in lib/logstash/outputs/amazon_es/http_client/pool.rb [204:227]
def sniff_2x_1x(nodes)
nodes.map do |id,info|
addr_str = info['http_address'].to_s
next unless addr_str
attributes = info['attributes']
next if attributes && attributes['data'] == 'false'
matches = addr_str.match(ES1_SNIFF_RE_URL) || addr_str.match(ES2_SNIFF_RE_URL)
if matches
host = matches[1].empty? ? matches[2] : matches[1]
port = matches[3]
::LogStash::Util::SafeURI.new("#{host}:#{port}")
end
end.compact
end