Refactoring check-consumer-lag to remove shell/jvm execution

.travis.yml

@@ -1,11 +1,12 @@
 language: ruby
+
 cache:
   - bundler
+
 install:
   - bundle install
+
 rvm:
-  - 2.1
-  - 2.2.1
   - 2.3.0
 
 script:

CHANGELOG.md

@@ -10,6 +10,11 @@ This CHANGELOG follows the format listed at [Keep A Changelog](http://keepachang
 ### Fixed
 ### Changed
 
+## [Unreleased]
+
+### Breaking Changes
+- Refactoring check-consumer-lag to remove shell/jvm execution
+
 ## [0.7.0]
 
 ### Added

bin/check-consumer-lag.rb

@@ -27,118 +27,110 @@
 
 require 'sensu-plugin/check/cli'
 
+require 'celluloid-io'
+require 'json'
+require 'poseidon'
+require 'zookeeper'
+
+module Poseidon
+  class Connection
+    TCPSocket = Celluloid::IO::TCPSocket
+  end
+end
+
 class ConsumerLagCheck < Sensu::Plugin::Check::CLI
   option :group,
          description: 'Consumer group',
          short:       '-g NAME',
          long:        '--group NAME',
          required:    true
 
-  option :kafka_home,
-         description: 'Kafka home',
-         short:       '-k NAME',
-         long:        '--kafka-home NAME',
-         default:     '/opt/kafka'
-
-  option :topic_excludes,
-         description: 'Excludes consumer topics',
-         short:       '-e NAME',
-         long:        '--topic-excludes NAME',
-         proc:        proc { |a| a.split(',') }
-
-  option :autolist,
-         description: 'Auto list topics',
-         short:       '-a VALUE',
-         long:        '--auto-list VALUE',
-         boolean: true,
-         default: true
-
   option :zookeeper,
          description: 'ZooKeeper connect string',
          short:       '-z NAME',
          long:        '--zookeeper NAME',
          default:     'localhost:2181'
 
   option :warning_over,
-         description: 'Warning if metric statistics is over specified value.',
+         description: 'Warning if lag is over specified value.',
          short:       '-W N',
          long:        '--warning-over N'
 
   option :critical_over,
-         description: 'Critical if metric statistics is over specified value.',
+         description: 'Critical if lag is over specified value.',
          short:       '-C N',
          long:        '--critical-over N'
 
   option :warning_under,
-         description: 'Warning if metric statistics is under specified value.',
+         description: 'Warning if lag is under specified value.',
          short:       '-w N',
          long:        '--warning-under N'
 
   option :critical_under,
-         description: 'Critical if metric statistics is under specified value.',
+         description: 'Critical if lag is under specified value.',
          short:       '-c N',
          long:        '--critical-under N'
 
-  # read the output of a command
-  # @param cmd [String] the command to read the output from
-  def read_lines(cmd)
-    IO.popen(cmd + ' 2>&1') do |child|
-      child.read.split("\n")
-    end
+  def kafka_topics(zk, group)
+    zk.get_children(path: "/consumers/#{group}/owners")[:children].sort
   end
 
-  # create a hash from the output of each line of a command
-  # @param line [String]
-  # @param cols
-  def line_to_hash(line, *cols)
-    Hash[cols.zip(line.strip.split(/\s+/, cols.size))]
+  def topics_partitions(zk, topic)
+    JSON.parse(zk.get(path: "/brokers/topics/#{topic}")[:data])['partitions'].keys.map(&:to_i).sort
   end
 
-  # run command and return a hash from the output
-  # @param cmd [String]
-  def run_offset(cmd)
-    read_lines(cmd).drop(1).map do |line|
-      line_to_hash(line, :group, :topic, :pid, :offset, :logsize, :lag, :owner)
-    end
+  def leader_broker(zk, topic, partition)
+    state = zk.get(path: "/brokers/topics/#{topic}/partitions/#{partition}/state")
+    leader = JSON.parse(state[:data])['leader']
+    JSON.parse(zk.get(path: "/brokers/ids/#{leader}")[:data])
   end
 
