Karma Computing

How to write a secure container

How to write a secure container

So, how do you write a secure container? Rule 1: Know where your data is coming from Common things to avoid: * Pulling images from public registries * Know your dependencies Solution: Maintain your own copy of dependencies, and keep up to date when new patches are released to adress security issues

What every DevOps adoption project needs - minimum

What every DevOps adoption project needs - minimum

Context: You've asked an external company to help you work in a more DevOps like fashion. Both stakeholders want to succeed. The external company will always need the following things from you regardless of industry or project. This is the checklist: * A short explanation of all of the code repositories,

Logo minimum deliverables

The colours used Deliverable one: Document with the exact colours used E.g. The brand colours used in this logo are: Red: #FF0000 Blue: #00FF00 ...etc Deliverable two: Logo in a vector format, ideally SVG Example: Must include the logo in SVG format: logo.svg Why? Because then can be

The Evolution Of Website Builders

thinking fast and slow

The Evolution Of Website Builders

The header of this article is Lego.com from Nov 9th 1996. It gives some context for how far the web has come. It started with find & replace We literally used to have to hand write a html file for every page. There was no concept of 'templating'. Hunderds if

What is concurrent code?

What is concurrent code?

Concurrent computing - WikipediaWikimedia Foundation, Inc.Contributors to Wikimedia projects Concurrent computing is a form of computing in which several computations are executed concurrently—during overlapping time periods—instead of sequentially—with one completing before the next starts. - Wikipedia Related topics: * Dining philosophers problem

The Kubernetes history- the project which almost never happened

The Kubernetes history- the project which almost never happened

"It's 2013. The environment in silicon vally was on the heels of the devops movement, automation tools were all the rage" - Kelsey Hightower, Principal Engineer, Google. The speakers in the 2022 Kubernetes documentary by Honeypot includes a fantastic list of speakers reflecting on the early days of Kubernetes and

How to send telegram messages with python tutorial

How to send telegram messages with python tutorial

Telegram provides an amazing Bot API for developer with the need of automation. The Telegram Bot API is HTTP-based and is useful in different scenearios. In this blog, we will guide you to configure the Bot to send messages with python. For more information, you can go to the official

How to set ulimit max number open files and other limits? Help!

How to set ulimit max number open files and other limits? Help!

> You can use this reference to learn how to update any of the kernel / userspace limits. Increase max number of open files nofile ubuntu (and other os's) > Fun fact: fs.file-max is probably not what you want to change, you probably want to change ulimit. But why? The deault fs.

It's time to let go of Centos, and has been that way for a long time

It's time to let go of Centos, and has been that way for a long time

It's perhaps human nature to cling to the familiar, it's the availability heuristic (we tend to reach for solutions which are easily recalled from memory- regardless of whether it happens to be the best fit. Good enough is sometimes what you need. Case in point, a proxy 'envoy proxy', is

How to disable Wordpress https redirect, the many ways

How to disable Wordpress https redirect, the many ways

For local dev this is useful. Because Wordpress is a wild west there may be different reasons your wordpress install is redirecting to https when you don't want it to: #1 Update wp-config.php Inside your `wp-config.php`: define('WP_HOME','http://example.co.uk'); #2 Check .htaccess There might

TiDB SQL Database NewSQL

TiDB SQL Database NewSQL

Little known in the UK TiDB (soon to launch TiDB Cloud) is a significant change in how you think about traditional relational database- which typically can't scale horizontally. > TiDB: Distributed, horizontally scalable, MySQL compatible - Morgan Tocker , TiDB talk at FOSDEM TiDB promises (and delivers) on both these goals: A

Better payment systems around the world

Better payment systems around the world

Without fees. Unified Payments Interface - WikipediaWikimedia Foundation, Inc.Contributors to Wikimedia projects It exists in India via UPI I think. https://en.wikipedia.org/wiki/Unified_Payments_Interface s It's proving extremely successful so far, and has been viewed as one of the best financial inventions over there. src

