Sam Mingo slmingol

Routing tips for VPNs on OS X

When VPNs Just Work™, they're a fantastic way of allowing access to a private network from remote locations. When they don't work it can be an experience in frustration. I've had situations where I can connect to a VPN from my Mac, but various networking situations cause routing conflicts. Here are a couple of cases and how I've been able to get around them.

Specific cases

Case 1: conflicting additional routes.

In this example the VPN we are connecting to has a subnet that does not conflict with our local IP, but has additional routes that conflict in some way with our local network's routing. In my example the remote subnet is 10.0.x.0/24, my local subnet is 10.0.y.0/24, and the conflicting route is 10.0.0.0/8. Without the later route, I can't access all hosts on the VPN without manually adding the route after connecting to the VPN:

Getting the Gist of GitHub Actions

Tutorial and tips for GitHub Actions workflows

Terminal Colors

There exists common confusion about terminal colors. This is what we have right now:

Plain ASCII
ANSI escape codes: 16 color codes with bold/italic and background
256 color palette: 216 colors + 16 ANSI + 24 gray (colors are 24-bit)
24-bit true color: "888" colors (aka 16 milion)

Command Line Crash Course

Cheatsheets

Overview: running crc on a remote server

This document shows how to deploy an OpenShift instance on a server using CodeReady Containers (crc) that can be accessed remotely from one or more client machines (sometimes called a "headless" instance). This provides a low-cost test and development platform that can be shared by developers. Deploying this way also allows a user to create an instance that uses more cpu and memory resources than may be available on his or her laptop.

While there are benefits to this type of deployment, please note that the primary use case for crc is to deploy a local OpenShift instance on a workstation or laptop and access it directly from the same machine. The headless setup is configured completely outside of crc itself, and supporting a headless setup is beyond the mission of the crc development team. Please do not ask for changes to crc to support this type of deployment, it will only cost the team time as they politely decline :)

The instructions here were tested with F

	#!/usr/bin/env bash
	## Copyright (C) 2017, Oleksandr Kucherenko
	## Last revisit: 2017-09-29

	# For help:
	# ./versionip.sh --help

	# For developer / references:
	# https://ryanstutorials.net/bash-scripting-tutorial/bash-functions.php
	# http://tldp.org/LDP/abs/html/comparison-ops.html

	#!/bin/bash -x

	workdir="${HOME}/workdir"
	[[ ! -d "$workdir" ]] && ( mkdir -p "$workdir" \|\| exit 1)
	[[ ! -d "$workdir"/tmp ]] && ( mkdir -p "$workdir"/tmp \|\| exit 1)
	[[ ! -d "$workdir"/output ]] && ( mkdir -p "$workdir"/output \|\| exit 1)
	echo "workdir is ${workdir}"
	tmpdir=$(mktemp -d deb_XXXX -p "$workdir"/tmp)
	deb_temp=${tmpdir}/deb
	extract_tmp=${tmpdir}/extract

	#!/bin/bash
	# Plays a random MOD file from https://modarchive.org
	# Depends on XMP (http://xmp.sourceforge.net/)

	rand=$(shuf -i 1-189573 -n 1)
	tmp=$(mktemp /tmp/${rand}.XXXXXXXX.mod)
	curl https://modarchive.org/jsplayer.php?moduleid=${rand} > ${tmp}
	xmp ${tmp}
	rm ${tmp}