Recent content on Pace7 Blog
How to connect an iPad Air 2 to a Roland FP-30 digital piano. Problem I encountered a couple of issues which caused the process to be less smooth than I’d hoped: The Roland FP-30 instruction manual says to turn bluetooth on you press the FUNCTION key, and while holding it press “A0” key (first key on the left). However, on my keyboard at least, there is no indication to say that…
Goal: setup my Android handset so that it can connect remotely to hosts on my home network Follow the OpenWRT Wiki guide for general Wireguard setup. Addressing My handset typically doesn’t have IPv6 Internet connectivity, so Wireguard traffic will be over IPv4. However traffic inside the tunnel can be over IPv6. Name IP Home IPv6 ULA 1 fd2c:cfce:c1ce::/48 Home WAN IP 203.123.xx.xx Home LAN…
My TrueNAS Scale server recently started throwing the following zfs module kernel panic 1 on boot: PANIC at space_map.c:405:space_map_load_callback() What follows are the steps I took to retrieve the data from the corrupted zfs pool. Getting setup boot from a Ubuntu 22.04 Live USB disk. Ubuntu (unlike Fedora) supports zfs without needing to compile kernel modules. install the zfsutils-linux…
Australia is about to vote via referendum on whether we should amend the constitution to include a requirement for a body called ‘The Aboriginal and Torres Strait Islander Voice’ which would advise parliament on matters relating to those first people groups (I will refer to those people as ATSI). I will be voting ‘No’. What follows is some of the reasons I’m taking…
Future note to self regarding VSCode/VSCodium I use VSCode on my Windows work machine and VSCodium on my personal Linux machine. Addons Gitlens by eamodio Go by golang Vim by vscodevim Keybindings keybindings.json
I recently stumbled upon the Decent Sampler Plugin and excellent free sample library available from Pianobook. Keen to try out some of the samples, I downloaded the plugin for Linux. There are 3 options for using Decent Sampler (which all come in the download package) - standalone player or VST2 and VST3 plugins. I didn’t have a DAW installed and didn’t really want to use one just to…
tl;dr NetworkManager method=dhcp is deprecated and should not be used. I recently had an issue with a host on my network not getting a IPv6 default route when using DHCP. The host is running Fedora 36 which uses NetworkManager to manage network connections. I wanted the host to have a static IP, but configured via a DHCP static lease rather than manually. I ended up configuring the network…
I recently acquired a Microsoft Surface Laptop 3 and installed Fedora 36 on it. Everything works by default except touchscreen. For touchscreen support you need the surface-laptop kernel. Tips Keyboard + Mouse I found that Fedora Beta was missing drivers for keyboard and touchpad on first boot so I had to use keyboard and mouse attached via USB port. After I ran an update to get latest available…
I recently installed TrueNAS and setup an NFS share for my Linux backups and an SMB share for my wife’s Mac backups. Here are some notes that may be of use to others or my future self 😄 NFS My use case is to mount the NFS share on demand, backup my home directory, then immediately unmount. Create a TrueNAS user with the same UID as the user that will be using the NFS share Under Datasets:
I’m learning to play the drums. Something I’m trialling is split tracks, where the mix of the recording is separated into left and right, with left being only drums and vocals, and right being everything except drums and vocals. This is great except when played through stereo headphones, the mix sounds odd and is uncomfortable to listen to. The solution is to convert the stereo output…
NOTE: work in progress UPDATE Sept 5th 2022: Recent comments by Sam Harris on Trump would suggest that it is Sam Harris who is unhinged! “At that point Hunter Biden literally could have had the corpses of children in his basement, I would not have cared,” – Sam Harris is a brilliant thinker, and has an amazing ability to articulate his thoughts to a broad audience. I should say I’m no…
tl;dr - before going down the 4K path, make sure your graphics hardware is capable of driving your display at full spec. My old faithful Dell U2412 monitor recently started playing up. It is my main ‘work from home’ monitor and I needed to get work done, so I rather hastily found a replacement. I thought to myself “hey, 4K has been around for ages and prices are reasonable so may…
Australian ISP Internode does not officially support OpenWRT. I recently connected HFC (hybrid fibre coaxial) with NBN & Internode. To get it working I needed to tag VLAN 2 on the WAN interface. Using the Luci web interface, navigate to Networks -> Switch and set the dropdown to Tagged next to VLAN 2 under WAN. Then setup the WAN interface like a standard PPPoE with <username>@internode.on.net for…
