I Am Justyn

I fix things

Mar 5, 2017 - 2 minute read - Comments - Scripts

Monitoring PiHole with Telegraf and Influxdb

I recently installed Pi-hole on a spare Raspberry Pi 3. Pi-hole essentially blocks most advertisements from devices on a network, by running dnsmasq with a custom set of hosts to block.

Before Pi-hole, I was using dnsmasq with a hosts list generated by a bash script combining a few other hosts files from the internet. My solution worked, but I didn’t put much effort into it, and it wasn’t the easiest thing to maintain.

Pi-hole definitely has more polish to it, and includes a nice web interface for monitoring, logging, and some configuration. One of the first things I noticed was that the dashboard displays a few stats on the front page. Obviously that meant I needed to export the same stats to InfluxDB to graph in Grafana later. This is my quick solution for doing exactly that.

Jan 19, 2013 - 2 minute read - Comments - Plesk Linux

Rebuild missing SSL certificates from Plesk database

I’ve had to deal with errors similar to this occasionally on Plesk servers: root@cent:# apachectl -t Syntax error on line 55 of /var/www/vhosts/domain.com/conf/13449678050.31729500_httpd_ip_default.include: SSLCertificateFile: file '/usr/local/psa/var/certificates/cert-sFD3Ys' does not exist or is empty Probably the #1 reason I see this is when we’re doing migrations from one Plesk machine to another. Restoring Plesk-created backups can also cause it sometimes. Regardless of the reason, if the certificates exist in the psa database – they can be re-created easily through ssh.

Aug 8, 2011 - 5 minute read - Comments - Linux

Automated off-site Linux Backups using Duply and Duplicity

Off-site backups are important, and even though I know this, I rarely implement them in my own servers. Lately, I’ve been setting up rsnapshot to do hourly and daily backups locally(to the same server), and I only do manual backups to remote servers occasionally. I decided to install duply on all of my servers/virtual machines(that I care about) and have them back up to a single backup server. This backup server will also do daily encrypted backups to Amazon S3, effectively giving me 3 redundant layers of backups.

May 8, 2011 - 4 minute read - Comments - Linux

Xen file-based vs LVM-based disk images (benchmarks)

I’ve been messing around a lot with Xen lately and have seen several different articles and forum posts debating the advantages over using file-based disk images, like /mnt/xen/VM01-disk.img, versus giving the VM direct access to a LVM partition. So, I ran a few simple tests on my own to determine what would be best for my machine.

Dom-0 is using four 1.5tb 7200rpm seagate drives in a software Raid-10, /dev/md2. Both Dom0 and DomU have 1gb of ram and are using ext3. Xen is using mainly default settings with the default scheduler.

Feb 13, 2011 - 5 minute read - Comments - Scripts

Create Your Own URL Shortener

I don’t really pay attention to twitter that often,but I did notice more and more people are starting to use personalized url shorteners. There’s a lot of free services out there you can use, but if you have somewhere you can host a simple php script, why not make your own?

I ended up buying iamj.us/tyn, and that’s what I’m going to set this up on. If I wanted to make things shorter, I could take off the /tyn but then I dont think it’d make as much sense. http://iamj.us/tyn11l redirects back to this page, for example. If you need help picking out a short domain name, try out domai.nr.

To create my own shortener, I decided just to use php’s base_convert function which will convert to and from bases 2-36. For a personal url shortener, you shouldn’t need more than base 36. I did end up having to write a base 62 converter class for sh0tz so that I can keep urls short, but that’s another post another time.

Note: This article is kind of old now, and I’ve since learned some better ways to accomplish everything mentioned here. I plan on making a follow-up post to this soon. In the mean time, this still works and I still use it as well.

Sep 29, 2010 - 2 minute read - Comments

Installing and Updating WordPress via SVN

I have quite a few WordPress installations that I semi-manage on my server, and just recently realized how time consuming it is everytime a new version comes out. WordPress does let you update it to the newest version directly from the admin interface which is definitely nice, but if you have several installations of WordPress you aren’t going to want to log in to every single one of them and click that update button.

One solution, and the one I decided on for now, is to use Subversion. Ever since 1.5, WordPress has been using subversion for its version control so of course they allow public read-only access to the subversion repository. Whether you are already familiar with subversion or not, it is relatively easy to install WordPress using svn and then keep it up to date as well.