[#67233096] Move cron.daily to 05:**

Splay `cron.daily` - the most intensive one which handles backups,
logrotate, rkhunter, etc - across an entire hour at 5AM. The
hourly/weekly/monthly barely do anything so I'm leaving those be.

We did splay this before. But only to 15mins which doesn't give us much room
across 40~ nodes. I'm picking 5AM not necessarily to avoid clashing with IDA
and HMRC, but just so that we have an entire hour to choose from.

This is in order to reduce our concurrent disk IO across all machines. It is
partly by request of Skyscape, who appear to be struggling now that they
have many tenants running Ubuntu which all kick off `cron.daily` at roughly
the same time. But it is beneficial for us regardless of what vendor we are
on.

modules/cron/manifests/init.pp

@@ -19,10 +19,10 @@
   # set the timings of the scheduled tasks at different times
   # for each machine, but at predicable times for the various
   # schedules. See spec tests for what ranges these equate to.
-  $hourly_time  = fqdn_rand(15) + 1
-  $daily_time   = $hourly_time + 10
-  $weekly_time  = $hourly_time + 25
-  $monthly_time = $hourly_time + 40
+  $hourly_min  = fqdn_rand(15) + 1
+  $daily_min   = fqdn_rand(59)
+  $weekly_min  = $hourly_min + 25
+  $monthly_min = $hourly_min + 40
   file {'/etc/crontab':
     ensure  => present,
     owner   => 'root',

modules/cron/spec/classes/cron_spec.rb

@@ -4,8 +4,8 @@
   it 'should set cron.hourly to **:01-**:15' do
     should contain_file('/etc/crontab').with_content(/^([1-9]|1[0-5])\s+\*\s+.*cron\.hourly$/)
   end
-  it 'should set cron.daily to 06:11-06:25' do
-    should contain_file('/etc/crontab').with_content(/^(1[1-9]|2[0-5])\s+6\s+.*cron\.daily \)$/)
+  it 'should set cron.daily to 05:01-05:59' do
+    should contain_file('/etc/crontab').with_content(/^([0-9]|[1-5][0-9])\s+5\s+.*cron\.daily \)$/)
   end
   it 'should set cron.weekly to 06:26-06:40' do
     should contain_file('/etc/crontab').with_content(/^(2[6-9]|3[0-9]|40)\s+6\s+.*cron\.weekly \)$/)

modules/cron/templates/etc/crontab.erb

@@ -8,8 +8,8 @@ SHELL=/bin/sh
 PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
 
 # m h dom mon dow user  command
-<%= @hourly_time %> *    * * *   root    cd / && run-parts --report /etc/cron.hourly
-<%= @daily_time %> 6    * * *   root    test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily )
-<%= @weekly_time %> 6    * * 7   root    test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.weekly )
-<%= @monthly_time %> 6    1 * *   root    test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.monthly )
+<%= @hourly_min %> *    * * *   root    cd / && run-parts --report /etc/cron.hourly
+<%= @daily_min %> 5    * * *   root    test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily )
+<%= @weekly_min %> 6    * * 7   root    test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.weekly )
+<%= @monthly_min %> 6    1 * *   root    test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.monthly )
 #