abhishek77in

Database do's and don'ts

This is a generic guidline that applies mostly to Ruby on Rails and Postgres, but can be usefull for running any database migrations in CI.

Table of contents

• Table of contents
• Zero downtime migrations
  • Resources
• Basic tenets

abhishek77in

def flatten_hash(hash, results = {}, parent_key = '')
  return results unless hash.kind_of?(Hash)

  hash.keys.each do |key|
    # current_key = "#{parent_key}[#{key}]" # uncomment this if you want to keep parent key as a partof key for flattened hash (csv column name)
    current_key = key
    if hash[key].kind_of?(Hash)
      results = flatten_hash(hash[key], results, current_key)
    else
      if hash[key].kind_of?(Array)

abhishek77in

require 'resolv'

url = 'www.diagnofy.in'
begin
  r = Resolv::DNS.open do |dns|
    dns.timeouts = 1
    dns.getresource(url, Resolv::DNS::Resource::IN::CNAME)
  end
  r.name.to_s # => return alias domain
rescue Resolv::ResolvError => e

abhishek77in

#!/bin/bash
sudo apt update
sudo apt install -y debian-keyring debian-archive-keyring apt-transport-https
curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/gpg.key' | sudo gpg --dearmor -o /usr/share/keyrings/caddy-stable-archive-keyring.gpg
curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/debian.deb.txt' | sudo tee /etc/apt/sources.list.d/caddy-stable.list
sudo apt update
sudo apt install caddy
caddy version
sudo systemctl status caddy
sudo systemctl enable caddy

abhishek77in

namespace :db do  desc "Backup database to AWS-S3"
  task :backup => [:environment] do
    datestamp = Time.now.strftime("%Y-%m-%d_%H-%M-%S")
    backup_filename = "#{Rails.root.basename}-#{datestamp}.sql"
    db_config = ActiveRecord::Base.configurations[Rails.env]

    # process backup
    `mysqldump -u #{db_config['username']} -p#{db_config['password']} -i -c -q #{db_config['database']} > tmp/#{backup_filename}`
    `gzip -9 tmp/#{backup_filename}`
    puts "Created backup: #{backup_filename}"

abhishek77in

require "prawn"

Prawn::Document.generate("report.pdf") do

    10.times do
        start_new_page
    end

    repeat :all do
        move_down 50

abhishek77in

#!/bin/bash

# -----------------------------------------------------------------------
# Installs Ruby 2.3 using rbenv/ruby-build on the Raspberry Pi (Raspbian)
#
# Run from the web:
#   bash <(curl -s raw_script_url_here)
# -----------------------------------------------------------------------

# Set up variables

abhishek77in

heroku pg:backups:capture --app sushi
curl -o latest.dump `heroku pg:backups public-url --app sushi`
curl -o latest.dump `heroku pg:backups:url b001 --app sushi`
pg_restore --verbose --clean --no-acl --no-owner -d <app_name>_development latest.dump

# Restore data from trial server
curl -o latest.dump `heroku pg:backups public-url --app labsmart-trial`
be rake db:drop db:create
pg_restore --verbose --clean --no-acl --no-owner -d azurite_development latest.dump

abhishek77in

var printPage = (function () {
    var style = document.createElement('style');
  $(".columns").append(style)
    return function (rule) {
        style.innerHTML = rule;
    };
}());

printPage.size = function (marginTop) {
    printPage('@media print { @page {margin-top: ' + marginTop + 'cm} }');

abhishek77in

user  nginx;
worker_processes  5;

error_log  /var/log/nginx.error.log;
pid        /var/run/nginx.pid;

events {
  worker_connections  1024;
}