Logger fix (#8)

Extract the logger_patch and apply with prepend

Author: edhzsz

Gemfile.lock

@@ -1,18 +1,32 @@
 PATH
   remote: .
   specs:
-    aws_lambda_ric (1.0.0)
+    aws_lambda_ric (1.0.1)
 
 GEM
   remote: https://rubygems.org/
   specs:
+    activesupport (6.0.3.4)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 0.7, < 2)
+      minitest (~> 5.1)
+      tzinfo (~> 1.1)
+      zeitwerk (~> 2.2, >= 2.2.2)
+    concurrent-ruby (1.1.7)
+    i18n (1.8.5)
+      concurrent-ruby (~> 1.0)
     minitest (5.14.2)
     rake (13.0.1)
+    thread_safe (0.3.6)
+    tzinfo (1.2.8)
+      thread_safe (~> 0.1)
+    zeitwerk (2.4.2)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
+  activesupport (~> 6.0.1)
   aws_lambda_ric!
   bundler (>= 2.0)
   minitest (~> 5.0)

lib/aws_lambda_ric.rb

@@ -8,6 +8,7 @@
 require_relative 'aws_lambda_ric/lambda_context'
 require_relative 'aws_lambda_ric/lambda_logger'
 require_relative 'aws_lambda_ric/lambda_log_formatter'
+require_relative 'aws_lambda_ric/logger_patch'
 require_relative 'aws_lambda_ric/telemetry_log_sink'
 require_relative 'aws_lambda_ric/aws_lambda_marshaller'
 require_relative 'aws_lambda_ric/xray_cause'
@@ -149,23 +150,7 @@ def initialize(telemetry_log_fd, path_to_fd='/proc/self/fd/')
 
     def mutate_std_logger
       Logger.class_eval do
-        alias_method :orig_initialize, :initialize
-        def initialize(logdev, shift_age = 0, shift_size = 1048576, level: 'debug',
-                       progname: nil, formatter: nil, datetime_format: nil,
-                       binmode: false, shift_period_suffix: '%Y%m%d')
-          #  use unpatched constructor if logdev is a filename or an IO Object other than $stdout or $stderr
-          if logdev && logdev != $stdout && logdev != $stderr
-            orig_initialize(logdev, shift_age, shift_size, level, progname,
-                            formatter, datetime_format, binmode, shift_period_suffix)
-          else
-            self.level = level
-            self.progname = progname
-            @default_formatter = LambdaLogFormatter.new
-            self.datetime_format = datetime_format
-            self.formatter = formatter
-            @logdev = AwsLambdaRuntimeInterfaceClient::TelemetryLoggingHelper.telemetry_log_sink
-          end
-        end
+        prepend LoggerPatch
       end
     end
 

lib/aws_lambda_ric/logger_patch.rb

@@ -0,0 +1,21 @@
+# Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+
+module LoggerPatch
+  def initialize(logdev, shift_age = 0, shift_size = 1048576, level: 'debug',
+                 progname: nil, formatter: nil, datetime_format: nil,
+                 binmode: false, shift_period_suffix: '%Y%m%d')
+    #  use unpatched constructor if logdev is a filename or an IO Object other than $stdout or $stderr
+    if logdev && logdev != $stdout && logdev != $stderr
+      super(logdev, shift_age, shift_size, level: level, progname: progname,
+                      formatter: formatter, datetime_format: datetime_format,
+                      binmode: binmode, shift_period_suffix: shift_period_suffix)
+    else
+      self.level = level
+      self.progname = progname
+      @default_formatter = LambdaLogFormatter.new
+      self.datetime_format = datetime_format
+      self.formatter = formatter
+      @logdev = AwsLambdaRuntimeInterfaceClient::TelemetryLoggingHelper.telemetry_log_sink
+    end
+  end
+end

test/unit/harness-suite.json

@@ -205,6 +205,23 @@
           "response": true
         }
     },
+    {
+      "name": "test_logger_logs_to_a_file_when_logdev_is_a_file",
+      "handler": "log.log_to_file_and_read_back",
+      "environmentVariables": {
+        "_LAMBDA_TELEMETRY_LOG_FD": "test/unit/resources/fd/test_fd"
+      },
+      "request": {
+        "messages": ["Single frame written to a file\n even if there are multiple lines\nthird line"],
+        "fd_path": "test/unit/resources/fd/test_fd",
+        "file_path": "test/unit/resources/fd/test_file.txt"
+      },
+      "assertion":
+        {
+          "transform": "I, \\[[0-9]{4}-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])T(2[0-3]|[01][0-9]):[0-5][0-9]:[0-9]{2}.[0-9]{6} #[0-9]*\\]  INFO -- : Single frame written to a file\\\\n even if there are multiple lines\\\\nthird line",
+          "response": true
+        }
+    },
     {
       "name": "test_logger_uses_telemetry_log_fd_when_logdev_is_stderr",
       "handler": "log.log_to_stderr_and_read_fd",

test/unit/resources/runtime_handlers/log.rb

@@ -30,6 +30,17 @@ def log_to_stderr_and_read_fd(event:, context:)
   read_fd('', event)
 end
 
+def log_to_file_and_read_back(event:, context:)
+  logger = Logger.new(event['file_path'])
+  event['messages'].each { |m| logger.info(m) }
+  read_file('', event)
+end
+
+def read_file(content, event)
+  File.foreach(event['file_path']) { |line| content << line }
+  content
+end
+
 def read_fd(content, event)
   File.open(event['fd_path'], 'rb') do |file|
     until file.eof?