Ivan Shvedunov ivan4th

The purpose of this document is to get you familiar with the concepts and command line tools involved with connecting to the internet using modern 4G LTE modems on both Debian/Ubuntu and OpenWRT.

This writeup is based on my experiences with the Sierra Wireless AirPrime MC7455 modem and a Calyx (Sprint) SIM card, but it should apply to most modern 4G LTE modems.

High level overview

These are the steps required:

Physically connect antennas

Nginx TLS SNI routing, based on subdomain pattern

Nginx can be configured to route to a backend, based on the server's domain name, which is included in the SSL/TLS handshake (Server Name Indication, SNI).
This works for http upstream servers, but also for other protocols, that can be secured with TLS.

prerequisites

at least nginx 1.15.9 to use variables in ssl_certificate and ssl_certificate_key.
check nginx -V for the following:
```
...
TLS SNI support enabled
```

If you have a Linux machine with KVM on it, you can manage those VMs remotely from a Mac using virt-manager.

Step 1: Allow your user non-root access to KVM

SSH to the Linux machine and add your SSH user to the libvirt group

sudo usermod -a -G libvirt $(whoami)

Using Multus CNI in K3S

By default, K3S will run with flannel as the CNI and use custom directories to store CNI plugin binaries and config files(You can inspect the kubelet args K3S uses via journalctl -u k3s|grep cni-conf-dir). So you need to configure that properly When deploying Multus CNI.

For example given the official Multus manifests in https://github.com/intel/multus-cni/blob/36f2fd64e0965e639a0f1d17ab754f0130951aba/images/multus-daemonset.yml, the following changes are needed:

volumes:
 - name: cni

`$HOME`, Not So Sweet `$HOME`

Preface
1 What is $HOME to you?
2 Setup
- 2.1 Linux
2.1.4 xdg-user-dirs

	#!/usr/bin/env bash
	{ set +x; } 2>/dev/null

	IFS=$'\n'
	set "$@" $(find ~ -name ".*" ! -name ".CFUserTextEncoding" ! -type l -mindepth 1 -maxdepth 1) # dotfiles
	set "$@" $(find ~ -name "Google *" -mindepth 1 -maxdepth 1) # Google Drive
	set "$@" ~/git # store on github/etc :)
	set "$@" ~/node_modules

	set "$@" ~/Applications # install apps with brew cask