Gravity Cars and a Nerdy Derby Track

I recently had the opportunity to create the Gravity Cars class for the Crucible’s Youth Program. As part of that work, I created a race track based on the Nerdy Derby design.

Creating the track was a fair amount of work and involved implementing the design in Autodesk Inventor based on the original PDF from the folks at Nerdy Derby, creating tool paths for a ShopBot Alpha to cut out the pieces, gluing the segments together and assembling the track. But it was most definitely worth the time.

All files for the project can be found on my github repository.

 

Nagios Monitoring of Directories

I had a recent occurrence at work that caused me to look around for a tool to monitor a directory for any changes made. Since there didn’t seem to be anything out there, I created a check called dirchanged. It looks at all the files in a directory and creates an sha256 has of the names and contents of the files. That hash is compared to a known value to determine if there have been any changes made.

There are a couple of issues with this check specifically that it doesn’t look into subdirectories and that the hash for comparison is passed on the command line from within the Nagios configuration files. I think the first issue will be fixed soon enough w/ a flag to indicate if the directory tree is to be traversed. The second issue is more cumbersome in that the hash value has to be stored somewhere. I’m not yet certain that putting it in the Nagios configuration files is better than putting it somewhere on the target file system. From the security standpoint, having the check not stored on the target file system is better, much less chance of it being changed by bad guys.

I’ll let it run for a while and see how it behaves and if changes are warranted.

Down, moved and back once again

I didn’t realize that the site was down, that’s not good.

I discovered this when I started to migrate to a new server on Digital Ocean. I like their service level, server configurations, and very reasonable costs. Plus the fact that they run everything on SSD makes it all nice and blazingly fast ;-)

With the site now fully migrated, hopefully things will be back to normal. And that I’ll be posting again. So many ideas and projects to share! And I need to get a Nagios monitor in place to let me know the next time the site goes sideways.