dimo414

#!/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.
#

dimo414

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

dimo414

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.

dimo414

#!/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 (( ... ))

dimo414

<?php

/*
Enables a PHP page to abstract out the site design (the template) from
the page design (the content).

Generally, a page will have a common header and footer (sidebars and the
like would live in one or the other).  Following this pattern, a new page
can be created (after including the necessary files of course)) like so:

dimo414

class DefaultCapturingNamespace(argparse.Namespace):
  """An argparse Namespace that tracks the number of times the given argument
  has been set. In theory this can allow you to distinguish between values
  set by argparse (e.g. default values) and those specified by the user.
  """
  def __init__(self, **kwargs):
    type_name = type(self).__name__
    argparse.Namespace.__setattr__(self, '_%s__original_values' % type_name, {})
    argparse.Namespace.__setattr__(self, '_%s__set_counts' % type_name, {})

dimo414

#!/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() {

dimo414

#!/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/
#

dimo414

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * Runnable which causes a heavy yet stable amount of GC; useful for
 * benchmarking applications under load.
 * 

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