-  # run command and return a hash from the output
-  # @param cmd [String]
-  def run_topics(cmd)
-    topics = []
-    read_lines(cmd).map do |line|
-      if !line.include?('__consumer_offsets') && !line.include?('marked for deletion')
-        topics.push(line)
-      end
-    end
-    topics
+  def consumer_offset(zk, group, topic, partition)
+    zk.get(path: "/consumers/#{group}/offsets/#{topic}/#{partition}")[:data].to_i
+  end
+
+  def partition_owner(zk, group, partition)
+    zk.get(path: "/consumers/#{group}/offsets/#{owners}/#{partition}")[:data]
   end
 
   def run
-    kafka_run_class = "#{config[:kafka_home]}/bin/kafka-run-class.sh"
-    unknown "Can not find #{kafka_run_class}" unless File.exist?(kafka_run_class)
-
-    topics_to_read = []
-    if config[:autolist].to_s == 'true'
-      cmd_topics = "#{kafka_run_class} kafka.admin.TopicCommand --zookeeper #{config[:zookeeper]} --list"
-      topics_to_read = run_topics(cmd_topics)
-      topics_to_read.delete_if { |x| config[:topic_excludes].include?(x) } if config[:topic_excludes]
-    end
+    z = Zookeeper.new(config[:zookeeper])
+
+    group = config[:group]
+    topics = kafka_topics(z, group)
+
+    critical 'Could not found topics' if topics.empty?
+
+    consumers = {}
+    topics.each do |topic|
+      consumers[topic] = {}
 
-    cmd_offset = "#{kafka_run_class} kafka.tools.ConsumerOffsetChecker --group #{config[:group]} --zookeeper #{config[:zookeeper]}"
-    cmd_offset += " --topic #{topics_to_read.join(',')}" unless topics_to_read.empty?
+      topics_partitions(z, topic).each do |partition|
+        owner = partition_owner(z, group, partition)
 
-    topics = run_offset(cmd_offset).group_by { |h| h[:topic] }
+        leader = leader_broker(z, topic, partition)
+        consumer = Poseidon::PartitionConsumer.new('CheckConsumerLag', leader['host'], leader['port'], topic, partition, :latest_offset)
+        logsize = consumer.next_offset
 
-    critical 'Could not found topics/partitions' if topics.empty?
+        offset = consumer_offset(z, group, topic, partition)
+
+        lag = logsize - offset
+
+        consumers[topic][:partition] = partition
+        consumers[topic][:logsize] = logsize
+        consumers[topic][:offset] = offset
+        consumers[topic][:lag] = lag
+        consumers[topic][:owner] = owner
+      end
+    end
 
     [:offset, :logsize, :lag].each do |field|
-      topics.map do |k, v|
+      consumers.map do |k, v|
         critical "Topic #{k} has partitions with #{field} < 0" unless v.select { |w| w[field].to_i < 0 }.empty?
       end
     end
 
-    topics.map do |k, v|
+    consumers.map do |k, v|
       critical "Topic #{k} has partitions with no owner" unless v.select { |w| w[:owner] == 'none' }.empty?
     end
 
@@ -165,7 +157,7 @@ def run
           end
         when :under
           if min_lag < threshold.to_i
-            msg =  "Topics `#{min_topics}` for the group `#{config[:group]}` lag: #{min_lag} (<= #{threshold})"
+            msg = "Topics `#{min_topics}` for the group `#{config[:group]}` lag: #{min_lag} (<= #{threshold})"
             send severity, msg
           end
         end

sensu-plugins-kafka.gemspec

@@ -34,6 +34,8 @@ Gem::Specification.new do |s|
   s.test_files             = s.files.grep(%r{^(test|spec|features)/})
   s.version                = SensuPluginsKafka::Version::VER_STRING
 
+  s.add_runtime_dependency 'celluloid-io',      '~> 0.17.3 '
+  s.add_runtime_dependency 'poseidon',          '0.0.5'
   s.add_runtime_dependency 'sensu-plugin',      '~> 1.3'
   s.add_runtime_dependency 'zookeeper',         '~> 1.4.11'