Information Security

SELinux prevented ruby from reading files stored on a NFS filesytem

While working on a server farm for a client I kept running into some issues with one of the servers. The issue appeared to be a single CentOS Linux server in a cluster of ten CentOS Linux servers configured exactly the same as the other nine CentOS Linux servers was having issues writing to a network storage device. Initially I figured that the CentOS Linux server having the issues had some permission issues with the directory that was mounted to the SAN (Storage Area Network) however after minimal troubleshooting it was verified that the permissions were identical to the other servers. I started looking through other logs on the server having the issue and located some SELinux errors that were noticeably related to the issue at hand. Below I describe where the SELinux error was located, what the specific errors were, and how I was able to resolve the errors on this specific CentOS Linux server.

Technology Insights

Use wget To Download All PDF Files Listed On A Web Page, wget All PDF Files In A Directory

Earlier tonight I was working on a project for a customer that wants to translate the Hebrew Interlinear Bible into English which obviously has been done many times before. This customer however has some translations that he wants to make for himself so I needed to find a Hebrew Interlinear Bible in text or PDF format. I was able to locate the Hebrew Interlinear Bible in PDF format however there was a separate PDF for each chapter in each book which numbers something like 930 different PDF’s. I was able to use the wget command described in detail below to download all of the PDF’s with a single command on my Windows 7 computer.