Pither.com / Simon
Development, systems administration, parenting and business

Variable substitution in docker-compose .env env-files

I was recently given an existing set of files to create a collection of Docker containers via the docker-compose tool. Unfortunately this rapidly led to some annoyances with variable substitutions within a docker-compose (.env) env-file. This is the kind of thing I mean:

DOMAIN=example.org
EMAIL=admin@${DOMAIN}

The problem was that they don't seem to be supported in docker-compose 1.25.5 (as shipped …

Tags: technology

Redhill technology events: Red Sprite

Since March, Neil (of Terzo Digital) and I have been running a relaxed and free technology evening each month.

We created Red Sprite as a way to give back to the local community while also having fun. The events are intended to educate as well as entertain; with a variety of formats and topics being covered.

Having passed our …


Choosing a live chat application

I want to add a line chart option to PaTMa, both for enquiries and pre sales questions as well as support for subscribers.

But it seems there are a lot of live chat options out there at the moment. So, as much as a record for myself as anything, I thought I'd document the ones I've considered and what …

Tags: technology


LXD on LVM - thinpool setup

No matter what I tried I couldn't convince "lxd init" to create, or configure an existing, LVM thinpool for it's use!

So I ended up doing it rather more manually...

Basic requirements before getting started at all:

apt install lxd thin-provisioning-tools

Then create a thinpool, in this case using all of the remaining space on the "local" volume group:

lvcreate …


Custom/manual Ubuntu install via IPMI (on OVH hosting)

I recently spent a while working out how to do a completely custom install on a physical machine rented from OVH, making use of the IPMI access they provide. I thought I'd document it for future reference. So here's how to perform a custom/manual Ubuntu install via IPMI on OVH hosted hardware.

Disable OVH monitoring

First up is an OVH …

Tags: technology

Request Tracker - Precedence: bulk

I use Request Tracker as the ticketing tool for support enquiries to my web hosting company and happened to notice (while looking at email headers for something else) that it's sending out ticket emails with the header:

Precedence: bulk

I can understand why this is a reasonable default, especially as RT is often configured to send automatic acknowledgement and status …

Tags: technology

Wordpress - my essential plugins

If you've ever hosted a website, especially a blog, I'm sure you've considered Wordpress as the potential software to use.

Despite this personal blog not using Wordpress, I do use it for a few others, where I just wanted to get up and running really quickly with a pretty standard set of features. That was exactly what I wanted …

Tags: technology

Podcasts I hear in 2018

It's been over three years since I last wrote about the podcasts I listen to, so I think it's past time for a revisit.

Looking back at my list from 2014, I think the only ones I've stopped listening to are those that have stopped publishing content. I've certainly added a few more to my regular listening list though, especially …




Testing a new boot configuration

This approach is useful for testing all sorts of changes in boot setup without actually risking a real reboot. Whether you're about to remove a hard disk, just want to test RAID with disk failures, have installed a new boot loader or just changed the configuration; this can help provide reassurance that your remote server will come back when you …



Podcasts I Hear

Once upon a time, a time that feels a very long time ago but I think was only a couple of years in the past, I spent some time regularly commuting to one of my clients.

Armed with a smart phone and headphones I discovered audio books and podcasts as an excellent way to make use of this time. I …


Design a Formula 1 Helmet

One of the projects that has been filling, a little too much at times, my recent non-parenting hours is now accepting entries.

The site is an addition to the Infiniti Formula 1 press site to provide competitions for people to design Formula 1 helmets (or a small non-advertiser section of them) that Sebastian Vettel will wear later in the season. …


The Best (Android) Phone

I have found the next Android phone that I'd like to buy. In fact, I have paid for the next Android phone that I want to have. However there is no guarantee it will ever arrive!

I need about 30,000 more people to also place an order for what I think would be the perfect new phone, otherwise it will …


Grails vs Django

Update: I revisited this Grails vs Django discussion in Jan 2015.

Before I met Grails I had spent several years writing my web applications in Perl, including work on two different in-house frameworks to try to make life easier! I also dabbled a little with Ruby on Rails but for some reason it just didn't stick (I think I prefer …



ssh SOA error

Logcheck on a couple of Debian Squeeze servers has been sending me some errors for a while and I finally got time to track down the cause. The errors looked like this:

Aug  5 07:00:56 build1 ssh: getaddrinfo*.gaih_getanswer: got type "SOA"

It turns out that this is due to some scripted outbound ssh connections (in this case Jenkins polling a …