Neurostep

var Rx = require("rx");

var o = Rx.Observable.interval(100)
		.take(10)
		.map(function(x) { if (x % 3 === 1) { throw x; } else { return x; } })
		.retry(2)
    .subscribe(function(a) { console.log("BBB", a); });

Neurostep

const bufferSize = 2
const startEvery = 1 // also tried -1, 0, 1, 3

Rx.Observable.of(1,2,3,4,5)
  .bufferCount(bufferSize, startEvery)
	.filter(function(x) { return x.length > 1; })
  .subscribe(console.log.bind(console));

Neurostep

/*
* Function flattens the nested array of Ints
*
* @param {Array} array
* Array (possibly nested) of Ints
*
* @return {Array}
* Return's flatten Arrays of Ints
*
* testFlatten :: Array(Array Int) -> Array Int

Neurostep

Table of Contents

• References
• Other cheatsheets
• multiple gcloud config configurations
  • switch gcloud context with gcloud config
• auth
• info
• projects
• zones

Neurostep

PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h or --help depending on your psql version):

• -E: will describe the underlaying queries of the \ commands (cool for learning!)
• -l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)

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cheatsheet

• https://prefetch.net/blog/2019/10/16/the-beginners-guide-to-creating-kubernetes-manifests/
• https://gist.github.com/constantlycoding/220f0dcb4aef8b0a14d4f336f0b102b1
• https://kubernetes.io/docs/user-guide/kubectl-cheatsheet/
• https://learnk8s.io/blog/kubectl-productivity/
• https://medium.com/faun/kubectl-commands-cheatsheet-43ce8f13adfb
• https://gist.github.com/so0k/42313dbb3b547a0f51a547bb968696ba
• https://speakerdeck.com/so0k/kubectl-tips-and-tricks
• https://github.com/dennyzhang/cheatsheet-kubernetes-A4
• https://medium.com/bitnami-perspectives/imperative-declarative-and-a-few-kubectl-tricks-9d6deabdde

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## Useful Commands

Get kubectl version

    kubectl version

Get cluster info:

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# find the kube node of the running pod, appear next to hostIP, and note containerID hash
kubectl get pod mypod -o json
# -> save hostIP
# -> save containerID

# connect to the node and find the pods unique network interface index inside it's container
docker exec containerID /bin/bash -c 'cat /sys/class/net/eth0/iflink'
# -> returns index

# locate the interface of the node

Neurostep

Hopefully helped another k8s newbie with the following. The question was, how do you update a single key in a secret in k8s? I don't know anything about secrets but I will probably want to know this in the future, so here we go.

First, to create a dummy secret:

apiVersion: v1
kind: Secret
metadata:
  name: test-secret
data:

Neurostep

tcpdump advanced filters
========================

Sebastien Wains <sebastien -the at sign- wains -dot- be>
http://www.wains.be

$Id: tcpdump_advanced_filters.txt 36 2013-06-16 13:05:04Z sw $


Notes :