Merge branch '24059-round-robin-repository-storage' into 'master'

Resolve "Introduce round-robin project creation to spread load over multiple shards"

Allow multiple shards to be enabled in the admin settings page, balancing project creation across all enabled shards.

* `f.select ..., multiple: true` isn't the most beautiful UI in the world, but switching to `collection_check_boxes` (or a facsimile thereof) isn't trivial
* Should `pick_repository_storage` be a method of `ApplicationSetting`, or `Project`? It's going to accrete logic over time so perhaps it should be its own class already?
* This is written to avoid the need for a database migration, so it is`serialize :repository_storage` without `, Array`. This is tested, but alternatives include:
  * Add a database migration
  * Write a custom Coder that will accept a String or Array in `load` and always `dump an Array.

Closes #24059

See merge request !7273

Signed-off-by: Rémy Coutable <remy@rymai.me>

2 files changed, 31 insertions, 2 deletions

diff --git a/db/migrate/20161103171205_rename_repository_storage_column.rb b/db/migrate/20161103171205_rename_repository_storage_column.rb
new file mode 100644
index 00000000000..e9f992793b4
--- /dev/null
+++ b/db/migrate/20161103171205_rename_repository_storage_column.rb
@@ -0,0 +1,29 @@
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class RenameRepositoryStorageColumn < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+
+  # When a migration requires downtime you **must** uncomment the following
+  # constant and define a short and easy to understand explanation as to why the
+  # migration requires downtime.
+  # DOWNTIME_REASON = ''
+
+  # When using the methods "add_concurrent_index" or "add_column_with_default"
+  # you must disable the use of transactions as these methods can not run in an
+  # existing transaction. When using "add_concurrent_index" make sure that this
+  # method is the _only_ method called in the migration, any other changes
+  # should go in a separate migration. This ensures that upon failure _only_ the
+  # index creation fails and can be retried or reverted easily.
+  #
+  # To disable transactions uncomment the following line and remove these
+  # comments:
+  # disable_ddl_transaction!
+
+  def change
+    rename_column :application_settings, :repository_storage, :repository_storages
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 02282b0f666..a5f5f812f0d 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20161024042317) do
+ActiveRecord::Schema.define(version: 20161103171205) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -88,7 +88,7 @@ ActiveRecord::Schema.define(version: 20161024042317) do
     t.integer "container_registry_token_expire_delay", default: 5
     t.text "after_sign_up_text"
     t.boolean "user_default_external", default: false, null: false
-    t.string "repository_storage", default: "default"
+    t.string "repository_storages", default: "default"
     t.string "enabled_git_access_protocol"
     t.boolean "domain_blacklist_enabled", default: false
     t.text "domain_blacklist"