display/preload the logs of the last/current operation

app/controllers/admin/backups_controller.rb

@@ -2,13 +2,14 @@ require_dependency "backup_restore"
 
 class Admin::BackupsController < Admin::AdminController
 
-  skip_before_filter :check_xhr, only: [:index, :show]
+  skip_before_filter :check_xhr, only: [:index, :show, :logs]
 
   def index
     respond_to do |format|
       format.html do
         store_preloaded("backups", MultiJson.dump(serialize_data(Backup.all, BackupSerializer)))
         store_preloaded("operations_status", MultiJson.dump(BackupRestore.operations_status))
+        store_preloaded("logs", MultiJson.dump(BackupRestore.logs))
         render "default/empty"
       end
       format.json do
@@ -55,6 +56,7 @@ class Admin::BackupsController < Admin::AdminController
 
   def logs
     store_preloaded("operations_status", MultiJson.dump(BackupRestore.operations_status))
+    store_preloaded("logs", MultiJson.dump(BackupRestore.logs))
     render "default/empty"
   end
 

lib/backup_restore.rb

@@ -7,6 +7,7 @@ module BackupRestore
 
   DUMP_FILE = "dump.sql"
   METADATA_FILE = "meta.json"
+  LOGS_CHANNEL = "/admin/backups/logs"
 
   def self.backup!(user_id, publish_to_message_bus = false)
     exporter = Export::Exporter.new(user_id, publish_to_message_bus)
@@ -32,8 +33,10 @@ module BackupRestore
   end
 
   def self.mark_as_running!
-    # TODO: should acquire a lock and raise an exception if already running!
+    # TODO: for more safety, it should acquire a lock
+    #       and raise an exception if already running!
     $redis.set(running_key, "1")
+    save_start_logs_message_id
   end
 
   def self.is_operation_running?
@@ -59,6 +62,11 @@ module BackupRestore
     }
   end
 
+  def self.logs
+    id = start_logs_message_id
+    MessageBus.backlog(LOGS_CHANNEL, id).map { |m| m.data }
+  end
+
   def self.current_version
     ActiveRecord::Migrator.current_version
   end
@@ -96,6 +104,19 @@ module BackupRestore
     $redis.del(shutdown_signal_key)
   end
 
+  def self.save_start_logs_message_id
+    id = MessageBus.last_id(LOGS_CHANNEL)
+    $redis.set(start_logs_message_id_key, id)
+  end
+
+  def self.start_logs_message_id
+    $redis.get(start_logs_message_id_key).to_i
+  end
+
+  def self.start_logs_message_id_key
+    "start_logs_message_id"
+  end
+
   def self.start!(runner)
     child = fork do
       begin

lib/export/exporter.rb

@@ -296,7 +296,7 @@ module Export
     def publish_log(message)
       return unless @publish_to_message_bus
       data = { timestamp: Time.now, operation: "backup", message: message }
-      MessageBus.publish("/admin/backups/logs", data, user_ids: [@user_id])
+      MessageBus.publish(BackupRestore::LOGS_CHANNEL, data, user_ids: [@user_id])
     end
 
   end

lib/import/importer.rb

@@ -319,7 +319,7 @@ module Import
     def publish_log(message)
       return unless @publish_to_message_bus
       data = { timestamp: Time.now, operation: "restore", message: message }
-      MessageBus.publish("/admin/backups/logs", data, user_ids: [@user_id])
+      MessageBus.publish(BackupRestore::LOGS_CHANNEL, data, user_ids: [@user_id])
     end
 
   end

spec/controllers/admin/backups_controller_spec.rb

@@ -16,13 +16,16 @@ describe Admin::BackupsController do
 
       context "html format" do
 
-        it "preloads both backups and operations_status" do
+        it "preloads important data" do
           Backup.expects(:all).returns([])
           subject.expects(:store_preloaded).with("backups", "[]")
 
           BackupRestore.expects(:operations_status).returns({})
           subject.expects(:store_preloaded).with("operations_status", "{}")
 
+          BackupRestore.expects(:logs).returns([])
+          subject.expects(:store_preloaded).with("logs", "[]")
+
           xhr :get, :index, format: :html
 
           response.should be_success
@@ -134,15 +137,17 @@ describe Admin::BackupsController do
 
     describe ".logs" do
 
-      it "preloads operations_status" do
+      it "preloads important data" do
         BackupRestore.expects(:operations_status).returns({})
         subject.expects(:store_preloaded).with("operations_status", "{}")
 
+        BackupRestore.expects(:logs).returns([])
+        subject.expects(:store_preloaded).with("logs", "[]")
+
         xhr :get, :logs, format: :html
 
         response.should be_success
       end
-
     end
 
     describe ".restore" do