Merge pull request #51 from airbnb/next_release

Next release

Gemfile.lock

@@ -3,6 +3,8 @@ PATH
   specs:
     nerve (0.5.2)
       bunny (= 1.1.0)
+      etcd (~> 0.2.3)
+      json
       zk (~> 1.9.2)
 
 GEM
@@ -12,25 +14,28 @@ GEM
     bunny (1.1.0)
       amq-protocol (>= 1.9.2)
     diff-lcs (1.2.5)
+    etcd (0.2.3)
+      mixlib-log
+    json (1.8.1)
     little-plugger (1.1.3)
     logging (1.7.2)
       little-plugger (>= 1.1.3)
+    mixlib-log (1.6.0)
     rake (10.1.1)
     rspec (2.14.1)
       rspec-core (~> 2.14.0)
       rspec-expectations (~> 2.14.0)
       rspec-mocks (~> 2.14.0)
     rspec-core (2.14.7)
-    rspec-expectations (2.14.4)
+    rspec-expectations (2.14.5)
       diff-lcs (>= 1.1.3, < 2.0)
-    rspec-mocks (2.14.4)
+    rspec-mocks (2.14.5)
     zk (1.9.3)
       logging (~> 1.7.2)
       zookeeper (~> 1.4.0)
     zookeeper (1.4.8)
 
 PLATFORMS
-  java
   ruby
 
 DEPENDENCIES

README.md

@@ -61,6 +61,16 @@ If you set your `reporter_type` to `"zookeeper"` you should also set these param
 * `zk_hosts`: a list of the zookeeper hosts comprising the [ensemble](https://zookeeper.apache.org/doc/r3.1.2/zookeeperAdmin.html#sc_zkMulitServerSetup) that nerve will submit registration to
 * `zk_path`: the path (or [znode](https://zookeeper.apache.org/doc/r3.1.2/zookeeperProgrammers.html#sc_zkDataModel_znodes)) where the registration will be created; nerve will create the [ephemeral node](https://zookeeper.apache.org/doc/r3.1.2/zookeeperProgrammers.html#Ephemeral+Nodes) that is the registration as a child of this path
 
+#### Etcd Reporter ####
+
+Note: Etcd support is currently experimental! 
+
+If you set your `reporter_type` to `"etcd"` you should also set these parameters:
+
+* `etcd_host`: etcd host that nerve will submit registration to
+* `etcd_port`: port to connect to etcd.
+* `etcd_path`: the path where the registration will be created; nerve will create a node with a 30s ttl that is the registration as a child of this path, and then update it every few seconds
+
 ### Checks ###
 
 The core of nerve is a set of service checks.

example/nerve_services/etcd_service1.json

@@ -0,0 +1,18 @@
+{
+  "host": "1.2.3.4",
+  "port": 3000,
+  "reporter_type": "etcd",
+  "etcd_host": "localhost",
+  "etcd_port": 4001,
+  "etcd_path": "/nerve/services/your_http_service/services",
+  "check_interval": 2,
+  "checks": [
+    {
+      "type": "http",
+      "uri": "/health",
+      "timeout": 0.2,
+      "rise": 3,
+      "fall": 2
+    }
+  ]
+}

lib/nerve/reporter.rb

@@ -1,3 +1,5 @@
+require 'nerve/utils'
+require 'nerve/log'
 
 module Nerve
   class Reporter

lib/nerve/reporter/base.rb

@@ -24,6 +24,12 @@ def update_data(new_data='')
 
     def ping?
     end
+
+    protected
+    def parse_data(data)
+      return data if data.class == String
+      return data.to_json
+    end
   end
 end
 

lib/nerve/reporter/etcd.rb

@@ -0,0 +1,75 @@
+require 'nerve/reporter/base'
+require 'etcd'
+
+class Nerve::Reporter
+  class Etcd < Base
+    def initialize(service)
+      %w{etcd_host instance_id host port}.each do |required|
+        raise ArgumentError, "missing required argument #{required} for new service watcher" unless service[required]
+      end
+      @host = service['etcd_host']
+      @port = service['etcd_port'] || 4003
+      path = service['etcd_path'] || '/'
+      @key = path.split('/').push(service['instance_id']).join('/')
+      @data = parse_data({'host' => service['host'], 'port' => service['port'], 'name' => service['instance_id']})
+    end
+
+    def start()
+      log.info "nerve: waiting to connect to etcd at #{@path}"
+      @etcd = ::Etcd.client(:host => @host, :port => @port)
+      log.info "nerve: successfully created etcd connection to #{@key}"
+    end
+
+    def stop()
+       report_down
+       @etcd = nil
+    end
+
+    def report_up()
+      etcd_save
+    end
+
+    def report_down
+      etcd_delete
+    end
+
+    def update_data(new_data='')
+      @data = parse_data(new_data)
+      etcd_save
+    end
+
+    def ping?
+      if @full_key
+        etcd_save
+      else
+        @etcd.leader
+      end
+    end
+
+    private
+
+    def etcd_delete
+      return unless @etcd and @full_key
+      begin
+        @etcd.delete(@full_key)
+      rescue ::Etcd::KeyNotFound
+      rescue Errno::ECONNREFUSED
+      end
+    end
+
+    def etcd_create
+      @full_key = @etcd.create_in_order(@key, :value => @data).key
+      log.info "Created etcd node path #{@full_key}"
+    end
+
+    def etcd_save
+      return etcd_create unless @full_key
+      begin
+        @etcd.set(@key, :value => @data, ttl => 30)
+      rescue ::Etcd::KeyNotFound
+        etcd_create
+      end
+    end
+  end
+end
+

