ansible playbook increasing log log retention period
i needed to adjust local log retention period on bunch of servers. rules: with some help from chatgpt and grog3 i’ve cobbled this one:
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rsync without retransmitting moved files
i’m using rsync a lot; both at work [ backups, replication of content to various servers, ad-hoc copying ] and privately. it’s smart enough to avoid re-sending the whole file if it has grown a bit [ like logs like to do ] or only few bytes changed in source or destination. out-of-the-box rsync is ... Read More
Ideas: rsync-like tool parallelizing transfer of large files
i use rsync heavily for backups, batch jobs and one-off tasks. every day it moves around terabytes of data for me. while it’s great – saves time and bandwidth, it could make even better use of modern hardware – multicore, and often with plenty of unused storage IOps: one day, when i’ll have some spare ... Read More
splitting ebook in one mp3 into multiple files
my daughter likes to listen to audiobooks; some of them come from youtube, some are multi-hour long. it’s easier to listen, re-listen if book is chopped into shorter chapter-alike files. how do i do it? yt-dlp is a swiss army knife for downloading audio/video from multiple hosting services mp3splt allows to split mp3 files in ... Read More
Hong Kong, again
i got yet another chance to travel to Hong Kong. i’ve spent there 9 days in October this year. what did change since my previous visit in 2018? what did not change: few places that i’ve hiked around for the first time: Lamma Island – i got there with a ferry from Central. concrete path ... Read More
beko dishwasher showing e01 code
our dishwasher stopped working, displayed E01 code and whenever closed was running drain pump all the time. i’ve called their support and learned it’s a known anti-flood feature and is caused by water that leaked gradually out of dishwasher and stayed in its base. solution? makes you wonder why does the water leak out of ... Read More
Using mitmproxy to allow closed-source application to communicate with licensing server with expired TLS cert
we’re using a 3rd party library that shall remain nameless. vendor provides this library to us in form of few .so files, few headers and sample code. we have a small custom c++ wrapper for it. whenever library is initialized – it makes a call to licensing server and does some challenge/response verification. on one ... Read More
Sound-generating online apps
list of few online apps that my daughter likes: longer lists of tools:
random things that inspire me
SQLite’s code of ethics: https://www.sqlite.org/codeofethics.html altamira’s ten investment commandments
New supermicro server does not ‘see’ some of NVMe drives
i got 3 identical new servers from supermicro – SYS-121C-TN10R. all three have the same disk setup – 2+4 NVMe drives, but Debian 12 just see 5 of them instead of 6. when i run dmesg on newly installed system i can see those errors: to solve it i had to change PCIe bifurcation in ... Read More
charging Amazfit Band 5
i’m a happy user of Amazfit Band 5. it’s dirt cheap, paired with gadgetbridge – works fine without sharing any data with cloud-hosted big brother, all in all – it helps to keep me moving around each day. i had few occasions when i needed to charge it [ every ~2 weeks ] and did ... Read More
cheescake recipe
ingredients: procedure:
Fastly returning “Requested host does not match any Subject Alternative Names (SANs) on TLS certificate”, HTTP/421
due to $reasons we have an nginx-proxy that is a reverse proxy forwarding to Fastly CDN which, in turn, forwards back to our infrastructure. starting from the 2024-02-27 this stopped working, for some HTTP queries. most notably those using OPTION verb. response that nginx was getting from Fastly had HTTP/421 status code and payload: colleague ... Read More
KVM – listing VMs with their memory allocation
i needed to list all VMs on given KVM server and sort them by amount of RAM allocated to each. ugly but does the trick.
Ohook – activating MS office
this might be useful, especially for environments where automated tests of MS-office-dependent applications are done: https://massgrave.dev/ohook.html + https://github.com/asdcorp/ohook
podcast about evolution of mysql at booking.com
very interesting, content-heavy, interview with Kristian Köhntopp about his work at booking.com: 1, 2 [ alternatively on youtube: 1, 2 ].
getting code signing certificate on own Yubikey and then using it to sign windows binaries in unattended way, on KVM VM
starting from June 2023 code signing certificates for MS Windows cannot be delivered as a file anymore. files are easy to steal. now certs must reside on security modules which don’t allow private key extraction, at least not for mere mortals. we’re using such a cert to sign exe and msi files on a build ... Read More
freecad – editing STL file
for 0.21.2 based on this yt video: https://www.youtube.com/watch?v=dr1qtaURrvI
parallel rsync
rsync remains my main tool for transferring backups or just moving data between servers. but it has some pain points – e.g. rsync’s checksum calculation or ssh over which data is piped can easily saturate single CPU core before i run out of storage I/O or network bandwidth. how to parallelize it – based on ... Read More
resources for learning SQL
SQL basics: indexes: https://use-the-index-luke.com/ ‘modern’ SQL: fiddles – web-based sandboxes: