#!/usr/bin/env ruby

require 'net/ftp'

SERVER = ""
LOGIN = ""
PASSWORD = ""

# First, dump the database.
filename = "database-#{Time.now.strftime("%Y-%m-%d-%H")}.sql"
command = "pg_dump 'postgres://user:password@server:port/db' > #{filename}"
result = system(command)

# Then save the dump over ftp.
Net::FTP.open(SERVER, LOGIN, PASSWORD) do |ftp|
  ftp.putbinaryfile(File.new(filename))
end

# Keep 10 backups on the backup server.
Net::FTP.open(SERVER, LOGIN, PASSWORD) do |ftp|
  files = ftp.nlst
  files.pop(10)
  files.each { |f| ftp.delete(f) }
end

# Keep 3 backups locally.
files = Dir.glob("database-*")
files.sort!
files.pop(3)
File.unlink(*files)