lib/nerve/reporter/zookeeper.rb

@@ -65,11 +65,6 @@ def zk_save
         zk_create
       end
     end
-
-    def parse_data(data)
-      return data if data.class == String
-      return data.to_json
-    end
   end
 end
 

lib/nerve/service_watcher/base.rb

@@ -1,3 +1,5 @@
+require 'nerve/ring_buffer'
+
 module Nerve
   module ServiceCheck
     class BaseServiceCheck

lib/nerve/service_watcher/http.rb

@@ -21,6 +21,8 @@ def initialize(opts={})
         @open_timeout = opts['open_timeout'] || 0.2
         @ssl_timeout  = opts['ssl_timeout']  || 0.2
 
+        @expect      = opts['expect']
+
         @name        = "http-#{@host}:#{@port}#{@uri}"
       end
 
@@ -30,12 +32,13 @@ def check
         connection = get_connection
         response = connection.get(@uri)
         code = response.code.to_i
+        body = response.body
 
-        if code >= 200 and code < 300
-          log.debug "nerve: check #{@name} got response code #{code} with body \"#{response.body}\""
+        if code >= 200 and code < 300 and (@expect == nil || body.include?(@expect))
+          log.debug "nerve: check #{@name} got response code #{code} with body \"#{body}\""
           return true
         else
-          log.error "nerve: check #{@name} got response code #{code} with body \"#{response.body}\""
+          log.error "nerve: check #{@name} got response code #{code} with body \"#{body}\""
           return false
         end
       end

nerve.gemspec

@@ -17,8 +17,10 @@ Gem::Specification.new do |gem|
   gem.test_files    = gem.files.grep(%r{^(test|spec|features)/})
   gem.require_paths = ["lib"]
 
+  gem.add_runtime_dependency "json"
   gem.add_runtime_dependency "zk", "~> 1.9.2"
   gem.add_runtime_dependency "bunny", "= 1.1.0"
+  gem.add_runtime_dependency "etcd", "~> 0.2.3"
 
   gem.add_development_dependency "rake"
   gem.add_development_dependency "rspec"

spec/example_services_spec.rb

@@ -0,0 +1,29 @@
+require 'json'
+require 'nerve/reporter'
+require 'nerve/service_watcher'
+
+describe "example services are valid" do
+  Dir.foreach("#{File.dirname(__FILE__)}/../example/nerve_services") do |item|
+    next if item == '.' or item == '..'
+    service_data = JSON.parse(IO.read("#{File.dirname(__FILE__)}/../example/nerve_services/#{item}"))
+    service_data['name'] = item.gsub(/\.json$/, '')
+    service_data['instance_id'] = '1'
+    context "when #{item} can be initialized as a valid reporter" do
+      reporter = nil
+      it 'Can new_from_service' do
+        expect { reporter = Nerve::Reporter.new_from_service(service_data) }.to_not raise_error()
+      end
+      it 'Created a reporter object' do
+        expect(reporter.is_a?(Nerve::Reporter::Base)).to eql(true)
+      end
+    end
+    context "when #{item} can be initialized as a valid service watcher" do
+      it do
+        watcher = nil
+        expect { watcher = Nerve::ServiceWatcher.new(service_data) }.to_not raise_error()
+        expect(watcher.is_a?(Nerve::ServiceWatcher)).to eql(true)
+      end
+    end
+  end
+end
+

spec/lib/nerve/reporter_etcd_spec.rb

@@ -0,0 +1,18 @@
+require 'spec_helper'
+require 'nerve/reporter/etcd'
+
+describe Nerve::Reporter::Etcd do
+  let(:subject) { {
+      'etcd_host' => 'etcdhost1',
+      'etcd_port' => 4001,
+      'etcd_path' => '/path',
+      'instance_id' => 'instance_id',
+      'host' => 'host',
+      'port' => 'port'
+    }
+  }
+  it 'actually constructs an instance' do
+    expect(Nerve::Reporter::Etcd.new(subject).is_a?(Nerve::Reporter::Etcd)).to eql(true)
+  end
+end
+

spec/lib/nerve/reporter_spec.rb

@@ -25,3 +25,18 @@
   end
 end
 
+class Nerve::Reporter::Test < Nerve::Reporter::Base
+end
+
+describe Nerve::Reporter::Test do
+  let(:subject) {Nerve::Reporter::Test.new({}) }
+  it 'has parse data method that passes strings' do
+    expect(subject.send(:parse_data, 'foobar')).to eql('foobar')
+  end
+  it 'jsonifies anything that is not a string' do
+    thing_to_parse = double()
+    expect(thing_to_parse).to receive(:to_json).and_return('{"some":"json"}')
+    expect(subject.send(:parse_data, thing_to_parse)).to eql('{"some":"json"}')
+  end
+end
+