Category: Web

Upgrade CURL

August 20, 2015

The Yoast SEO plugin in WordPress has started advising users to upgrade curl to the latest version. On CentoOS this can be done easily using the city-fan.org repo here: http://www.city-fan.org/ftp/contrib/yum-repo/ For a CentOS 6 server, here are the steps:

rpm -Uvh http://www.city-fan.org/ftp/contrib/yum-repo/city-fan.org-release-1-13.rhel6.noarch.rpm
yum install libcurl

rpm -Uvh http://www.city-fan.org/ftp/contrib/yum-repo/city-fan.org-release-1-13.rhel6.noarch.rpm

yum install libcurl

404 On sitemap_index.xml With Yoast SEO After Site Migration

August 18, 2015

After moving and renaming a site, we were getting 404 errors for the sitemap generated by Yoast SEO at: http://acme.com/sitemap_index.xml After digging around it turned out the solution was to reset permalinks by going to: Settings -> Permalinks and clicking the Save button without making any changes.

Changing Magento Path

August 18, 2015

Suppose you have a Magento Commerce store at: http://acme.com/store but you want to change the URL to: http://acme.com/catalog There are plenty of articles that give the basics like: https://docs.nexcess.net/article/how-to-change-magento-base-urls.html Basically the steps are: 1. Login to admin, go to Configuration -> Web and change the secure and insecure urls. 2. Move the store/ folder to catalog/ 3. Clear cache and sessions folders with

rm -rf var/cache/* var/session/*

1	rm -rf var/cache/* var/session/*

4. Add a rewrite rule in your .htaccess to send traffic from the old path to the new path:

RewriteEngine On
RewriteRule ^store/(.*) /moulding-catalog/$1 [R=301,L]

1 2	RewriteEngine On RewriteRule ^store/(.*) /moulding-catalog/$1 [R=301,L]

So far so good but we found several additional steps that might be needed. If compilation is turned on then you may need to do:

rm -rf includes/*

1	rm -rf includes/*

Next if you have APC installed in PHP then you may need to restart the web server to clear the APC cache with something like:

/sbin/service httpd restart

1	/sbin/service httpd restart

If you have memcached configured as the cache backend then you’ll also need to restart

How-to Mitigate Bittorrent DDOS Attacks

June 1, 2015

You’ll know that you’re getting hit with a Bittorrent attack when the server slows down and you see log entries referencing:

GET /announce.php

1	GET /announce.php

Here’s a good article about one sysadmin’s struggle with this type of attack: http://blog.carlesmateo.com/2015/01/23/stopping-a-bittorrent-ddos-attack/ There are a number of possible strategies to mitigate this attack: 1. CloudFlare will block but it can take time to move DNS to CloudFlare and activate. 2. Create an announce.php file that returns an error like this:

http_response_code(406);
exit();

http_response_code(406);

exit();

This will use fewer resources then letting WordPress or other CMS return a 404. 3. Block in iptables with a rule like this:

iptables -A INPUT -p tcp --dport 80 -m string --string "GET /announce" --algo bm -j DROP

1	iptables -A INPUT -p tcp --dport 80 -m string --string "GET /announce" --algo bm -j DROP

Not sure how efficient this is on a high traffic web server. 4. Block in Apache config:

<LocationMatch "^/announce(\.php)?.*">
  Order allow,deny
  deny from all
</LocationMatch>

Order allow,deny

deny from all

</LocationMatch>

5. Block with fail2ban as described here: http://shazbert.com/blog/2015/01/24/fail2ban-china-ddos-announce-bittorent/ Note that Plesk 12 has fail2ban built-in so this fix is easy to implement. 6. If traffic is limited to a range of IP addresses

Magento – List Applied Patches

April 26, 2015

You can view a list of patches that have been applied to a Magento site with:

cat app/etc/applied.patches.list

1	cat app/etc/applied.patches.list

You’ll get something like this:

2015-04-17 15:52:07 UTC | SUPEE-5345 | EE_1.12.0.2 | v1 | 2d36f61cf684ed26286b6d10307fcb99dd47ff02 | Thu Feb 5 19:39:01 2015 +0200 | v1.12.0.2..HEAD
patching file app/code/core/Mage/Admin/Model/Observer.php
patching file app/code/core/Mage/Core/Controller/Request/Http.php
patching file app/code/core/Mage/Oauth/controllers/Adminhtml/Oauth/AuthorizeController.php
patching file lib/Varien/Db/Adapter/Pdo/Mysql.php

2015-04-26 11:51:44 UTC | SUPEE-1533 | EE_1.12 | v1 | _ | n/a | SUPEE-1533_EE_1.12_v1.patch
patching file app/code/core/Mage/Adminhtml/Block/Dashboard/Graph.php
patching file app/code/core/Mage/Adminhtml/controllers/DashboardController.php