Rajaneesh Rajaneeshs

Docker - How to cleanup (unused) resources

Once in a while, you may need to cleanup resources (containers, volumes, images, networks) ...

delete volumes

// see: https://github.com/chadoe/docker-cleanup-volumes

$ docker volume rm $(docker volume ls -qf dangling=true)

$ docker volume ls -qf dangling=true | xargs -r docker volume rm

Moved to git repository: https://github.com/denji/nginx-tuning

NGINX Tuning For Best Performance

For this configuration you can use web server you like, i decided, because i work mostly with it to use nginx.

Generally, properly configured nginx can handle up to 400K to 500K requests per second (clustered), most what i saw is 50K to 80K (non-clustered) requests per second and 30% CPU load, course, this was 2 x Intel Xeon with HyperThreading enabled, but it can work without problem on slower machines.

You must understand that this config is used in testing environment and not in production so you will need to find a way to implement most of those features best possible for your servers.

tmux cheat sheet

(C-x means ctrl+x, M-x means alt+x)

Prefix key

The default prefix is C-b. If you (or your muscle memory) prefer C-a, you need to add this to ~/.tmux.conf:

remap prefix to Control + a

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

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname

How to generate a self-signed SAN SSL/TLS certificate using openssl

Generating a self-signed certificate is a common taks and the command to generate one with openssl is well known and well documented. Generating a certificate that includes subjectAltName is not so straght forward however. The following example demonstrates how to generate a SAN certificate without making a permanent change to the openssl configuration.

Generate a list of all required DNS names, (Note: CN will be discarded).

$ export SAN="DNS:www.domain.localdomain,DNS:domain.localdomain"

	-- show running queries (pre 9.2)
	SELECT procpid, age(query_start, clock_timestamp()), usename, current_query
	FROM pg_stat_activity
	WHERE current_query != '<IDLE>' AND current_query NOT ILIKE '%pg_stat_activity%'
	ORDER BY query_start desc;


	-- show running queries (9.2)
	SELECT pid, age(query_start, clock_timestamp()), usename, query
	FROM pg_stat_activity

	#!/usr/bin/env python

	import sys
	import boto
	import pprint

	del_flag = ''
	if len(sys.argv) > 1:
	del_flag = sys.argv[1]

	import re
	import boto3
	import csv
	from botocore.exceptions import ClientError

	ec2 = boto3.client('ec2')

	def get_snapshots():
	return ec2.describe_snapshots(OwnerIds=['self'])['Snapshots']

	#! /usr/bin/env python
	# -- coding: utf-8 --
	"""This module's docstring summary line.

	This is a multi-line docstring. Paragraphs are separated with blank lines.
	Lines conform to 79-column limit.

	Module and packages names should be short, lower_case_with_underscores.
	Notice that this in not PEP8-cheatsheet.py