Maxim Prototype-X

README

Timers provided by systemd can be used as cronjob replacements. More at man systemd.timer.

Suppose we want to periodically trigger cleanup tasks for a baz utility. We 'll create a baz-cleanup.service which will be triggered by a baz-cleanup.timer.

Define the target service unit

Create a minimal service at /etc/systemd/system/baz-cleanup.service:

TL;DR

Install Postgres 9.5, and then:

sudo pg_dropcluster 9.5 main --stop
sudo pg_upgradecluster 9.3 main
sudo pg_dropcluster 9.3 main

tmux vs. screen commands

Action	tmux	screen
start a new session	`tmux` `tmux new` `tmux new-session`	`screen`
start a new session with a name	`tmux new -s name`	`screen -S name`
re-attach a detached session	`tmux attach` `tmux attach-session`	`screen -r`
re-attach a detached session with a name	`tmux attach -t name` `tmux a -t name`	`screen -r name`
re-attach an attached session (detaching it from elsewhere)	tmux attach -dtmux attach-session -d	screen -dr

#Container Resource Allocation Options in docker-run

now see: https://docs.docker.com/engine/reference/run/#runtime-constraints-on-resources

You have various options for controlling resources (cpu, memory, disk) in docker. These are principally via the docker-run command options.

##Dynamic CPU Allocation -c, --cpu-shares=0
CPU shares (relative weight, specify some numeric value which is used to allocate relative cpu share)

Signal	Value	Action	Comment
SIGHUP	1	Term	Hangup detected on controlling terminal or death of controlling process
SIGINT	2	Term	Interrupt from keyboard
SIGQUIT	3	Core	Quit from keyboard
SIGILL	4	Core	Illegal Instruction
SIGABRT	6	Core	Abort signal from abort(3)
SIGFPE	8	Core	Floating point exception
SIGKILL	9	Term	Kill signal
SIGSEGV	11	Core	Invalid memory reference
SIGPIPE	13	Term	Broken pipe: write to pipe with no readers

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)

	#!/bin/sh

	# set hostname
	echo <%= hostname %> > /etc/hostname
	/etc/init.d/hostname.sh

	# Set up networking
	cat > /etc/network/interfaces << EOF
	# The loopback network interface
	auto lo

	##TCP FLAGS##

	Unskilled Attackers Pester Real Security Folks
	==============================================
	TCPDUMP FLAGS
	Unskilled = URG = (Not Displayed in Flag Field, Displayed elsewhere)
	Attackers = ACK = (Not Displayed in Flag Field, Displayed elsewhere)
	Pester = PSH = [P] (Push Data)
	Real = RST = [R] (Reset Connection)
	Security = SYN = [S] (Start Connection)

	#!/bin/bash
	#####################################################
	# Name: Bash CheatSheet for Mac OSX
	#
	# A little overlook of the Bash basics
	#
	# Usage:
	#
	# Author: J. Le Coupanec
	# Date: 2014/11/04

	/* Useful celery config.

	app = Celery('tasks',
	broker='redis://localhost:6379',
	backend='redis://localhost:6379')

	app.conf.update(
	CELERY_TASK_RESULT_EXPIRES=3600,
	CELERY_QUEUES=(
	Queue('default', routing_key='tasks.#'),