kgrz

Virtual Networking on Linux

In the Linux Kernel, support for networking hardware and the methods to interact with these devices is standardized by the socket API:

                +----------------+
                |   Socket API   |
                +-------+--------+
                        |
User space              |

kgrz

Disclaimer: I'm not the original author of this sheet, but can't recall where I found it. If you know the author, please let me know so I give the attribution.

Note: Since this seems to be helpful to some people, I formatted it to improve readability of the original. Also, note that this is from 2016, many things may have changed, and I don't use macOS anymore, so I probably can't help in case of questions, but maybe someone else can.

Mac Network Commands Cheat Sheet

After writing up the presentation for MacSysAdmin in Sweden, I decided to go ahead and throw these into a quick cheat sheet for anyone who’d like to have them all in one place. Good luck out there, and stay salty.

Get an ip address for en0:

kgrz

The Wisdom of Quinn

Informative DevForum posts from everyone's favorite DTS member.

(Arranged newest to oldest)

• The Peril of the Ampersand
• Signing code for older versions of macOS on Apple Silicon
• Local Network Privacy FAQ
• Triggering the Local Network Privacy Alert
• Standard Memory Debugging Tools
• Using the Multicast Special Entitlement

kgrz

# to generate your dhparam.pem file, run in the terminal
openssl dhparam -out /etc/nginx/ssl/dhparam.pem 2048

kgrz

vimgrep

• Vimcasts on vimgrep

• Uses native vim regexes (which are slightly different from the regexes used by grep, ack, ag, etc) so the patterns are the same as with vim's within-file search patterns.

You can do a normal within-file search first, then re-use the same pattern to

kgrz

(I'm enjoying doing these raw, barely edited writeups; I hope they're useful to you too)

Feature flags

This is my own writeup on feature flags; for a deep dive I'd recommend something like Martin Fowler's article (https://martinfowler.com/articles/feature-toggles.html).

So. Feature flags. The basic idea that you'll store configuration/values on a database/service somewhere, and by changing those values, you can change the user experience/features for a user on the fly.

Let's say that you're building a new feature, called 'new-button' which changes the color of buttons, which is currently red, to blue. Then you'd change code that looks like this -

kgrz

tell application "System Preferences"
	activate
end tell

tell application "System Events"
	tell process "System Preferences"
		activate
		delay 1
		click menu item "Displays" of menu "View" of menu bar 1
		delay 1

kgrz

Mistakes to Avoid: Docker Antipatterns

Whichever route you take to implementing containers, you’ll want to steer clear of common pitfalls that can undermine the efficiency of your Docker stack.

Don’t run too many processes inside a single container

The beauty of containers—and an advantage of containers over virtual machines—is that it is easy to make multiple containers interact with one another in order to compose a complete application. There is no need to run a full application inside a single container. Instead, break your application down as much as possible into discrete services, and distribute services across multiple containers. This maximizes flexibility and reliability.

Don’t install operating systems inside Docker containers

It is possible to install a complete Linux operating system inside a container. In most cases, however, this is not necessary. If your goal is to host just a single application or part of an application in the container, you need to install only the essential

kgrz

Removal of McAfee from OSX

Note: This was written in 2015, it may be out of date now.

There are a lot of commands here which I use sudo if you don't know what you're doing with sudo, especially where I rm you can severely screw up your system.

There are many reasons which you would want to remove a piece of software such as McAfee, such as not wanting it to hammer your CPU during work hours which seems like primetime for a virus scan.

I intend this to be a living document, I have included suggestions from peoples' replies.

kgrz

A collection of The Morning Paper posts relating to containers, operating systems etc.

In order of first appearance in The Morning Paper.

• On the duality of operating system structures
• Why threads are a bad idea
• Why events are a bad idea
• Unikernels: library operating systems for the cloud
• The scalable commutativity rule: designing scalable software for multicore processors
• Jitsu: just-in time summoning of unikernels