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FlorianHeigl / cheatsheets.md
Last active May 13, 2021
Printable Cheat Sheets for Software
View cheatsheets.md

A collection of links to useful cheat sheets.

Only what's properly printable can get a spot at the top of this list. It should also be small enough to fit on a few pages. almost all links in this document were designed by their creators so that YOU can print them in a good-looking format and store them however is best for you. Anything that isn't really something you could print in A4/US Letter format, but is still a well-made cheatsheet can get a spot at the end of the page.

Pleae contribute any you remember you've seen and liked. It would be wonderful if we can get these to be something more commonly made.

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@FlorianHeigl
FlorianHeigl / testing layers
Last active Jun 29, 2017
Testing reqs in Ops envs on top of "normal" tests
View testing layers
--------------------------------------
||| Test return to stable state
--------------------------------------
||| External Fault injection tests
--------------------------------------
||| System health
--------------------------------------
\========/
Below: \ /
"insufficient tests for OS code
@FlorianHeigl
FlorianHeigl / zypper_bench.md
Last active Jul 9, 2017
Performance of zypper tested (deltaRPM, prefetching)
View zypper_bench.md

The test

Install a mixed update for Leap42.1 consisted of 106 packages including kernel update and a very slow samba update script
Try prefetching the updates (i.e. an hour before the downtime)
Try disabling deltaRPM

Caches NOT dropped, all packages likely to stay in cache on today's servers.

VM size:

@FlorianHeigl
FlorianHeigl / ssh.md
Created Aug 13, 2017 — forked from spuder/ssh.md
logstash-grok-ssh ignore root user
View ssh.md

I have ssh connections from multiple users. I want to log all connectsion except those from the user 'git'. How dow you create an exception to a filter ?

input {

  file {
     path => "/var/log/auth.log"
     type => "syslog"
  }
}
@FlorianHeigl
FlorianHeigl / bacula-fd.conf
Created Sep 11, 2017
bacula config mixing letsencrypt and cacert
View bacula-fd.conf
## server: cacert
## client: letsencrypt
TLS Enable = yes
TLS Require = yes
TLS CA Certificate File = /etc/letsencrypt.sh/certs/host.domain.tld/chain.pem
TLS Certificate = /etc/letsencrypt.sh/certs/host.domain.tld/cert.pem
TLS Key = /etc/letsencrypt.sh/certs/host.domain.tld/privkey.pem
TLS CA Certificate Dir = /etc/ssl/certs
@FlorianHeigl
FlorianHeigl / swmaintainability.md
Last active Feb 4, 2020
Common architecture issues make patching "HARD"
View swmaintainability.md

Common architecture issues make patching "HARD"

An attempt to explain where exactly we can improve things.
From someone with hope, but without even the smallest grain of illusion.

I could just say "well, it was US who carried VMS to it's grave!"
It wouldn't help much. We're definitely looking at long-solved problems that aren't solved any longer due to design limitations in our OS and application integrations. The question is how to get around it.

@FlorianHeigl
FlorianHeigl / human-reliability-and-friends.md
Last active Nov 26, 2017
human reliability and friends
View human-reliability-and-friends.md

Presentation Title

50 years of reliability engineering

Abstract

Large-scale systems like power grids, chemical processing, nuclear power,
traffic control or air and space travel have been around for quite some time.
Most of these are still larger than what we manage, but we are catching up.
Modern deployment methods and better schedulers allow for more scalability,

View lala
put the valves on ground floor
in shielded rooms
@FlorianHeigl
FlorianHeigl / open-valves.md
Last active Jan 30, 2018
containment venting during blackout
View open-valves.md
  • put the valves on ground floor
  • make a shielded compartment around the valves
  • some chance of survival, valves can be openend