in_syslog: Replace priority_key with proper severity_key

lib/fluent/plugin/in_syslog.rb

@@ -56,7 +56,7 @@ class SyslogInput < Input
       23  => 'local7'
     }
 
-    PRIORITY_MAP = {
+    SEVERITY_MAP = {
       0  => 'emerg',
       1  => 'alert',
       2  => 'crit',
@@ -91,8 +91,8 @@ class SyslogInput < Input
     config_param :resolve_hostname, :bool, default: nil
     desc 'The field name of source address of sender.'
     config_param :source_address_key, :string, default: nil
-    desc 'The field name of the priority.'
-    config_param :priority_key, :string, default: nil
+    desc 'The field name of the severity.'
+    config_param :severity_key, :string, default: nil, alias: :priority_key
     desc 'The field name of the facility.'
     config_param :facility_key, :string, default: nil
 
@@ -119,6 +119,10 @@ def configure(conf)
 
       super
 
+      if conf.has_key?('priority_key')
+        log.warn "priority_key is deprecated. Use severity_key instead"
+      end
+
       @use_default = false
 
       @parser = parser_create
@@ -233,14 +237,14 @@ def message_handler(data, sock)
 
         pri ||= record.delete('pri')
         facility = FACILITY_MAP[pri >> 3]
-        priority = PRIORITY_MAP[pri & 0b111]
+        severity = SEVERITY_MAP[pri & 0b111]
 
-        record[@priority_key] = priority if @priority_key
+        record[@severity_key] = severity if @severity_key
         record[@facility_key] = facility if @facility_key
         record[@source_address_key] = sock.remote_addr if @source_address_key
         record[@source_hostname_key] = sock.remote_host if @source_hostname_key
 
-        tag = "#{@tag}.#{facility}.#{priority}"
+        tag = "#{@tag}.#{facility}.#{severity}"
         emit(tag, time, record)
       end
     rescue => e

test/plugin/test_in_syslog.rb

@@ -217,11 +217,15 @@ def test_msg_size_with_include_source_host
     compare_test_result(d.events, tests, {host: host})
   end
 
-  def test_msg_size_with_priority_key
-    d = create_driver([CONFIG, 'priority_key priority'].join("\n"))
+  data(
+    severity_key: 'severity_key',
+    priority_key: 'priority_key',
+  )
+  def test_msg_size_with_severity_key(param_name)
+    d = create_driver([CONFIG, "#{param_name} severity"].join("\n"))
     tests = create_test_case
 
-    priority = 'info'
+    severity = 'info'
     d.run(expect_emits: 2) do
       u = UDPSocket.new
       u.connect('127.0.0.1', PORT)
@@ -231,7 +235,7 @@ def test_msg_size_with_priority_key
     end
 
     assert(d.events.size > 0)
-    compare_test_result(d.events, tests, {priority: priority})
+    compare_test_result(d.events, tests, {severity: severity})
   end
 
   def test_msg_size_with_facility_key
@@ -311,7 +315,7 @@ def compare_test_result(events, tests, options = {})
       assert_equal(options[:host], events[i][2]['source_host']) if options[:host]
       assert_equal(options[:address], events[i][2]['source_address']) if options[:address]
       assert_equal(options[:hostname], events[i][2]['source_hostname']) if options[:hostname]
-      assert_equal(options[:priority], events[i][2]['priority']) if options[:priority]
+      assert_equal(options[:severity], events[i][2]['severity']) if options[:severity]
       assert_equal(options[:facility], events[i][2]['facility']) if options[:facility]
     }
   end