Michael Diamond dimo414

Build the Luit/dogebot binary (I prefer to do so in a Docker container) for ARM:

$ docker run -v /tmp:/mnt/tmp -it debian:testing
docker$ apt-get update && apt-get install -y git golang
# Ensure build dependencies are available locally
docker$ go get github.com/Luit/dogebot/src/dogebot
docker$ git clone https://github.com/Luit/dogebot
docker$ cd dogebot/src/dogebot
# Build a Raspberry Pi binary

Expanding Bash arrays safely with `set -u`

Prior to Bash 4.4 set -u treated empty arrays as "unset", and terminates the process. There are a number of possible workarounds using array parameter expansion, however almost all of them fail in certain Bash versions.

This gist is a supplement to this StackOverflow post.

This article includes setup instructions for the Raspberry Pi camera, but doesn't capture setting it up as a service (even though a few lines up it sets up OctoPrint as a service), and instead provides a pair of relatively-complex scripts to be run at startup via /etc/rc.local.

Setup

copy webcam.sh to the mjpg-streamer directory (or wherever you'd like, just update the MJPG_DIR variable)
copy pi-webcam.service to /etc/systemd/system/ (requires sudo), ensure ExecStart points to the correct path

	#!/bin/bash
	# Source: https://gist.github.com/dimo414/10d6f162fb6d72f517a041d28d92314f
	#
	# This is a basic heartbeat monitoring script suitible for adding to
	# a machine's crontab to receive alerts (via https://healthchecks.io)
	# when the machine is unhealthy.
	#
	# I use it to keep an eye on my headless Raspberry Pi, but it should
	# work for most Linux machines.
	#

	#!/bin/bash
	# Queries the given Healthchecks.io project/tags, and sets a blink(1)
	# based on the results.
	#
	# Suggest running once per minute via cron.

	URL_F='https://healthchecks.io/badge/%s.json'
	all_counts=()

	blink() {

	#!/bin/bash
	#
	# Helper utility to simplify using Bash's getopts utility, and make it usable with functions.
	#
	# Example usage:
	# foo() {
	# local _usage=... # optional usage string
	# eval "$(parse_opts 'ab:f:v')" # provide a standard getopts optstring
	# echo "f is $f" # opts are now local variables
	# if (( a )); then # check boolean flags with (( ... ))

	#!/bin/bash
	# Checks that a Plex server is up. For devices on a local network your
	# router may have created [hostname].local or [hostname].lan DNS entries;
	# otherwise you can pass an IP address or ensure your server is remotely
	# accessible (https://support.plex.tv/articles/200931138/).
	#
	# See also
	# https://old.reddit.com/r/PleX/comments/7qolre/what_do_others_do_to_monitor_plex_health/
	# https://support.plex.tv/articles/201638786-plex-media-server-url-commands/
	#

Michael Diamond dimo414

Expanding Bash arrays safely with set -u

Setup

Expanding Bash arrays safely with `set -u`