# Tech notes [Markdown Syntax](https://www.markdownguide.org/basic-syntax/) ```Python print('This is a test') ``` [Alarm](https://telsak.se/alarm.mp3) ## Webstuff ### PHP ADFS SSO - Booking system running on PHP using ADFS authentication for secure logins. [AD in applications for SSO](https://medium.com/@prasoon_98674/how-to-integrate-active-directory-in-php-application-for-sso-22eb62b6b866) SimpleSAML.php is an award-winning application written in native PHP that deals with authentication. The project is lead by UNINETT, has a large user base, a helpful user community and a large set of external contributors. [https://simplesamlphp.org](https://simplesamlphp.org) <br> ## Linux ### Active/Passive failover (VRRP) - [Keepalived](https://github.com/acassen/keepalived) Keepalived implements a set of checkers to dynamically and adaptively maintain and manage loadbalanced server pool according their health. On the other hand high-availability is achieved by the Virtual Router Redundancy Protocol (VRRP). - Resources: Video on [Active-Passive Cluster with Keepalived & HAProxy](https://www.youtube.com/watch?v=NizRDkTvxZo) (Mar 20, 2020) Docker GitHub for [osixia/docker-keepalived](https://github.com/osixia/docker-keepalived) <br> - [HAProxy](http://www.haproxy.org/) HAProxy is a free, very fast and reliable solution offering high availability, load balancing, and proxying for TCP and HTTP-based applications. It is particularly suited for very high traffic web sites and powers quite a number of the world's most visited ones. Over the years it has become the de-facto standard opensource load balancer, is now shipped with most mainstream Linux distributions, and is often deployed by default in cloud platforms. - Resources: Video on [HAProxy Crash Course (TLS 1.3, HTTPS, HTTP/2 and more)](https://www.youtube.com/watch?v=qYnA2DFEELw) (Dec 27, 2019) <br> - MySQL __sorry :(__ `mysql_connect()` function doesn't exist in PHP7.0. Migrate to [PDO](https://www.php.net/manual/en/ref.pdo-mysql.php) instead. ## Windows ### 10 - Build in terminal packet sniffer [pktmon](https://isc.sans.edu/forums/diary/Windows+10+Builtin+Packet+Sniffer+PktMon/26186/) Microsoft released with the October 2018 Update a built-in packet sniffer for Windows 10 located in C:\Windows\system32\PktMon.exe. In order to collect packets you need to launch a Windows 10 command prompt as admin before using PktMon.