I recently got a call from a friend who has a library of thousands of PDF documents. He wanted to know there was a such thing as a personal search engine that could index his library of documents, and allow full text search inside of them.
I have a giant document library too, including PDF documents, Office documents, source code, email and so on. I decided I needed one too, and it should be based on Elastic Search.
The net result of the weekends work is "kSearch", a personal search engine. kSearch include a threaded file system indexer, automatic maintainence of the search index as the file system changes, and a web search UI.
Home automation is coming into the mainstream a with recent offerings from the big tech companies, and I'm interested in it too. I've had a number of home automation controllers, most recently an H3 Pro SEL from HomeSeer.
So, I decided to import home status information into InfluxDB and graph it. The first step was getting the information from HomeSeer. There is a JSON-over-HTTP API, but no existing Java client. So, a simple HomeSeer H3 API client in Java was written: hsclient.
The next step was getting the data into influx. The best way to do this would be to write a Telegraf plugin. However, I wanted a chance to learn a little more about Java closures and lambas, so I wrote hsinflux a threaded command-line app which connects to HomeSeer on a schedule, downloads the device status data and drops it into InfluxDB. hsinflux is here.
The net result, with Grafana, is the ability to see my house temperatures, humidity, door and window status, and thermostats. Here are some examples.
House temperatures this week on 5 minute intervals
At the time of writing, its -17C outside, and my server room temperature is showing a steady decrease, down to -6C. The increase on the far right is the result of opening the server room door to get some warm air from the house.
And since I have a TSDB, why not record the time it's taking to collect data from HomeSeer?
Since I can, I'm also querying battery charge on the devices that have batteries. It's not an interesting graph, but down the road I can use Grafana to alert me when the batteries need to be changed.
Overall, a great opportunity to become familiar with the technologies. Once the data is in Influx, building arbitrary graphs to visualize data is both simple and powerful. The graphs I've built are simple, however for IT professionals wanting insight into complex infrastructure, tools such as Influx and Grafana represent a step change in visibility and analysis.
From an operational perspective, TSDB's give DevOps engineers an opportunity to answer a question we've been trying to answer for decades:
What changed the hour before it crashed? The week before it crashed? The month before it crashed?
I've recently become very interested in blockchain, and that, naturally led me to Ethereum and Bitcoin. From there, I got a little interested in online trading, but since I prefer not to have to think about trading, I started thinking about a trading bot. Part of the work I needed to do was write a Java API for Qaudrigacx. The API is here and is free to use under the GPL v3 terms.
I've been using FreeBSD jails for a while, and was looking for a simple way to create jail filesystems. After some reading, I came up with this simple script which creates full FreeBSD filesystems. The filesystem can then be used via jail.conf.
I've been interested in OS development for a while, and now have a prototypical ARM OS on my private source tree. For that I used gcc-arm-embedded, which worked quite well. However, as time went on, i became interested in building my own tool chains. I started with this list of requirements
An up-to-date C/C++ compiler, such as gcc or clang
The targets I prefer to cross compile from are OS X and FreeBSD. I prefer to cross-compile to i386, arm, sparc and mips targets
I ended up with two shell scripts, one for GCC/Binutils/Make and one for Clang/Binutils/Make, which download and install the latest GCC/Clang/Binutils and create a fully operational toolchain for the target of my choice. You can find them here:
I've been trying forever to get a mobile IPSec connection up between my OS X laptop and pfsense. Finally, thanks to this outstanding blog post, it works. I'm especially excited that it works with the default OS X and Android VPN clients.
My pfsense config closely mirrors the one specified by Mike Murray
Key Exchange version: Auto
Internet Protocol: V4
Interface: <my ISP>
Authentication Method: Mutual PSK + Xauth
Negotiation Mode: Aggressive
My identifier: My IP Address
Peer identifier Distinguished Name: <my vpn name>
Pre-Shared Key: <my key>