I just finished watching episodes 1-6 of the BBC historical drama The Last Kingdom. I enjoyed the first few episodes but found myself increasingly unsettled as the eposides went by. Something is very ‘off’ about this story. The TV series is based on the books, The Saxon Stories by Bernard Cornwell, so any criticism of the story and script are going to be primarily with the author. The…
“The Lord’s portion is his people.” – Deuteronomy 32:9 How are they his? By his own sovereign choice. He chose them, and set his love upon them. This he did altogether apart from any goodness in them at the time, or any goodness which he foresaw in them. He had mercy on whom he would have mercy, and ordained a chosen company unto eternal life; thus, therefore, are they his by his unconstrained…
Any technology, no matter how primitive, is magic to those who don’t understand it. - Arthur C. Clarke / Mark Stanley Here are some magical incantations that let me do help me do cool stuff with FFmpeg.
I recently sold a motorcycle via online classifieds. It was a learning experience - more accurately a re-learning experience. I’ve sold motor vehicles privately before and encountered many of the same things - it’s just that I do it so infrequently that I forget the tricks and the traps! What follows are some thoughts and advice to my future self, when next time I go to sell a motor…
UPDATE 2020-03-30 Wireguard 1.0 was included in Linux Kernel 5.6. UPDATE 2018-08-06 Wireguard has been submitted for inclusion into the Linux Kernel source tree. I recently stumbled upon what I think may be the holy grail - a VPN method that is simple to configure, high performance, and (so I’m told) highly secure. Until now my experience of using VPNs was that you could choose any two of…
Geofencing refers to allowing or blocking a connection based on country of origin. Unfortunately, OpenWRT / LEDE does not support geofencing out of the box. The way I’ve worked around this is described below. Shell script I created a shell script /root/bin/ipset-update.sh to pull Maxmind Geolite2 database periodically, and use that to populate an ipset set which I can then reference from…
I recently had the need to transfer a large file from a remote host to S3 but had insufficient local storage to make a temporary local copy. Fortunately AWS command line tools allows for this by reading the piped output of curl as follows: curl https://remote-server/file | aws s3 cp - s3://mybucket/file
I recently had a need to install Linux on a 2014 Mac Mini. Naturally I chose Centos! 😄 I had some trouble finding a straightforward HOWTO to follow, so for the benefit of others wanting to do the same thing, here are the steps I took: download the latest Centos 7 minimal ISO, and transfer that to a USB stick using dd e.g. sudo dd if=CentOS-7-x86_64-Minimal-1708.iso of=/dev/sdb bs=8M insert the…
The article describes how to configure a 6in4 service using your own VPS host. Tunnelling is done using protocol 41 which encapsulates IPv6 inside IPv4. Unfortunately my broadband provider does not offer IPv6. To work around that I tunnel to my VPS host over IPv4 and use IPv6 that way. I could use a tunnel broker such as Hurricane Electric, however their closest endpoint is far enough away that…
At work we have been using AWS elastic load balancers for some time now and found it simple to use and reliable. Unfortunately, the tradeoff for that simplicity is lack of features & control. The main issue we’re facing is the need to implement basic rate-limiting controls on our web frontend to reduce the impact of abuse. I’m actually a little surprised that AWS do not offer some…
I recently ordered a RapidSSL SHA256 CA cert for one of my Zimbra servers. I had all sorts of trouble getting openssl to verify the complete SSL chain - intermediates, plus CA certs. The RapidSSL docs provides a link to an SSL bundle here, however that alone is not sufficient to allow Openssl to completely verify the chain. I downloaded the bundle and put that into file ca_chain.crt, then ran…
EDIT: 2018-03-12, LEDE and Openwrt have merged. References to LEDE here can be substituted for Openwrt. I had a need to run LEDE on x86 hardware. Building a custom LEDE seemed a bit daunting at first, but turned out to be quite straight forward. The build described here is tailored for Qotom J1900 mini PC. Building the custom image I chose to build the LEDE x86_64 image within a Docker container…
I recently went through the exercise of setting up a gateway router for one of my customers. The choices I had to make were two-fold: hardware & software Hardware I wanted to try and find the sweet spot between affordability, processing power, reliability. I could pickup an old desktop PC for next to nothing which would be more than adequate in terms of performance, however I wasn’t…
