DRY up the data sync start/end times

These values are beginning to leak into multiple places. It is good
maintenance practice to try to keep them in one place.

There is probably a cleaner way of doing this with YML config, but
given that some places need the start/end times and others need
specifically the start/end hour and minute, a function seems a
reasonable thing to create to encapsulate all that knowledge.

In any case, it is an improvement on trying to duplicate the
values throughout the repository.

modules/govuk/lib/puppet/parser/functions/data_sync_times.rb

@@ -0,0 +1,38 @@
+module Puppet::Parser::Functions
+  newfunction(:format_data_sync_time, :type => :rvalue, :doc => <<-EOS
+Return information about the data sync times, depending on the argument passed
+    EOS
+  ) do |args|
+    start_hour = 22
+    start_minute = 0
+    finish_hour = 8
+    finish_minute = 0
+
+    if args.size != 1
+      raise ArgumentError, "format_data_sync_time: Wrong number of arguments " +
+      "(given #{args.size})"
+    end
+
+    type = args[0]
+
+    case type
+    when 'time_range'
+      "#{start_hour}:#{start_minute}-#{finish_hour}:#{finish_minute}"
+    when 'start_time'
+      "#{start_hour}:#{start_minute}"
+    when 'start_hour'
+      start_hour
+    when 'start_minute'
+      start_minute
+    when 'finish_time'
+      "#{finish_hour}:#{finish_minute}"
+    when 'finish_hour'
+      finish_hour
+    when 'finish_minute'
+      finish_minute
+    else
+      raise ArgumentError, "format_data_sync_time: Unknown argument #{type}"
+    end
+  end
+end
+

modules/govuk/manifests/deploy/config.pp

@@ -129,7 +129,7 @@
 
   if $::aws_migration and ($::aws_environment != 'production') {
     govuk_envvar {
-      'GOVUK_DATA_SYNC_PERIOD': value => '22:00-8:00'; # This should match up with the govuk_data_sync_in_progress class
+      'GOVUK_DATA_SYNC_PERIOD': value => format_data_sync_time('time_range');
     }
   }
 

modules/govuk_data_sync_in_progress/manifests/init.pp

@@ -17,12 +17,6 @@
 ) {
   $fact_path = '/etc/govuk/env.d/FACTER_data_sync_in_progress'
 
-  $start_hour = 22
-  $start_minute = 0
-
-  $finish_hour = 8
-  $finish_minute = 00
-
   if !defined(File[$fact_path]) {
     file { $fact_path:
       ensure  => present,
@@ -35,35 +29,35 @@
     cron { 'data_sync_started':
       command => "echo 'true' > ${fact_path}",
       user    => 'deploy',
-      hour    => $start_hour,
-      minute  => $start_minute,
+      hour    => format_data_sync_time('start_hour'),
+      minute  => format_data_sync_time('start_minute'),
     }
   }
 
   if !defined(Cron['data_sync_finished']) {
     cron { 'data_sync_finished':
       command => "echo '' > ${$fact_path}",
       user    => 'deploy',
-      hour    => $finish_hour,
-      minute  => $finish_minute,
+      hour    => format_data_sync_time('finish_hour'),
+      minute  => format_data_sync_time('finish_minute'),
     }
   }
 
   if $start_command {
     cron { "data_sync_started_${title}":
       command => $start_command,
       user    => 'deploy',
-      hour    => $start_hour,
-      minute  => $start_minute,
+      hour    => format_data_sync_time('start_hour'),
+      minute  => format_data_sync_time('start_minute'),
     }
   }
 
   if $finish_command {
     cron { "data_sync_finished_${title}":
       command => $finish_command,
       user    => 'deploy',
-      hour    => $finish_hour,
-      minute  => $finish_minute,
+      hour    => format_data_sync_time('finish_hour'),
+      minute  => format_data_sync_time('finish_minute'),
     }
   }
 }

modules/monitoring/manifests/contacts.pp

@@ -54,9 +54,8 @@
   $midday = '11:00'
   $office_day_end = '16:30'
   $midnight_day_end = '24:00'
-  # This should match up with the govuk_data_sync_in_progress class
-  $data_sync_start = '22:00'
-  $data_sync_end = '08:00'
+  $data_sync_start = format_data_sync_time('start_time')
+  $data_sync_end = format_data_sync_time('finish_time')
 
   $all_day = "${midnight_day_start}-${midnight_day_end}"
   $office_day = "${office_day_start}-${office_day_end}"