Support redis sentinels and add master property

lib/puppet/provider/sensu_redis_config/json.rb

@@ -16,6 +16,14 @@ def conf
   end
 
   def flush
+    # Clean nil valued properties, esp. sentinel related
+    # Related to https://github.com/sensu/sensu-puppet/issues/394.
+    self.class.resource_type.validproperties.each do |prop|
+      if resource.should(prop).nil?
+        conf['redis'].delete prop.to_s
+      end
+    end
+
     File.open(config_file, 'w') do |f|
       f.puts JSON.pretty_generate(conf)
     end
@@ -38,19 +46,27 @@ def exists?
   end
 
   def port
-    conf['redis']['port'].to_s
+    if conf['redis']['port'] then conf['redis']['port'].to_s else :absent end
   end
 
   def port=(value)
-    conf['redis']['port'] = value.to_i
+    if value == :absent
+      conf['redis'].delete 'port'
+    else
+      conf['redis']['port'] = value.to_i
+    end
   end
 
   def host
-    conf['redis']['host']
+    conf['redis']['host'] || :absent
   end
 
   def host=(value)
-    conf['redis']['host'] = value
+    if value == :absent
+      conf['redis'].delete 'host'
+    else
+      conf['redis']['host'] = value
+    end
   end
 
   def password
@@ -77,6 +93,30 @@ def db=(value)
     conf['redis']['db'] = value.to_i
   end
 
+  def sentinels
+    conf['redis']['sentinels'] || []
+  end
+
+  def sentinels=(value)
+    if value == []
+      conf['redis'].delete 'sentinels'
+    else
+      conf['redis']['sentinels'] = value
+    end
+  end
+
+  def master
+    conf['redis']['master'] || :absent
+  end
+
+  def master=(value)
+    if value == :absent
+      conf['redis'].delete 'master'
+    else
+      conf['redis']['master'] = value.to_s
+    end
+  end
+
   def auto_reconnect
     conf['redis']['auto_reconnect']
   end

lib/puppet/type/sensu_redis_config.rb

@@ -1,3 +1,4 @@
+require 'set'
 require File.expand_path(File.join(File.dirname(__FILE__), '..', '..',
                                    'puppet_x', 'sensu', 'boolean_property.rb'))
 
@@ -13,6 +14,22 @@ def initialize(*args)
     ].select { |ref| catalog.resource(ref) }
   end
 
+  def has_sentinels?
+    sentinels = self.should(:sentinels)
+    return sentinels && !sentinels.empty?
+  end
+
+  def pre_run_check
+    if self.has_sentinels? then
+      if self.should(:host) && self.should(:host) != :absent then
+        raise Puppet::Error, "Redis 'host' (#{self.should(:host)}) must not be specified when sentinels are specified"
+      end
+      if self.should(:port) && self.should(:port) != :absent then
+        raise Puppet::Error, "Redis 'port' (#{self.should(:port)}) must not be specified when sentinels are specified"
+      end
+    end
+  end
+
   ensurable do
     newvalue(:present) do
       provider.create
@@ -37,13 +54,25 @@ def initialize(*args)
   newproperty(:port) do
     desc "The port that Redis is listening on"
 
-    defaultto '6379'
+    defaultto {
+      if [email protected]_sentinels? then '6379' else :absent end
+    }
+    def insync?(is)
+      if should.is_a?(Symbol) then should == is else super(is) end
+    end
   end
 
   newproperty(:host) do
     desc "The hostname that Redis is listening on"
 
-    defaultto '127.0.0.1'
+    defaultto {
+      # Use absent to ensure that config is flushed
+      # when property gets unset
+      if [email protected]_sentinels? then '127.0.0.1' else :absent end
+    }
+    def insync?(is)
+      if should.is_a?(Symbol) then should == is else super(is) end
+    end
   end
 
   newproperty(:password) do
@@ -68,6 +97,33 @@ def initialize(*args)
     defaultto :true
   end
 
