Ian's Notes

If the KLM app or website indicates that you need to add your passport and visa to the app, it might be confusing what exactly is expected when you’re asked to enter the visa details.

If you’ve just kicked off your PostgreSQL replication and immediately see errors like the following in your primary’s log: STATEMENT: CREATE_REPLICATION_SLOT "pg_1860137326_sync_1860136532_7292029644802025672" LOGICAL pgoutput (SNAPSHOT 'use') ERROR: repl…

“So much universe, and so little time..” – Terry Pratchett Note: if you need the upgrade steps for version 14 to 15, you can find them here.

“This isn’t life in the fast lane, it’s life in the oncoming traffic.” – Terry Pratchett If you see the following error in your Veeam agent CLI or your veeamsvc.log file: [03.11.2023 15:13:34.448] <140511610394304> lpbcore | Checking blksnap snapshot erro…

If, for some reason, your Linux installation is missing an /etc/ssl/certs/dhparam.pem file, you may encounter an error along the following lines in your web server logs (this example is from Nginx): No such file or directory:calling fopen(/etc/ssl/certs/d…

The following CSS will keep the header row of a table visible even if the user scrolls down past the point where it would ordinarily disappear (similar to freezing the top row in Excel): /* Freeze top header row */ table th { position: sticky; top: 0px;

We’ll use the inputs.exec Telegraf plugin to run our megaraidsas-status or megacli commands and parse their output as a single boolean value, indicating whether all RAIDs are healthy.

If you have a folder somewhere in iCloud which is showing “Waiting to upload” and the usual caveats (on battery, etc.) do not apply, the easiest solution is to exclude that item from syncing with iCloud and then re-add it.

If you’re using multiple databases and routers in a single Django project, and you’re combining this with dynamic meta queries, it is inevitable that you’ll — at some point — need to find out to which database a model class or instance belongs.

“One of the poets, whose name I cannot recall, has a passage, which I am unable at the moment to remember, in one of his works, which for the time being has slipped my mind, which hits off admirably this age-old situation.” – P.G.

So the extension is apparently installed already, but not usable.

TL;DR ln -s "/Users/$(whoami)/Library/Mobile Documents/com~apple~CloudDocs/" iCloud The long version If you use the terminal often, it is convenient to have a soft link between your home folder and your iCloud folder on Mac.

Most languages support the \p{L} class to match any alphabetical character, essentially a superpowered version of the classic [a-zA-Z].

I’ve recently experienced a case of very high CPU usage on a production server, and very slow inbound network throughput on any transfers.

To return multiple values, surround them with square brackets: function multiReturn() { return [1, 2, 3, 4]; } To receive those values when calling the function, use the same notation: [a, b, c, d] = multiReturn(); As a bonus, if you have an array cont…

This is a known issue, which has never been addressed in the Python stdlib.

“This idea that there is generality in the specific is of far-reaching importance.” – Douglas R.

The Django inspectdb command allows you to make use of an existing database structure to generate a models.py file, but the command produces a number of incompatibilities.

“It’s not worth doing something unless someone, somewhere, would much rather you weren’t doing it.” – Terry Pratchett In any Django app, there is a models.py file which contains a list of the models registered to that application, each corresponding to a…

This requires configuration on both sides, from the perspective of the client instance, and the server instance.

This may be needed if you’re importing data from an external source, such as a CSV file: ALTER TABLE my_table ADD COLUMN id SERIAL PRIMARY KEY; SERIAL maps to INT, and BIGSERIAL maps to BIGINT, so you can use either depending on the anticipated size of y…

If you’ve run an in-place upgrade from DSpace 6 to DSpace 7 and you encounter this issue on the frontend trying to communicate to the backend, it is likely that your DSpace 7 backend is running on Java 8 instead of Java 11.

You may also encounter ERR_TOO_MANY_REDIRECTS.

“I just sit at my typewriter and curse a bit.” – P.G.

Create the function (this example assumes the response_time column is responsible for the timestamp used to rotate the logs, and is in a unix timestamp format) used to rotate the logs: CREATE OR REPLACE FUNCTION "func_example_log_rotate"() RETURNS trigger…

The following error might occur after the upgrade if you have specified the db.dialect option in your local.cfg or dspace.cfg file from version 7.2 and did not make the requisite change for 7.3: Caused by: java.lang.ClassNotFoundException: Could not load…

Apt supports HTTP, HTTPS and SOCKS5H (SOCKS5 with remote DNS resolution) proxies, according to both the source code and the man page, but when specifying the proxy values on the command line, apt reports that the proxy is unsupported: root@host:~# <strong…

Having taken delivery of a brand new server with an XL710 card in it, I booted it up after setting up the DHCP reservation, and while the reservation for the dedicated BMC/IMPI interface kicked in immediately, it failed for the interfaces on the XL710 ada…

Attempting to forward a PostgreSQL port from a remote server to localhost, I saw the following error in the SSH client log: debug1: All remote forwarding requests processed debug1: Connection to port 5432 forwarding to localhost port 5432 requested. debug…

I’ve found that some tech talks and lectures are worth rewatching from time to time, usually because they’re information-dense and require a bit of research or hands-on participation from the viewers perspective to get a full understanding of the content.

I went looking for some information on the old Balistic.exe (for some reason the spelling is incorrect for the executable) game for Windows the other day, and couldn’t find any information online.

Using different databases for each application in a Django project requires multiple changes to the project: A database configuration for each database within settings.py A reference to a database router for each application, set within settings.py The da…

This guide relies on the configuration discussed in Setting up Shorewall for LXC container network bridging and routing.

To grant restricted access to a server for the purposes of forwarding a port on the user’s local machine (e.g.

Host instructions for LXC Ensure that the LXC bridge is enabled: root@host:~# cat /etc/default/lxc-net USE_LXC_BRIDGE="true" Ensure that the virtual networking kernel module is running: root@host:~# lsmod | grep veth veth 20480 0 If it is not running, l…

I had a peculiar problem where the colours on my Television looked washed out when connected to my Nvidia GTX 960.

Download wgcf and the WireGuard client (wg) and run the following: wgcf register This creates a file called wgcf-account.toml.

If you’re on Ubuntu 18.04 and higher, create a container with Ubuntu 16.04 first, and follow these instructions inside the container (this avoids issues I’ve experienced with incompatible dependencies and APIs from OpenJDK 9 and upwards).

Install the LXC package: sudo apt install -y lxc Configure LXC: mkdir ~/.config/lxc cp /etc/lxc/default.conf ~/.config/lxc cat /etc/subuid | grep "$(whoami):" | cut -f 2,3 -d : | sed 's/:/ /g' | sed 's/^/lxc.id_map = u 0 /' >> ~/.config/lxc/default.conf…

I use a set of common Linux tools for day-to-day sysadmin and computer use, and these can all be configured using dotfiles.

Thermal throttling of a CPU is visible as a reduction in clock speed under load, and is easiest to notice while monitoring both core temperature and clock speed simultaneously.

This post assumes that you have SSH access configured on the router.

Adding dark mode to a style sheet involves adding a media query to detect the user’s preference: @media (prefers-color-scheme: dark) { body { filter: invert(100); /*Functional, but lazy*/ } } It’s possible to have a global, default style sheet which is

These are the tools I use to establish a baseline of usability for the websites I develop: Pagespeed Insights Developed by Google, and open-sourced as Lighthouse, this service checks the performance of a web page, taking into account the page load time, t…

Most modern applications have followed the trend of resizing scrollbars to the point of invisibility.

Dota 2, by default, constrains the mouse cursor to the game window.