Optimize timing to the schedule of workers (#17755)

manifests/check_mirrors.pp

@@ -70,8 +70,9 @@ class tails::check_mirrors (
     ],
   }
 
+  # Full run
   cron { 'tails_check_mirrors':
-    command     => "sleep \$(( \$( </dev/urandom od -N2 -t u2 -A none ) >> 5 )) && \"${repo_checkout}/check-mirrors.rb\"",
+    command     => "sleep \$(( \$( </dev/urandom od -N2 -t u2 -A none ) >> 5 )) && \"${repo_checkout}/check-mirrors.rb --ignore-failures failures.json\"",
     user        => $user,
     hour        => 0,
     minute      => 16,
@@ -89,4 +90,37 @@ class tails::check_mirrors (
     environment => [ 'TMPDIR=/tmp' ],
   }
 
+  # Fast run #1: optimized for European morning
+  cron { 'tails_check_mirrors':
+    command     => "sleep \$(( \$( </dev/urandom od -N2 -t u2 -A none ) >> 5 )) && \"${repo_checkout}/check-mirrors.rb --store-failures failures.json\"",
+    user        => $user,
+    hour        => 4,
+    minute      => 16,
+    require     => [Vcsrepo[$repo_checkout], Package[$needed_packages],
+                Postfix::Mailalias[$user], Exec['Import Tails signing key']],
+    environment => [ "TMPDIR=/tmp" ],
+  }
+
+  # Fast run #2: optimized for American morning
+  cron { 'tails_check_mirrors':
+    command     => "sleep \$(( \$( </dev/urandom od -N2 -t u2 -A none ) >> 5 )) && \"${repo_checkout}/check-mirrors.rb --store-failures failures.json\"",
+    user        => $user,
+    hour        => 12,
+    minute      => 16,
+    require     => [Vcsrepo[$repo_checkout], Package[$needed_packages],
+                Postfix::Mailalias[$user], Exec['Import Tails signing key']],
+    environment => [ "TMPDIR=/tmp" ],
+  }
+
+  # Fast run #3: to complete the 3 × 8 shifts
+  cron { 'tails_check_mirrors':
+    command     => "sleep \$(( \$( </dev/urandom od -N2 -t u2 -A none ) >> 5 )) && \"${repo_checkout}/check-mirrors.rb --store-failures failures.json\"",
+    user        => $user,
+    hour        => 20,
+    minute      => 16,
+    require     => [Vcsrepo[$repo_checkout], Package[$needed_packages],
+                Postfix::Mailalias[$user], Exec['Import Tails signing key']],
+    environment => [ "TMPDIR=/tmp" ],
+  }
+
 }