Sandip Bhattacharya sandipb

Falsehoods programmers believe about time

This is a compiled list of falsehoods programmers tend to believe about working with time.

Don't re-invent a date time library yourself. If you think you understand everything about time, you're probably doing it wrong.

Falsehoods

There are always 24 hours in a day.
February is always 28 days long.
Any 24-hour period will always begin and end in the same day (or week, or month).

0.1. References
0.2. Other cheatsheets
0.3. Manage multiple gcloud config configurations
- 0.3.1. Switch gcloud context with gcloud config
0.4. Credentials
0.5. info
0.6. projects
0.7. zones & regions
0.8. Organization
0.9. billing

How to add a collapsible section in markdown

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Bar
- Baz

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I use PostgreSQL via the psql client. If you use a different client (eg. pgAdmin, etc.), I don't know how much will translate over.

One nice difference between psql and mysql (cli) is that if you press CTRL+C, it won't exit the client.

User administration

Login as superuser (via shell)

psql -U postgres

2021 Update: Easiest option is Justin's repo and image

Just run this from your Mac terminal and it'll drop you in a container with full permissions on the Docker VM. This also works for Docker for Windows for getting in Moby Linux VM (doesn't work for Windows Containers).

docker run -it --rm --privileged --pid=host justincormack/nsenter1

more info: https://github.com/justincormack/nsenter1

GitHub Flavored Asciidoc (GFA)

Create Root CA (Done once)

Create Root Key

Attention: this is the key used to sign the certificate requests, anyone holding this can sign certificates on your behalf. So keep it in a safe place!

openssl genrsa -des3 -out rootCA.key 4096

	# will not work in all cases, see https://gist.github.com/angelo-v/e0208a18d455e2e6ea3c40ad637aac53#gistcomment-3439904

	function jwt-decode() {
	sed 's/\./\n/g' <<< $(cut -d. -f1,2 <<< $1) \| base64 --decode \| jq
	}

	JWT=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiYWRtaW4iOnRydWV9.TJVA95OrM7E2cBab30RMHrHDcEfxjoYZgeFONFh7HgQ

	jwt-decode $JWT

	// For all the confusing Prometheus configuration and
	// regular expressions,
	// explained in examples.


	// Remember, there are default values for each item if it's missing.
	// regex is (.*),
	// replacement is $1,
	// separator is ;
	// ,and action is replace

	#Create storage
	VBoxManage createhd --filename VMName.vdi --size 40000 --format VDI

	VBoxManage modifyhd GoDial.vdi --resize 30500

	VBoxManage list hdds
	VBoxManage closemedium disk $(UUID) --delete

	#Create VM
	VBoxManage createvm --name "VMName" --ostype Windows7_64 --register