NOTE: This post applies to Docker < 17.06 By default docker leaves network ports wide open to the world. It is upto you as the sysadmin to lock these down. Ideally you would have a firewall somewhere upstream between your host and the Internet where you can lock down access. However, in a lot of cases you have to do the firewalling on the same host that runs docker. Unfortunately, Docker makes it…
I had a requirement at work recently for our Git repo to be reachable via HTTP. I looked at Gitlab however came to the conclusion that it was probably overkill for our situation. I went with the following setup instead which can be run on the most minimal VM e.g AWS EC2 Nano instance. The instructions were intended for Centos7 however should work without much modification for other distros.…
Australia’s Immigration Detention Situation Australia receives a lot of criticism from all sides, including from within, for its stance on illegal immigration. AFAIK, the current policy for anyone arriving illegally by sea is automatic detention in an offshore facility. The reason for this stance is deterrence - to discourage others from making the same journey. Automatic detention is pretty…
For approximately 100 years (c.1850-c.1950) Australia had a policy of preferring immigrants from Britain and European countries. The origins of the policy are rooted in the gold-rushes of the 19th century, and tensions between the majority white miners (both local and immigrant) and Chinese immigrant miners. In many cases the Chinese miners were more successful than their white counterparts due to…
Today a created a tool for measuring areas on maps: http://pace7.com/utils/maparea/ Map tiles and data courtesy of Openstreetmap.
For anyone who’s interested, I’ve created a contour map of South East Queensland that is suitable for use with Garmin devices (I use a GPSmap 62s). You can download the .img file here. To install, copy the file onto your SD card under the Garmin folder/directory. On your device make sure the map is ’enabled’. The contour map will overlay contour lines over your main map.…
I’ve been using the Gumtree classifieds website a lot recently and have noticed some odd behaviour from people advertising their goods. No photo What’s the deal with so many ads not having a single photo of the item being advertised!? Isn’t it just common sense that an ad with a photo will be far more likely to get views than one without? Are these people really so lazy that they…
At the end of a dinner party recently I got up and offered to help ‘wash the dishes’. Some of the other guests responded in somewhat astonished tone ‘oh, no need - she has a dishwasher!’ (she being the hostess) as if the dishes would somehow put themselves in the machine. This got me thinking, just how much more time, effort, energy, water does a dishwasher actually save?…
With the recent announcement that iOS9 Safari will enable the blocking of web ads, has come much weeping and gnashing of teeth from those on the web who’ve come to rely on ad-based revenue. If Apple deliver on the ad blocking, then many of these ad-supported sites will be severly impacted. I, for one, have no sympathy whatsoever. The writing has been on the wall for a very long time now.
I just configured my home network to use IPv6. My router runs OpenWRT ‘Barrier Breaker’ which supports IPv6, so it was just a matter of switching on and configuring the functionality. Unfortunately, my ISP does not provide native IPv6 so I’m using an IPv6 tunnel courtesy of Hurricane Electric Tunnelbroker service. Configuring my router The 6in4 tunnel Hurricane Electric provide a…
A common scenario when validating form input is to call back to the server to check some detail or other before the final submission. For example, where the user has been asked to select a username, we might choose to verify that the username is available ahead of time. Rather than creating scope variables to keep track of whether or not a form is valid, we are better off using the built-in…
Recently while creating a basic HTTP/HTTPS monitoring app, Pingo2, I started seeing too many open files error. This error was thrown after the app had been running for some time, and I attempted to open a new network connection. Of course, in Unix/Linux network sockets are just files, so this error message actually makes sense in that context. First thing to do was run lsof to see exactly which…
I recently had a need to deploy a t2.micro instance on EC2 running Centos. Unfortunately, there are no official Centos AMIs available that will run on the newer HVM instance types. The AWS marketplace has several 3rd party Centos AMIs that support HVM. I used one of these as a basis for the new install. Centos has the ability to boot up into a VNC server from which a network install can be done.
