Daniel Michaels danielmichaels

2019 update: this essay has been updated on my personal site, together with a followup on how to get started

2020 update: I'm now writing a book with updated versions of all these essays and 35 other chapters!!!!

1. Learn in public

If there's a golden rule, it's this one, so I put it first. All the other rules are more or less elaborations of this rule #1.

You already know that you will never be done learning. But most people "learn in private", and lurk. They consume content without creating any themselves. Again, that's fine, but we're here to talk about being in the top quintile. What you do here is to have a habit of creating learning exhaust. Write blogs and tutorials and cheatsheets. Speak at meetups and conferences. Ask and answer things on Stackoverflow or Reddit. (Avoid the walled gardens like Slack and Discourse, they're not public). Make Youtube videos

Create a service file like dash_sniffer.service
Put it in /lib/systemd/system/
Reload systemd using command: systemctl daemon-reload
Enable auto start using command: systemctl enable dash_sniffer.service

If anyone is interested in setting up their system to automatically (or manually) sign their git commits with their GPG key, here are the steps:

Generate and add your key to GitHub
$ git config --global commit.gpgsign true ([OPTIONAL] every commit will now be signed)
$ git config --global user.signingkey ABCDEF01 (where ABCDEF01 is the fingerprint of the key to use)
$ git config --global alias.logs "log --show-signature" (now available as $ git logs)
$ git config --global alias.cis "commit -S" (optional if global signing is false)
$ echo "Some content" >> example.txt
$ git add example.txt
$ git cis -m "This commit is signed by a GPG key." (regular commit will work if global signing is enabled)

Virtual Hosts on nginx (CSC309)

When hosting our web applications, we often have one public IP address (i.e., an IP address visible to the outside world) using which we want to host multiple web apps. For example, one may wants to host three different web apps respectively for example1.com, example2.com, and example1.com/images on the same machine using a single IP address.

How can we do that? Well, the good news is Internet browsers

	###############################################################################
	# Author: ddnomad
	# Version: 1.1.3
	# Last Update: 2020-07-06
	#
	# External contributors:
	# - u/momasf (https://www.reddit.com/user/momasf) - an excellent
	# tip to use 'reflector' to speed up downloads during the base
	# installation
	# - eXhumer (https://github.com/eXhumer) - Fixes for things that

	// tweaked from: https://stackoverflow.com/a/42718113/1170664
	func getXML(url string) ([]byte, error) {
	resp, err := http.Get(url)
	if err != nil {
	return []byte{}, fmt.Errorf("GET error: %v", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
	return []byte{}, fmt.Errorf("Status error: %v", resp.StatusCode)

	# import config.
	# You can change the default config with `make cnf="config_special.env" build`
	cnf ?= config.env
	include $(cnf)
	export $(shell sed 's/=.*//' $(cnf))

	# import deploy config
	# You can change the default deploy config with `make cnf="deploy_special.env" release`
	dpl ?= deploy.env
	include $(dpl)

	// fileResponseWriter wraps an http.ResponseWriter and a File
	// passing it to an http.Handler's ServeHTTP
	// will write to both the file and the response.

	type fileResponseWriter struct {
	file io.Writer
	resp http.ResponseWriter
	multi io.Writer
	}

	# This is just a cheat sheet:

	# On production
	sudo -u postgres pg_dump database \| gzip -9 > database.sql.gz

	# On local
	scp -C production:~/database.sql.gz
	dropdb database && createdb database
	gunzip < database.sql.gz \| psql database

-# delete local tag '12345'
-git tag -d 12345
-# delete remote tag '12345' (eg, GitHub version too)
-git push origin :refs/tags/12345
-# alternative approach
-git push --delete origin tagName
-git tag -d tagName