lib/lusnoc/watcher.rb
require 'timeouter'
require 'lusnoc/exceptions'
require 'lusnoc/helper'
module Lusnoc
class Watcher
include Helper
def initialize(base_url,
timeout: 0,
eclass: Lusnoc::TimeoutError,
emessage: 'watch timeout')
@base_url = base_url
@timeout = timeout
@eclass = eclass
@emessage = emessage
end
# run Consul blocking request in a loop with timeout support.
# break condition yielded by block call with response body
def run(max_consul_wait: nil)
logger.debug "Watch #{@base_url} with #{@timeout.inspect} timeout"
last_x_consul_index = 1
Timeouter.loop!(@timeout, eclass: @eclass, message: @emessage) do |t|
wait_condition = build_wait_condition(@base_url, t.left, max_consul_wait)
url = "#{@base_url}?index=#{last_x_consul_index}#{wait_condition}"
resp = Lusnoc.http_get(url, timeout: t.left)
return true if yield(resp.body)
logger.debug "Watch #{@base_url} response: #{resp.body}"
index = [Integer(resp['x-consul-index']), 1].max
last_x_consul_index = (index < last_x_consul_index ? 1 : index)
sleep 0.4
end
end
def build_wait_condition(_url, time_left, max_consul_wait)
if time_left
max = [time_left.to_i, max_consul_wait.to_i].max
"&wait=#{max}s"
elsif max_consul_wait
"&wait=#{max_consul_wait.to_i}s"
else
''
end
end
end
end