Imran Hayder imranity

terraform config for MWAA

Support Version

https://github.com/hashicorp/terraform-provider-aws/releases/tag/v3.36.0

Plan & Apply

terraform plan -var-file=vars.tfvars
terraform apply -var-file=vars.tfvars

Getting a shell on each node

I run several K8S cluster on EKS and by default do not setup inbound SSH to the nodes. Sometimes I need to get into each node to check things or run a one-off tool.

Rather than update my terraform, rebuild the launch templates and redeploy brand new nodes, I decided to use kubernetes to access each node directly.

Alternative option

https://github.com/alexei-led/nsenter

What to Expect and Tips

• 45-minute systems interview, focus on responding to real world problems with an unhealthy service, such as a web server or database. The interview will start off at a high level troubleshooting a likely scenario, dig deeper to find the cause and some possible solutions for it. The goal is to probe your knowledge of systems at scale and under load, so keep in mind the challenges of the Facebook environment.
• Focus on things such as tooling, memory management and unix process lifecycle.

Systems

More specifically, linux troubleshooting and debugging. Understanding things like memory, io, cpu, shell, memory etc. would be pretty helpful. Knowing how to actually write a unix shell would also be a good idea. What tools might you use to debug something? On another note, this interview will likely push your boundaries of what you know (and how to implement it).

Design/Architecture

Interview is all about taking an ambiguous question of how you might build a system and letting

https://explainshell.com/

Find the largest file in a directory and its subdirectories using the find command & more

find . -printf '%s %p\n'| sort -nr | head -10

@see https://www.cyberciti.biz/faq/how-do-i-find-the-largest-filesdirectories-on-a-linuxunixbsd-filesystem/

Show host IP address for a specific domain

AWK

Get users with uid > 1000

awk -F'[/:]' '{if ($3 >= 1000 && $3 != 65534) print $1}' /etc/passwd

Grep

Links:

http://najomi.org/_nix/grep

https://stackoverflow.com/questions/48993286/is-it-possible-to-route-traffic-to-a-specific-pod?rq=1

You can guarantee session affinity with services, but not as you are describing. So, your customers 1-1000 won't use pod-1, but they will use all the pods (as a service makes a simple load balancing), but each customer, when gets back to hit your service, will be redirected to the same pod.

Note: always within time specified in (default 10800):

	# Source: https://gist.github.com/b0a32051da5ae3dea09e596689d7cf24

	#################################
	# Running Jenkins In Kubernetes #
	# Tutorial And Review #
	# https://youtu.be/2Kc3fUJANAc #
	#################################

	# Referenced videos:
	# - GitHub CLI - How to manage repositories more efficiently: https://youtu.be/BII6ZY2Rnlc

	# extraction pattern: ngram TAB year TAB match_count TAB volume_count NEWLINE
	# out: unique_ngram TAB sum(match_count) NEWLINE

	import re
	import os, sys, mmap
	from pathlib import Path
	from tqdm import tqdm
	from concurrent.futures import ThreadPoolExecutor

	abv = re.compile(r'^(([A-Z]\.){1,})(_\|[^\w])') # A.B.C.

	apiVersion: elasticsearch.k8s.elastic.co/v1
	kind: Elasticsearch
	metadata:
	name: elasticsearch
	spec:
	version: 7.5.1
	nodeSets:
	- name: default
	count: 3
	config:

	#!/bin/bash

	# IMPORTANT: Don't forget to logout from your Apple ID in the settings before running it!
	# IMPORTANT: You will need to run this script from Recovery. In fact, macOS Catalina brings read-only filesystem which prevent this script from working from the main OS.
	# This script needs to be run from the volume you wish to use.
	# E.g. run it like this: cd /Volumes/Macintosh\ HD && sh /Volumes/Macintosh\ HD/Users/sabri/Desktop/disable.sh
	# WARNING: It might disable things that you may not like. Please double check the services in the TODISABLE vars.

	# Get active services: launchctl list \| grep -v "\-\t0"
	# Find a service: grep -lR [service] /System/Library/Launch* /Library/Launch* ~/Library/LaunchAgents