Vipul Vaidya vipulvv

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

Preparation for CKA with Kubernetes version 1.17.1 on REDHAT 8

What i need to know for the exam ? 🏁

%	Domain
08%	Application Lifecycle Management
12%	Installation, Configuration & Validation
19%	Core Concepts
11%	Networking

Google dork cheatsheet

Search filters

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Assembly (x86_64)

Useful quick references

General:

Resources

KUBERNETES CLUSTER

local https://github.com/kubernetes-sigs/kind (or just use minikube if it works for you)
cloud https://cloud.google.com/kubernetes-engine (for PersistentVolume and Ingress, I needed to try the real deal)
practice environment: https://github.com/arush-sal/cka-practice-environment

PRACTICE

Ansible for Configuration Management

I'm using Ansible only for Configuration Management, the server is up and I want to configure users, install packages and configure them.

For infrastructure provisioning terraform.io is nice!

Currently, my deployment flow includes Drone.io/GitlabCI for CI/CD and Docker Swarm for orchestrating containers.

Ansible for Configuration Management
Tasks

	"""gunicorn configuration file to export server metrics

	To launch add `-c webapp/gunicorn_config.py` to the gunicorn command line.
	Requires statsd to be configured for gunicorn as well, e.g.
	`ENV STATSD_HOST=statsd-exporter:9125`

	"""

	# Python imports
	import ctypes


	FILE SPACING:

	# double space a file
	sed G

	# double space a file which already has blank lines in it. Output file
	# should contain no more than one blank line between lines of text.
	sed '/^$/d;G'

	#!/usr/bin/python
	from bcc import BPF
	from time import sleep

	# This outputs a count of how many times the clone and execve syscalls have been made
	# showing the use of an eBPF map (called syscall).

	program = """
	BPF_HASH(syscall);