tmcolby

from flask import Flask, abort, request
from werkzeug.utils import secure_filename
import os
import requests
import json

# change this to set where you want the file to be saved
UPLOAD_FOLDER = "./"

# change this to only allow files with a given extension to be accepted

tmcolby

git reset --hard HEAD
git clean -f -d
git checkout master
git fetch origin master
git reset --hard origin/master
git pull
git submodule update
git submodule update --init --recursive
git submodule foreach git reset --hard HEAD
git submodule foreach git clean -f -d

tmcolby

Use-case:
I have two servers running on my host instance.
The first, step-ca running on local port 1442.
The second, an ACL server running on local port 2443.
Each server terminates TLS directly.

I want both servers accessable from the public internet on port 443.
In this case, I have two DNS A records pointing to the same public IP address of the host instance.

I want requests to the CA @ https://ca.mydomain.io to be passed through to localhost:1443.

tmcolby

https://www.freedesktop.org/software/systemd/man/systemd-nspawn.html
chroot improved.

on arch - i needed qemu-user-static AUR. it takes FOREVER to biuld.
the conf files were absent and so systemd-binfmt (instead of binfmt-support) was failing to load. followed this and resolved: https://github.com/computermouth/qemu-static-conf/blob/master/README.md

create loopback of the raspberrypi.img file
sudo losetup -P -f --show some/path/to/raspbian.img
assuming loop0, mount the boot and rootfs
sudo mkdir-P /mnt/rpi

tmcolby

https://raspberrypi.stackexchange.com/questions/36456/how-to-shrink-an-image-file-after-allocating-full-space
http://www.knight-of-pi.org/how-to-shrink-raspberry-pi-sd-card-images-with-gparted-and-dd/

tmcolby

default-lease-time 86400;  
max-lease-time 86400;

authoritative;

log-facility local7;

subnet 172.17.1.0 netmask 255.255.255.0{
  range 172.17.1.100 172.17.1.200;

tmcolby

sudo apt-get install python3-dev libffi-dev libssl-dev -y
wget https://www.python.org/ftp/python/3.6.3/Python-3.6.3.tar.xz
tar xJf Python-3.6.3.tar.xz
cd Python-3.6.3
./configure
make
sudo make install
sudo pip3 install --upgrade pip

tmcolby

Elevate to root privilage, in VIM, on the go

Suppose you opened a file in the Vim editor, made a lot of changes, and then when you tried saving those changes, you got an error that made you realize that it's a root-owned file, meaning you need to have sudo privileges to save these changes.

:w !sudo tee %

The aforementioned command will ask you for root password, and then let you save the changes.

Credit: https://www.howtoforge.com/linux-tee-command/

tmcolby

# predictable enumeration based on physical port the usb serial adapter is plugged into
# Hardware	: BCM2835       raspberry pi 3b
# Revision	: a02082

# view looking at the ports of the pi
# usbSerial0  usbSerial1
# usbSerial2  usbSerial3
KERNELS=="1-1.2", SUBSYSTEMS=="usb", SUBSYSTEM=="tty", ATTRS{devpath}=="1.2", SYMLINK+="usbSerial0", GROUP="dialout", MODE="0666"
KERNELS=="1-1.3", SUBSYSTEMS=="usb", SUBSYSTEM=="tty", ATTRS{devpath}=="1.3", SYMLINK+="usbSerial2", GROUP="dialout", MODE="0666"
KERNELS=="1-1.4", SUBSYSTEMS=="usb", SUBSYSTEM=="tty", ATTRS{devpath}=="1.4", SYMLINK+="usbSerial1", GROUP="dialout", MODE="0666"

tmcolby

This first example assumes two usb serial port adapters are connected to the host machine.  They enumerate as ttyUSB0 and ttyUSB1.
We want data coming into ttyUSB0 to be piped right back out of ttyUSB1 (so our host sits as a man in the middle).
We want an application running on the host to be able to connect to a com port and monitor the traffic.

# create the fifo
sudo mkfifo -m 777 /tmp/fifo

# stream serial data on /dev/ttyUSB0 to the fifo AND a virtual com port /tmp/relay
sudo socat /dev/ttyUSB0,raw,echo=0 system:'sudo tee /tmp/fifo | sudo socat - "pty,raw,echo=0,link=/tmp/relay"' &