I’ve just spun up my first install of CoreOS. I found the process a little confusing at times as the doco isn’t terribly clear in places. CoreOS is a work in progress, so doco will improve I’m sure. In the meantime, hopefully this post will be of some help to others. The host machine I used was a standard VPS from my hosting provider running on top of KVM. My hosting provider…
I have one of the original Asus Eee PCs - the 701. I’ve put it to work monitoring the solar array on top of my house. There’s no point in it running all night when the solar panels are idle, so it may aswell sleep too. I found an article on the MythTV wiki which goes into great detail about auto shutdown / wakeup using ACPI….unfortunately none of it worked for me!
By default AngularJS displays URL paths prefixed with a # symbol. This enables backwards compatibility with browsers that don’t support HTML5 history API. The AngularJS guide explains this in detail here To remove the # symbol and display more normal-looking URLs requires the use of html5mode in AngularJS. This is enabled via $locationProvider, for example: app.config(['$routeProvider',…
I recently acquired an Alesis iO2 Portable, 2-channel USB audio interface for hooking up my MIDI keyboard to a soft synth. I had been using my onboard sound card but was finding that latency was unacceptably high. Linux is a rather unique beast when it comes to audio (as with many things) and to the uninitiated can be quite a bewildering experience. Choosing Linux as the basis of a DAW is a bit of…
Using the Gorp package provides the ability for a struct to be populated directly from an SQL backend. Go also provides the ability for this same struct to be populated directly from JSON data. It’s a nice combination but has some gotchas to watch out for. Recently I struck a problem where a column in my database that was NULL was causing me some grief. I was unsure at first how to handle…
There are several possible ways to submit form data to a web server: urlencoded parameter string appended to the URL e.g ?param1=foo¶m2=bar urlencoded parameter string contained in the body of the request, and header set to Content-Type: application/x-www-form-urlencoded multipart form data contained in the body of the request, and header set to Content-Type: multipart/form-data; boundary=...…
I’ve recently replaced the OEM head unit from my 2007 Subaru Forester with an Eonon D2107 head unit. The D2107 is a 2 DIN unit with an 800x480 pixel touch screen, CD/DVD drive, USB + iPod support and Bluetooth. There are several comparable models out there, but I ended up going with the D2107 mainly because it has rotary knobs for volume control and navigation. What follows is certainly not…
It was with great interest that I observed the buzz around the recent Creation vs Evolution debate between Ken Ham and Bill Nye. This is the first time I can recall such a debate taking place where the secular media have taken more than a passing interest. The draw card of course was Bill Nye - the well liked and respected US television personality, public speaker who to many ordinary folks is the…
Another truly beautiful trance track by Norwegian artist Malu Shimmering pacific blue water_s_
I’ve just setup my Fedora19 to use Openvswitch . There are many howtos out there but the ones I read either didn’t cater for RHEL/Fedora or were not reboot safe. My aim was to create a bridge interface with 2 member interfaces:_ an interface for my host _ IP (mgmt0) and the physical NIC (em1). Later, my VMs will also connect to the same virtual switch. Install Openvswitch: $ yum…
Transport for London take money from you even when you DON’T use their service. It has happened to me twice now. The first time I went to catch the tube at peak hour, walked down to the platform, watched as 3-4 full trains went past, then walked out again. I paid several pounds for the privilege. On the second occasion, the particular line I wanted to catch was shut for maintenance.