Building a SaaS based architecture on a budget without vendor lock-in

Building a SaaS based architecture on a budget without vendor lock-in

Opinionated account on a micro SaaS currently processing ~53k api requests daily and ~£3k monthly. Actual code, real lessons learnt the hard way. I wrote about SaaS based architectures earlier in 2020 which goes into detail on the tradeoffs around multi tenancy. We reject: kings, presidents and voting.We believe

A brief look at OpenAFS

A brief look at OpenAFS

I have a keen interest in opensource history and trying to understand which technologies hyperscalers may be using, or at least the technologies which came before them- the influences. With EFS (Another Web Service), I couldn't help but feel maybe there maybe similarities with other open file systems and was

It's not about scalability it's about developer experience which makes experimentation fast

thinking fast and slow

It's not about scalability it's about developer experience which makes experimentation fast

In his interview, The untold story of SQLite [https://corecursive.com/066-sqlite-with-richard-hipp/#], author D. Richard Hipp explains beautifully the value in fast experimentation - this is a real world practical example from history of how leaders in an industry get eaten for breakfast, whilst they don't even realise it's happening.

How to create your own pip package example python

How to create your own pip package example python

Example code repo for post [https://github.com/KarmaComputing/create-your-own-python-pip-package] Being able to package your python project into a pip package is useful for distribution, and sharing with others especially if the code is generic enough to be useful in other projects). This repo is base on the tutorial: from

Docker tail -f from the end

Docker tail -f from the end

The docker way: docker logs -f --tail 10 container_name The host way $(docker inspect --format='{{.LogPath}}' # Then tail -f the file Ref * https://stackoverflow.com/questions/42510002/docker-how-to-clear-the-logs-properly-for-a-docker-container * https://stackoverflow.com/questions/52119832/how-to-tail-a-docker-log-from-the-current-position-in-the-log-without-seeing-the

Rust create ubuntu / debian package from cargo

Rust create ubuntu / debian package from cargo

Rust how to create a deb package with cargo deb

How to get started with rust

How to get started with rust

How to I install rust? See https://www.rust-lang.org/tools/install Or run: curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh How do I compile a rust program? Use rustc E.g. rustc main.rs The output is a binary main. Where does rust/cargo

Shrink existing partition mdraid linux ext4 using resize2fs

Shrink existing partition mdraid linux ext4 using resize2fs

How do I know what filesystem type it is? df -T How do I view the current disk(s) layout? lsblk -f 1. unmount the drive's partition you want to shrink umount /dev/md3 If you see umount: : target is busy. then you may need to cd out of the

What is an unhandled exception mean?

What is an unhandled exception mean?

Generally an unhandled exception in your code means that your program is in a condition or state that you have not described to the computer how to handle that situation. What does "node --unhandled-rejections=strict" mean? E.g. node --unhandled-rejections=strict main.js Sure good question! Focus on the word

Playwright tutorial example configuration

Playwright tutorial example configuration

Playwright provides a fast and reliable interface that can be used to automate browser navigation testing. In this Playwirght tutorial, we are going to use it to do some simple automated test and errors you might experience in the process. See the following Github repository: GitHub - KarmaComputing/playwright-testingContribute to

Debug python containers pdb docker breakpoint

Debug python containers pdb docker breakpoint

Debugging python docker containers with remote-pdb, docker-compose You want to debug and set breakpoints inside your docker container and/or you want to debug with docker-compose. > Warning: As the docs say: The debug host in your Docker container must be set to 0.0.0.0 (localhost or 127.0.

How to check if logrotate is working

How to check if logrotate is working

Check that the logrotate is working as expected See man logrotate for all the options, check it's running correctly by using verbose mode and reading the output: logrotate -v /etc/logrotate.d/ Is your log file growing faster than the daily/weekly interval? Use the maxsize option and check how

Does git rm delete the file?

Does git rm delete the file?

tldr; Yes. Yes it does. (use git restore --staged to un-delete if you made that mistake*) Does git rm remove the file? How to find out yourself: See man git rm or read on. Sometimes you find git is tracking files (e.g. binary files like images) which you shouldn't