirect) : ?>
server {
    <?php echo $OPT['ssl'] ? 'listen '.$OPT['frontendPort'].";\n" : ''; ?>
    server_name <?php echo $alias->asciiName ?>;
    return 301 <?php echo $OPT['ssl'] ? 'https' : 'http'; ?>://<?php echo $VAR->domain->targetName ?>$request_uri;
}
server {
    <?php echo $OPT['ssl'] ? 'listen '.$OPT['frontendPort'].";\n" : ''; ?>
    server_name www.<?php echo $alias->asciiName ?>;
    return 301 <?php echo $OPT['ssl'] ? 'https' : 'http'; ?>://<?php echo $VAR->domain->targetName ?>$request_uri;
}
<?php         endif; ?>
<?php     endforeach; ?>
<?php endif; ?>

Hopefully, this helps someone!