Category Archives: Uncategorized

Workout sketches for fun!

I won’t add much text here, as these are mostly for my own reference and describing each would take quite some time, while hopefully images are explanatory enough.

I’d just say these exercises were collected from the additional materials for the “Training For The New Alpinism” book, some other training materials and personal experiments.

Radial Charts


I wanted to plot the data that is tightly connected to a time of a day as a circular chart, resembling the clock face – for no particular reason other than checking out how it looks.

Another thing I wanted to do was to play with some relatively modern JS framework.

And then I also got a bit a of a spare time on my hands.


So as a result, here’s a code that fetches CSV data from Graphite metrics (or any other CSV file) and displays it on a radial chart (aka Radar chart). It’s crude and unoptimised and inefficient, but it serves the goal of visual representation (see examples section below):

It’s mostly an amCharts showcase – amCharts are amazing, I love them dearly. Check them out if you’re not familiar, there’s seemingly nothing you can’t do with them:

Additionally, it also uses Github Actions ( as a CI mechanism – so on every push a build is pushed to a branch and then deployed as Github pages using (there’s many action plugins, this one was just the first one that worked).


Surprisingly, there’s npt that many public datasets with high-granularity daily data available on the Internet, but here’s at least one:
Bike rentals in NYC, January 1st 2020 vs July 1st 2019 (from

Bike rentals


  • it’s not a working tool or a developing project – it’s a fun thing built for no reason
  • it loads a ton of unnecessary libraries, becasue how amCharts library for Vue.js is structured, and also because it’s not optimised for anything
  • <many other things>

Mandelbrot set

I was always fascinated by the Mandelbrot set pictures and always wanted to create a representation myself, but never really got to do it – till a few days ago when I stumbled over an article boiling the code down to a very simple sequence ( – so I just took it and made parameters adjustable. Also used it as an exercise in Vue.js, as it was another thing I wanted to try but never did.

It’s a very-very crude solution, but it was a good exercise:

Also the code is here (well, it’s also in the html file, but FTR):

Permanently adding SSH private key to OSX keychain

It’s been bugging me for quite a while, but never enough to go and find a solution – until now.

Shamelessly re-posting a perfect guidance from

On OSX, the native ssh-add client has a special argument to save the private key’s passphrase in the OSX keychain, which means that your normal login will unlock it for use with ssh. On OSX Sierra and later, you also need to configure SSH to always use the keychain (see Step 2 below).

Alternatively you can use a key without a passphrase, but if you prefer the security that’s certainly acceptable with this workflow.

Step 1 – Store the key in the keychain

Just do this once:

ssh-add -K ~/.ssh/[your-private-key]

Enter your key passphrase, and you won’t be asked for it again.

(If you’re on a pre-Sierra version of OSX, you’re done, Step 2 is not required.)

Step 2 – Configure SSH to always use the keychain

It seems that OSX Sierra removed the convenient behavior of persisting your keys between logins, and the update to ssh no longer uses the keychain by default. Because of this, you will get prompted to enter the passphrase for a key after you upgrade, and again after each restart.

The solution is fairly simple, and is outlined in this github thread comment. Here’s how you set it up:

  1. Ensure you’ve completed Step 1 above to store the key in the keychain.
  2. If you haven’t already, create an ~/.ssh/config file. In other words, in the .ssh directory in your home dir, make a file called config.
  3. In that .ssh/config file, add the following lines:Host * UseKeychain yes AddKeysToAgent yes IdentityFile ~/.ssh/id_rsa Change ~/.ssh/id_rsa to the actual filename of your private key. If you have other private keys in your ~.ssh directory, also add an IdentityFile line for each of them. For example, I have one additional line that reads IdentityFile ~/.ssh/id_ed25519 for a 2nd private key.The UseKeychain yes is the key part, which tells SSH to look in your OSX keychain for the key passphrase.
  4. That’s it! Next time you load any ssh connection, it will try the private keys you’ve specified, and it will look for their passphrase in the OSX keychain. No passphrase typing required.

Hello horde!

I’m gonna reflect the Info page content here – because it’s, well, the same.

This is all about tech. It’s hard to describe, really – because things I’m planning to post here, they’re not connected to any particular subject, scope or kind of tech world. It could be MySQL table structure hint, followed by new action camera review and then notes about flight aboard that trendy Dreamliner. Or a videogame review. Or even something as abstract as “if I were a giant robot in a shape of a cow” thoughts. But it’s all tech, you see.

“Why do we need another tech blog?”, you might ask. And my answer would be “For no reason, you certainly do not”. But I do. This is a storage, really – different stuff that doesn’t fit Evernote, that exceeds simple occasional note form, begs for publicity, threatens to get lost and wither forever otherwise.

So to summarize and emphasize: I’m a geek and a nerd, planning to push the entropy a tad bit more uphill by littering digital world with mostly useless (to the world) but (sometimes) precious (to me) bits and pieces, shaped in words.

Fin. (not related to a fish)