+  newproperty(:sentinels, :array_matching => :all) do
+    desc "Redis Sentinel configuration for HA clustering"
+    defaultto []
+
+    def insync?(is)
+      # this probably needs more checks, for duplicate values, etc
+      # but for now it works fine
+      Set.new(is) == Set.new(should)
+    end
+
+    munge do |value|
+      Hash[value.map do |k, v|
+        [k, if k == "port" then v.to_i else v.to_s end]
+      end]
+    end
+  end
+
+  newproperty(:master) do
+    desc "Redis master name in the sentinel configuration"
+    # Use absent to ensure that config is flushed
+    # when property gets unset
+    defaultto :absent
+    def insync?(is)
+      if should.is_a?(Symbol) then should == is else super(is) end
+    end
+  end
+
   autorequire(:package) do
     ['sensu']
   end

manifests/init.pp

@@ -173,6 +173,14 @@
 #   Integer.  The Redis instance DB to use/select
 #   Default: 0
 #
+# [*redis_sentinels*]
+#   Array. Redis Sentinel configuration and connection information for one or more Sentinels
+#   Default: Not configured
+#
+# [*redis_master*]
+#   String. Redis master name in the sentinel configuration
+#   Default: undef. In the end whatever sensu defaults to, which is "mymaster" currently.
+#
 # [*redis_auto_reconnect*]
 #   Boolean.  Reconnect to Redis in the event of a connection failure
 #   Default: true
@@ -354,6 +362,8 @@
   $redis_reconnect_on_error       = false,
   $redis_db                       = 0,
   $redis_auto_reconnect           = true,
+  $redis_sentinels                = undef,
+  $redis_master                   = undef,
   $api_bind                       = '0.0.0.0',
   $api_host                       = '127.0.0.1',
   $api_port                       = 4567,

manifests/redis/config.pp

@@ -23,15 +23,23 @@
     before => Sensu_redis_config[$::fqdn],
   }
 
+  $has_sentinels = !($sensu::redis_sentinels == undef or $sensu::redis_sentinels == [])
+  $host = $has_sentinels ? { false => $sensu::redis_host, true  => undef, }
+  $port = $has_sentinels ? { false => $sensu::redis_port, true  => undef, }
+  $sentinels = $has_sentinels ? { true  => $sensu::redis_sentinels, false => undef, }
+  $master = $has_sentinels ? { true => $sensu::redis_master, false => undef, }
+
   sensu_redis_config { $::fqdn:
     ensure             => $ensure,
     base_path          => "${sensu::etc_dir}/conf.d",
-    host               => $sensu::redis_host,
-    port               => $sensu::redis_port,
+    host               => $host,
+    port               => $port,
     password           => $sensu::redis_password,
     reconnect_on_error => $sensu::redis_reconnect_on_error,
     db                 => $sensu::redis_db,
     auto_reconnect     => $sensu::redis_auto_reconnect,
+    sentinels          => $sentinels,
+    master             => $master,
   }
 
 }

spec/classes/sensu_redis_spec.rb

@@ -14,7 +14,7 @@
       )}
     end # default settings
 
-    context 'be configurable' do
+    context 'be configurable without sentinels' do
       let(:params) { {
         :redis_host           => 'redis.domain.com',
         :redis_port           => 1234,
@@ -28,9 +28,43 @@
         :port           => 1234,
         :password       => 'password',
         :db             => 1,
-        :auto_reconnect => false        
+        :auto_reconnect => false,
+        :sentinels      => nil,
+        :master         => nil
       )}
-    end # be configurable
+    end # be configurable without sentinels
+
+    context 'be configurable with sentinels' do
+      let(:params) { {
+        :redis_password       => 'password',
+        :redis_db             => 1,
+        :redis_auto_reconnect => false,
+        :redis_sentinels      => [{
+            'host' => 'redis1.domain.com',
+            'port' => 1234
+        }, {
+            'host' => 'redis2.domain.com',
+            'port' => '5678'
+        }],
+        :redis_master         => 'master-name'
+      } }
+
+      it { should contain_sensu_redis_config('testhost.domain.com').with(
+        :host           => nil,
+        :port           => nil,
+        :password       => 'password',
+        :db             => 1,
+        :auto_reconnect => false,
+        :sentinels      => [{
+            'host' => 'redis1.domain.com',
+            'port' => 1234
+        }, {
+            'host'  => 'redis2.domain.com',
+            'port'  => 5678
+        }],
+        :master         => "master-name"
+      )}
+    end # be configurable with sentinels
 
     context 'with server' do
       let(:params) { { :server => true } }