Parse Atom feeds and display only entries from less than <delta> days ago. Useful for tracking software updates

feeds.rb

#!/usr/bin/env ruby

require "rss"
require "yaml"
require "getoptlong"

opts = GetoptLong.new(
  [ '--feeds', '-f', GetoptLong::REQUIRED_ARGUMENT ],
  [ '--delta', '-d', GetoptLong::REQUIRED_ARGUMENT ],
)

feeds = "feeds.yaml"
delta = 1

opts.each do |opt, arg|
  case opt
  when '--feeds'
    feeds = arg
  when '--delta'
    delta = arg.to_i
  end
end

begin
  config = YAML.load_file(File.realpath(feeds))
rescue Exception => e
  puts "Unable to load config file: #{e.message}"
  exit 1
end

results = Hash.new{|h,k| h[k] = []}

config[:feeds].map do |name, url|
  Thread.new do
    begin
      open(url) do |rss|
        feed = RSS::Parser.parse(rss)
        feed.entries.each do |entry|
          break if entry.updated.content < (Time.now - delta * 86400)
          results[name] << "#{entry.updated.content}: #{entry.title.content}. see #{entry.link.href}"
        end
      end
    rescue Exception => e
      puts "Failed to retrieve #{name} feed (#{e.message})"
    end
  end
end.each{|t| t.join}

results.each do |name, content|
  puts "## %s\n%s" % [name, content.join("\n")]
end

feeds.yaml

---
:feeds:
  Jenkins: https://github.com/jenkinsci/jenkins/releases.atom
  Postgres: https://github.com/postgres/postgres/releases.atom
  HAproxy: http://freecode.com/projects/haproxy/releases.atom
  Elasticsearch: https://github.com/elasticsearch/elasticsearch/releases.atom
  Lita: https://github.com/jimmycuadra/lita/releases.atom
  InfluxDB: https://github.com/influxdb/influxdb/releases.atom