Add support for oom_score_adj

Author: jlutran

manifests/config.pp

@@ -81,6 +81,7 @@
   $auth_backends                       = $rabbitmq::auth_backends
   $cluster_partition_handling          = $rabbitmq::cluster_partition_handling
   $file_limit                          = $rabbitmq::file_limit
+  $oom_score_adj                       = $rabbitmq::oom_score_adj
   $collect_statistics_interval         = $rabbitmq::collect_statistics_interval
   $ipv6                                = $rabbitmq::ipv6
   $inetrc_config                       = $rabbitmq::inetrc_config
@@ -235,7 +236,10 @@
   if $facts['systemd'] { # systemd fact provided by systemd module
     systemd::service_limits { "${service_name}.service":
       selinux_ignore_defaults => ($facts['os']['family'] == 'RedHat'),
-      limits                  => { 'LimitNOFILE' => $file_limit },
+      limits                  => {
+        'LimitNOFILE'    => $file_limit,
+        'OOMScoreAdjust' => $oom_score_adj,
+      },
       # The service will be notified when config changes
       restart_service         => false,
     }

manifests/init.pp

@@ -140,6 +140,8 @@
 #   to 'False' and set 'erlang_cookie'.
 # @param file_limit
 #   Set rabbitmq file ulimit. Defaults to 16384. Only available on systems with `$::osfamily == 'Debian'` or `$::osfamily == 'RedHat'`.
+# @param oom_score_adj
+#   Set rabbitmq-server process OOM score. Defaults to 0.
 # @param heartbeat
 #   Set the heartbeat timeout interval, default is unset which uses the builtin server defaults of 60 seconds. Setting this
 # @param inetrc_config
@@ -394,6 +396,7 @@
   Boolean $wipe_db_on_cookie_change                                                                = false,
   String $cluster_partition_handling                                                               = 'ignore',
   Variant[Integer[-1],Enum['unlimited'],Pattern[/^(infinity|\d+(:(infinity|\d+))?)$/]] $file_limit = 16384,
+  Optional[Integer[-1000, 1000]] $oom_score_adj                                                    = 0,
   Hash $environment_variables                                                                      = { 'LC_ALL' => 'en_US.UTF-8' },
   Hash $config_variables                                                                           = {},
   Hash $config_kernel_variables                                                                    = {},

spec/classes/rabbitmq_spec.rb

@@ -170,6 +170,51 @@
         end
       end
 
+      [-1000, 0, 1000].each do |value|
+        context "with oom_score_adj => '#{value}'" do
+          let(:params) { { oom_score_adj: value } }
+
+          if facts[:os]['family'] == 'RedHat'
+            it do
+              is_expected.to contain_file('/etc/systemd/system/rabbitmq-server.service.d/limits.conf').
+                with_owner('0').
+                with_group('0').
+                with_mode('0644').
+                that_notifies('Class[Rabbitmq::Service]').
+                with_content("OOMScoreAdjust=#{value}\n")
+            end
+          else
+            it { is_expected.not_to contain_file('/etc/security/limits.d/rabbitmq-server.conf') }
+          end
+
+          if facts[:os]['family'] == 'Debian'
+            it { is_expected.to contain_file('/etc/default/rabbitmq-server').with_content(/^echo #{value} > \/proc\/\$\$\/oom_score_adj$/) }
+          else
+            it { is_expected.not_to contain_file('/etc/default/rabbitmq-server') }
+          end
+
+          if facts[:systemd]
+            it do
+              is_expected.to contain_systemd__service_limits("#{name}.service").
+                with_limits('OOMScoreAdjust' => value).
+                with_restart_service(false)
+            end
+          else
+            it { is_expected.not_to contain_systemd__service_limits("#{name}.service") }
+          end
+        end
+      end
+
+      [-2000, 2000, '500', 'foo'].each do |value|
+        context "with oom_score_adj => '#{value}'" do
+          let(:params) { { oom_score_adj: value } }
+
+          it 'does not compile' do
+            expect { catalogue }.to raise_error(Puppet::PreformattedError, %r{Error while evaluating a Resource Statement})
+          end
+        end
+      end
+
       context 'on systems with systemd', if: facts[:systemd] do
         it do
           is_expected.to contain_systemd__service_limits("#{name}.service").

templates/default.erb

@@ -8,3 +8,7 @@
 # to handle many simultaneous connections. Refer to the system
 # documentation for ulimit (in man bash) for more information.
 ulimit -n <%= @file_limit %>
+
+# OOM score. It sets the score of the init script, but as this value is
+# inherited, it also applies to the rabbitmq-server.
+echo <%= @oom_score_adj %> > /proc/$$/oom_score_adj