Hi all, been a while since I’ve posted anything, I’ve recently picked up myself a new camera. Got a pre-owned Canon EOS 700D, its been a while since I’ve had an SLR but I quite fancy another go.

So, having a play I thought I’d do a little video showing the greenhouse and aquaponics. 2nd proper year of the aquaponics in its current location, its doing well.

https://www.youtube.com/watch?v=tIQq6H6sceg

Many moons ago, I used to brew my own beer. Nothing spectacular just a 25l fermentation bucket with a ready made kit. Since we moved house I’ve always had the plan of hiving off a section of the garage dedicated to beer making, the problem with that is my garage has literally been full of stuff. Now that most of the renovation projects are complete (nearly 5 years later) there’s room in the garage and I can now start brewing again.

As part of my interest in aquaponics I’ve always intended to enable some kind of electronic monitoring, various thoughts on what to monitor and how have been in my head for a while. Recently I’ve been wondering if the temperature levels of the water are high enough so this was as good a place as any to start.

An Arduino was my obvious choice to start with, I built various circuits but soon decided that I wouldn’t be running Ethernet anywhere near and that kind of ruled it out with regards to re-using existing kit. I decided to use one of the nodeMCU devices I’m halfway through a project on (I’ll just buy another couple eventually).

Thought I’d post a quick progress report on the aquaponics setup as the build pretty much complete and the growing has commenced. I left the last post where I had a lovely clean tank and had just introduced 20 goldfish. About a week later I introduced a further 20 and I’m happy to say that around 3 weeks on the fish are thriving, initially they seemed to cower in a corner but are making full use of the space.

A few weeks ago, a friend of mine and I were sharing YouTube videos around water harvesting, hydro electricity generation and the like. As the usual YouTube journey does, I ended up going off on a tangent and watching a video on aquaponics. I found it really fascinating so started looking deeper and deeper, and finally decided to give it a go. I’d always planned on getting a greenhouse for our new garden and a couple of planter boxes and growing veg but this looked great.

A while ago I bought one of the Maplins weather stations, just for fun really no plans with it. The device came with a pole to which several sensors could be attached: temperature, humitidy, wind speed, wind direction and rain level. The other important bit in the box was the control station, which is a large LCD screen based output for the information which is gathered in the sensors, it also gives an attempt at forecasting. Areas of the screen are pressure sensitive which allows for a touchscreen style interface for changing views etc.

I wrote a post a while ago covering the use of Monit to monitor services running and the use case I covered was to ensure these services restarted on failure. While a useful feature of Monit, it seems to be now a little redundant with SystemD having a built in restart feature.

Same use case where MySQL (or MariaDB in this case) is being killed by Apache’s oom killer.

I first copied the original systemd file associated with Mariadb from /usr/lib/systemd/system/mariadb.service to /etc/systemd/system/mariadb.service

Something I’ve been meaning to do for a while is look into the possibility of using 2 factor authentication, or 2FA, with SSH connections. This would add a much needed level of security to servers I host out in the wild.

Here’s how I did it:

The Google Authenticator mobile app used to be an open source project, it isn’t any more but the project has been kindly forked and looked after by Red Hat under the guise of the FreeOTP project. The first step is to download the app, which is available for Android and iOS there is even a Pebble project in the works. https://fedorahosted.org/freeotp/

A valuable tool I have been using for many years is etckeeper, it works by essentially turning your /etc directory into a git repository.

This is a fantasticly useful set of tools as any configuration changes can be logged and also reverted quite easily. Install and setup is exeptionally easy too!

Packages are available for most distributions, but my scenario (Fedora,CentOS,RHEL) was:

yum install etckeeper

Once the package was installed an initialisation must be performed: