Technology Insights

WordPress Image Upload Error: Unable To Create Directory, Is Its Parent Directory Writeable By The Server?

I haven’t posted to my personal WordPress blog in months because I have been busy writing QD articles and working on the QD Tools section. So I got a comment posted to my personal blog tonight that inspired me to finally get back to making a blog post on the WordPress site that houses my personal blog. During the post I wanted to upload an image of my daughter which I typically do using the “Add an Image” button located in the WordPress admin “Add New” post interface. The “Add an Image” button by default allows two different methods of uploading images via your web browser which include the Flash Uploader and the Browser Uploader. On Question Defense I use a modified version of the Browser Uploader however on my personal WordPress blog I always have used the Flash Uploader. Tonight when I attempted to add a post I received an error which I initially thought to be related to permissions however that was not the case as I explain below along with steps to resolve the issue.

Technology Insights

ActionView::TemplateError (protected method filter_parameters called for #)

I assisted in looking into a Rails issue earlier with a friend. After making some modifications to some Ruby code he had an issue receiving exception emails which were generated by Rails. The rails plugin being used to accomplish this is called exception_notification and resolving the problem was simple. As you will see below instead of upgrading the entire plugin a couple lines in one ruby file were modified, the web server restarted, and the exceptions again started functioning properly. Below I display more of the error and the modifications made to resolve the error.

Technology Insights

Use .htaccess To Redirect One Domain To Another Domain

I have been using a WordPress plugin for awhile called Pretty Link Pro which provides a ton of awesome features including a link shortener such as tinyurl.com. When using the URL shortener you can actually configure Pretty Link Pro to use a different domain which would be a benefit if your URL is long similar to www.question-defense.com. I have been using link.as so instead of providing shortened links such as http://www.question-defense.com/1ce I can provide links such as http://link.as/1ce which you can see is a lot more user friendly when providing links to others. One thing I wanted to ensure was the fact that Google was not crawling content on the http://link.as URL which is possible simply by Google finding the shortened links on places like Twitter. Below I describe a .htaccess modification that will redirect any traffic to one URL to another while including any trailing text.

Technology Insights

VSFTPD Error: GnuTLS error -9: A TLS packet with unexpected length was received.

I was tasked with configuring VSFTPD to allow SFTP or FTPES (FTP over explicit TLS/SSL) tonight for a client. The configuration already had regular FTP working which I verified using FileZilla as an FTP client. I was able to login and transfer files in both directions to and from the server. Next I verified that SFTP worked without issue and I was able to also transfer files in both directions using SFTP. For FTPES I had to make some changes and once I did make the changes I was still getting an error when attempting to do a directory listing using FileZilla. Below I describe the initial changes I made to vsftpd.conf, the errors I received attempting to connect with FTPES, and the way I resolved the problem.

Technology Insights

Use Wireshark And DD-WRT Router Firmware To Imitate Port Monitoring On A Router Switch Port

Earlier today I needed to find the quickest and easiest way to monitor all traffic to and from a specific device on my network. The goal was to see how much bandwidth based on a specific amount of time that the device was using. My initial hope was that I could configure port monitoring on my WRT54G running DD-WRT firmware however I quickly found out this is not an option. I eventually settled on adding a couple iptables commands that would send all traffic destined for or sourced from a specific IP address to another IP address. Follow the directions below to add the iptables commands to a router running DD-WRT firmware and then to capture the traffic on a computer running Wireshark.