atitan

#! /usr/bin/env python
import re, fileinput, tempfile
from optparse import OptionParser


IGNOREDPREFIXES = [
    'PRAGMA',
    'BEGIN TRANSACTION;',
    'COMMIT;',
    'DELETE FROM sqlite_sequence;',

atitan

++


(´◓Д◔`) 哇幹!!
(　っค้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้c )

++
(´◓Д◔`) 哇幹!!
(　っค้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้้c )
++

atitan

#!/bin/sh
## backup each mysql db into a different file, rather than one big file
## as with --all-databases. This will make restores easier.
## To backup a single database simply add the db name as a parameter (or multiple dbs)
 
## Putting the script in /var/backups/mysql seems sensible... on a debian machine that is
## Create the user and directories
# mkdir -p /var/backups/mysql/databases
# useradd --home-dir /var/backups/mysql --gid backup --no-create-home mysql-backup
## Remember to make the script executable, and unreadable by others

atitan

#!/bin/bash

# get the latest linux kernel at http://kernel.ubuntu.com/~kernel-ppa/mainline/
wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.14-rc6/linux-image-4.14.0-041400rc6-generic_4.14.0-041400rc6.201710230731_amd64.deb

# install the kernel
dpkg -i linux-image-4.*.deb

# update grub
# for linode, change kernel in boot settings to GRUB 2

atitan

Processing JSON using jq

jq is useful to slice, filter, map and transform structured json data.

Installing jq

On Mac OS

brew install jq

atitan

JQ to filter JSON by value

Syntax: cat <filename> | jq -c '.[] | select( .<key> | contains("<value>"))'

Example: To get json record having _id equal 611

cat my.json | jq -c '.[] | select( ._id | contains(611))'

Remember: if JSON value has no double quotes (eg. for numeric) to do not supply in filter i.e. in contains(611)

atitan

Setup redis-cli on AWS EC2

SSH into your EC2 instance. Run the following:

$ sudo yum install gcc This may return an "already installed" message. That's OK.

$ wget http://download.redis.io/redis-stable.tar.gz && tar xvzf redis-stable.tar.gz && cd redis-stable && make

See: http://docs.aws.amazon.com/AmazonElastiCache/latest/UserGuide/GettingStarted.ConnectToCacheNode.Redis.html

atitan

require 'cgi'
require 'json'
require 'active_support'

def verify_and_decrypt_session_cookie(cookie, secret_key_base)
  cookie = CGI::unescape(cookie)
  salt         = 'encrypted cookie'
  signed_salt  = 'signed encrypted cookie'
  key_generator = ActiveSupport::KeyGenerator.new(secret_key_base, iterations: 1000)
  secret = key_generator.generate_key(salt)[0, ActiveSupport::MessageEncryptor.key_len]

atitan

#!/bin/bash

yum install -y jq curl

while sleep 5; do
  if [ -z $(curl -Isf http://169.254.169.254/latest/meta-data/spot/instance-action) ]; then
    /bin/false
  else
    EC2_INSTANCE_ID=$(curl -s http://169.254.169.254/latest/meta-data/instance-id)
    EC2_AVAIL_ZONE=`curl -s http://169.254.169.254/latest/meta-data/placement/availability-zone`

atitan

Problem

Installing mysql2 gem errors on MacOS Mojave.

Solution

Make sure openssl is installed on Mac via Homebrew.

brew install openssl