Kevin M. Gallagher ageis

zcash-monitor.py

This is a script written in Python intended to run alongside a Zcash node and export statistics for monitoring purposes. It assumes the existence of zcash-cli in the PATH and access to the RPC interface over localhost.

It tracks stuff like: block height, difficulty, number of peers, network solutions per second, errors, mempool size, size of recent blocks, number of transactions within blocks, chaintips, total bytes received and sent, transaction inputs and outputs, and the make-up of transactions in terms of JoinSplits, shielded, unshielded or mixed. These Zcash metrics are refreshed once every 2 minutes.

How it works

Prometheus is a monitoring system and time-series database.

bitcoind-monitor.py

This is a script written in Python intended to run alongside a Bitcoin node and export statistics for monitoring purposes. It assumes the existence of bitcoin-cli in the PATH and access to the RPC interface over localhost.

It tracks stuff like: block height, difficulty, number of peers, network hash rate, errors, uptime in seconds, mempool size, size of recent blocks, number of transactions within blocks, chaintips, total bytes received and sent, and transaction inputs and outputs. These Bitcoin metrics are refreshed once every 5 minutes.

How it works

Prometheus is a monitoring system and time-series database.

YubiKey 4 series GPG and SSH setup guide

Written for fairly adept technical users, preferably of Debian GNU/Linux, not for absolute beginners.

You'll probably be working with a single smartcard, so you'll want only one primary key (1. Sign & Certify) and two associated subkeys (2. Encrypt, 3. Authenticate). I've published a Bash function which automates this slightly special key generation process.

security and hardening options for systemd service units

A common and reliable pattern in service unit files is thus:

NoNewPrivileges=yes
PrivateTmp=yes
PrivateDevices=yes
DevicePolicy=closed
ProtectSystem=strict

	#!/bin/bash
	# Installs as many fonts for Figlet/Toilet as possible from multiple sources.
	# Author: Kevin M. Gallagher (@ageis)

	#set -u
	#set -x
	export FIGLET_FONT_DIR=$(figlet -I2)
	export TMP_FONT_DIR="$(pwd)/fonts"
	export TMP_DEST_DIR="$(pwd)/tmp"
	export FONT_REGEX=".*\.\(flf\\|tlf\\|flc\)$"

	#!/usr/bin/python
	# -- coding: utf-8 --
	""" Simple Prometheus exporter for traffic metrics
	from a running Tor daemon. """
	import re
	import time
	import sys
	from prometheus_client import start_http_server, Gauge
	import stem
	from stem.control import Controller

	function updateall() {
	#set -o pipefail noclobber erexit
	set -v
	#set -e
	#set -x
	function exit_error() {
	echo "You can only run updateall() once at a time." >&2
	}
	function status() {
	echo "Exit code is $1"

	#!/bin/bash
	# Measures ICMP and DNS latency to many popular public DNS servers.
	# Works concurrently or in parallel.
	# Author: Kevin M. Gallagher (@ageis)
	#set -x
	#set -e
	#set -o nounset
	#set -v

	export ERRFILE="./testdns_errs.txt"

	#!/bin/bash

	function stop () {
	sudo systemctl stop "$1"
	sleep 3s
	}

	function start () {
	sleep 3s
	sudo systemctl start "$1"

	/hex
	scd serialno
	scd apdu 00 20 00 81 08 40 40 40 40 40 40 40 40
	scd apdu 00 20 00 81 08 40 40 40 40 40 40 40 40
	scd apdu 00 20 00 81 08 40 40 40 40 40 40 40 40
	scd apdu 00 20 00 81 08 40 40 40 40 40 40 40 40
	scd apdu 00 20 00 83 08 40 40 40 40 40 40 40 40
	scd apdu 00 20 00 83 08 40 40 40 40 40 40 40 40
	scd apdu 00 20 00 83 08 40 40 40 40 40 40 40 40
	scd apdu 00 20 00 83 08 40 40 40 40 40 40 40 40