1 files changed, 63 insertions, 0 deletions
diff --git a/db/migrate/20161024042317_migrate_mailroom_queue_from_default.rb b/db/migrate/20161024042317_migrate_mailroom_queue_from_default.rb
new file mode 100644
index 00000000000..06d07bdb835
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+++ b/db/migrate/20161024042317_migrate_mailroom_queue_from_default.rb
@@ -0,0 +1,63 @@
+require 'json'
+
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class MigrateMailroomQueueFromDefault < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = true
+
+  DOWNTIME_REASON = <<-EOF
+  Moving Sidekiq jobs from queues requires Sidekiq to be stopped. Not stopping
+  Sidekiq will result in the loss of jobs that are scheduled after this
+  migration completes.
+  EOF
+
+  disable_ddl_transaction!
+
+  # Jobs for which the queue names have been changed (e.g. multiple workers
+  # using the same non-default queue).
+  #
+  # The keys are the old queue names, the values the jobs to move and their new
+  # queue names.
+  RENAMED_QUEUES = {
+      incoming_email: {
+          'EmailReceiverWorker' => :email_receiver
+      }
+  }
+
+  def up
+    Sidekiq.redis do |redis|
+      RENAMED_QUEUES.each do |queue, jobs|
+        migrate_from_queue(redis, queue, jobs)
+      end
+    end
+  end
+
+  def down
+    Sidekiq.redis do |redis|
+      RENAMED_QUEUES.each do |dest_queue, jobs|
+        jobs.each do |worker, from_queue|
+          migrate_from_queue(redis, from_queue, worker => dest_queue)
+        end
+      end
+    end
+  end
+
+  def migrate_from_queue(redis, queue, job_mapping)
+    while job = redis.lpop("queue:#{queue}")
+      payload = JSON.load(job)
+      new_queue = job_mapping[payload['class']]
+
+      # If we have no target queue to migrate to we're probably dealing with
+      # some ancient job for which the worker no longer exists. In that case
+      # there's no sane option we can take, other than just dropping the job.
+      next unless new_queue
+
+      payload['queue'] = new_queue
+
+      redis.lpush("queue:#{new_queue}", JSON.dump(payload))
+    end
+  end
+end