Drop hard-coded log_file

Because the service config file is shared among multiple services,
we should not set the option without any specific reason. In case
the option is not set (and no --log-file argument is passed) then
log file name is determined according to the process name, and each
service creates its own file.

Change-Id: I65b1abc96be4503d51d8b1af2c4ece7aa52be563

manifests/logging.pp

@@ -35,7 +35,7 @@
 #
 # [*log_file*]
 #   (Optional) File where logs should be stored.
-#   Defaults to '/var/log/watcher/watcher.log'
+#   Defaults to $facts['os_service_default']
 #
 # [*logging_context_format_string*]
 #   (Optional) Format string to use for log messages with context.
@@ -114,7 +114,7 @@ class watcher::logging(
   $use_stderr                    = $facts['os_service_default'],
   $syslog_log_facility           = $facts['os_service_default'],
   $log_dir                       = '/var/log/watcher',
-  $log_file                      = '/var/log/watcher/watcher.log',
+  $log_file                      = $facts['os_service_default'],
   $debug                         = $facts['os_service_default'],
   $logging_context_format_string = $facts['os_service_default'],
   $logging_default_format_string = $facts['os_service_default'],

releasenotes/notes/drop-hardcoded-log_file-3f656a530073379f.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    The ``watcher::logging::log_file`` now defaults to the os_service_default
+    fact so that log file name is determined automatically accoridng to
+    the process names.

spec/classes/watcher_logging_spec.rb

@@ -66,7 +66,7 @@ describe 'watcher::logging' do
         :use_stderr          => '<SERVICE DEFAULT>',
         :syslog_log_facility => '<SERVICE DEFAULT>',
         :log_dir             => '/var/log/watcher',
-        :log_file            => '/var/log/watcher/watcher.log',
+        :log_file            => '<SERVICE DEFAULT>',
         :debug               => '<SERVICE DEFAULT>',
       )
     end