A (slightly offensive) set of rake tasks for backing up, listing backups and restoring backups for a pg rails app (with checks to ensure server and console aren't running before performing restore)

db.rake

namespace :db do

  task :backup => :environment do
    db = ActiveRecord::Base.connection_config[:database]
    file = Rails.root.join("db", "backups", "#{Time.now.strftime("%Y%m%d%H%M%S")}_#{db}.psql")

    puts "Preparing to back yo shit up....\ngimme dat password fool:"
    system "pg_dump -F c -v -h localhost -d #{db} -f #{file}"
    puts "\nI done stuffed your worthless data in #{file}\n"
  end

  task :list_backups => :environment do 
    db_folder = Rails.root.join("db", "backups")
    backups = Dir.entries(db_folder).select{|i| i.match(/.psql$/)}.sort.reverse
    
    puts "\nbitch you got these backups available (most recent first yo);\n\n"
    backups.each_with_index do |backup, index|
      gap = Array.new([backups.size.to_s.length-index.to_s.length, 0].max){" "}.join
      puts "[#{index}]#{gap}- #{backup}"
    end
    puts "\nrun rake db:restore[x]\nwhere x is one of the muthafuckin' numbers in the [] above, or don't, whatever\n"
  end

  task :restore, [:n] => :environment do |task, args|
    db_folder = Rails.root.join("db", "backups")
    backups = Dir.entries(db_folder).select{|i| i.match(/.psql$/)}.sort.reverse

    go_no_go = true

    #check is rails server is running and hurl abuse if it is
    server_running  = !Dir.entries(Rails.root.join("tmp", "pids")).select{|i| i.match(/.pid$/)}.empty?
    if server_running 
      puts "\nare you stupid?! The server is still running. Shut that shit down first!!"
      go_no_go = false      
    end

    #check if a console exists and give user option to stop or carry on
    console_running = !(`ps auxwww | grep rails_console`).split("\n").select{|l| !l.include?("grep")}.empty?
    if go_no_go && console_running 
      puts "\nA rails console is still running. maybe it's console from another app, but given your incompetance it's probably attached to this one's DB so ya gotta shut it down\nIf it's another console hit 'y' to continue"
      go_no_go = STDIN.gets.chomp.downcase.eql?("y")
    end

    if go_no_go
      puts "\nbitch you didn't specify a number to restore, what am I telepathic? fuck it, I'll just restore the most recent one\n" unless args.n
      n = args.n.to_i #if arg.n is nil calling to_i will result in 0.
      restore = backups[n]      
    end
    
    #halt if backup file can't be found
    if go_no_go && restore.nil?
      puts "\nI couldn't find a database to restore, bitch"
      go_no_go = false
    end

    #double check before actually doing the deed.
    if go_no_go
      puts "\nso, like...gonna restore this one - #{restore} - whack 'y' to confirm"
      go_no_go = STDIN.gets.chomp.downcase.eql?("y")
    end

    if go_no_go
      db = ActiveRecord::Base.connection_config[:database]
      Rake::Task["db:drop"].invoke
      Rake::Task["db:create"].invoke
      file = Rails.root.join("db", "backups", restore)
      #system "pg_restore -F c -c -C #{file}" <--slower than drugged sloth
      system "pg_restore --dbname #{db} -v #{file}" #<-- this is much faster
    end

  end

end