1 files changed, 231 insertions, 0 deletions
diff --git a/db/migrate/20170316163800_rename_system_namespaces.rb b/db/migrate/20170316163800_rename_system_namespaces.rb
new file mode 100644
index 00000000000..9e9fb5ac225
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+++ b/db/migrate/20170316163800_rename_system_namespaces.rb
@@ -0,0 +1,231 @@
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+class RenameSystemNamespaces < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+  include Gitlab::ShellAdapter
+  disable_ddl_transaction!
+
+  class User < ActiveRecord::Base
+    self.table_name = 'users'
+  end
+
+  class Namespace < ActiveRecord::Base
+    self.table_name = 'namespaces'
+    belongs_to :parent, class_name: 'RenameSystemNamespaces::Namespace'
+    has_one :route, as: :source
+    has_many :children, class_name: 'RenameSystemNamespaces::Namespace', foreign_key: :parent_id
+    belongs_to :owner, class_name: 'RenameSystemNamespaces::User'
+
+    # Overridden to have the correct `source_type` for the `route` relation
+    def self.name
+      'Namespace'
+    end
+
+    def full_path
+      if route && route.path.present?
+        @full_path ||= route.path
+      else
+        update_route if persisted?
+
+        build_full_path
+      end
+    end
+
+    def build_full_path
+      if parent && path
+        parent.full_path + '/' + path
+      else
+        path
+      end
+    end
+
+    def update_route
+      prepare_route
+      route.save
+    end
+
+    def prepare_route
+      route || build_route(source: self)
+      route.path = build_full_path
+      route.name = build_full_name
+      @full_path = nil
+      @full_name = nil
+    end
+
+    def build_full_name
+      if parent && name
+        parent.human_name + ' / ' + name
+      else
+        name
+      end
+    end
+
+    def human_name
+      owner&.name
+    end
+  end
+
+  class Route < ActiveRecord::Base
+    self.table_name = 'routes'
+    belongs_to :source, polymorphic: true
+  end
+
+  class Project < ActiveRecord::Base
+    self.table_name = 'projects'
+
+    def repository_storage_path
+      Gitlab.config.repositories.storages[repository_storage]['path']
+    end
+  end
+
+  DOWNTIME = false
+
+  def up
+    return unless system_namespace
+
+    old_path = system_namespace.path
+    old_full_path = system_namespace.full_path
+    # Only remove the last occurrence of the path name to get the parent namespace path
+    namespace_path = remove_last_occurrence(old_full_path, old_path)
+    new_path = rename_path(namespace_path, old_path)
+    new_full_path = join_namespace_path(namespace_path, new_path)
+
+    Namespace.where(id: system_namespace).update_all(path: new_path) # skips callbacks & validations
+
+    replace_statement = replace_sql(Route.arel_table[:path], old_full_path, new_full_path)
+    route_matches = [old_full_path, "#{old_full_path}/%"]
+
+    update_column_in_batches(:routes, :path, replace_statement) do |table, query|
+      query.where(Route.arel_table[:path].matches_any(route_matches))
+    end
+
+    clear_cache_for_namespace(system_namespace)
+
+    # tasks here are based on `Namespace#move_dir`
+    move_repositories(system_namespace, old_full_path, new_full_path)
+    move_namespace_folders(uploads_dir, old_full_path, new_full_path) if file_storage?
+    move_namespace_folders(pages_dir, old_full_path, new_full_path)
+  end
+
+  def down
+    # nothing to do
+  end
+
+  def remove_last_occurrence(string, pattern)
+    string.reverse.sub(pattern.reverse, "").reverse
+  end
+
+  def move_namespace_folders(directory, old_relative_path, new_relative_path)
+    old_path = File.join(directory, old_relative_path)
+    return unless File.directory?(old_path)
+
+    new_path = File.join(directory, new_relative_path)
+    FileUtils.mv(old_path, new_path)
+  end
+
+  def move_repositories(namespace, old_full_path, new_full_path)
+    repo_paths_for_namespace(namespace).each do |repository_storage_path|
+      # Ensure old directory exists before moving it
+      gitlab_shell.add_namespace(repository_storage_path, old_full_path)
+
+      unless gitlab_shell.mv_namespace(repository_storage_path, old_full_path, new_full_path)
+        say "Exception moving path #{repository_storage_path} from #{old_full_path} to #{new_full_path}"
+      end
+    end
+  end
+
+  def rename_path(namespace_path, path_was)
+    counter = 0
+    path = "#{path_was}#{counter}"
+
+    while route_exists?(join_namespace_path(namespace_path, path))
+      counter += 1
+      path = "#{path_was}#{counter}"
+    end
+
+    path
+  end
+
+  def route_exists?(full_path)
+    Route.where(Route.arel_table[:path].matches(full_path)).any?
+  end
+
+  def join_namespace_path(namespace_path, path)
+    if namespace_path.present?
+      File.join(namespace_path, path)
+    else
+      path
+    end
+  end
+
+  def system_namespace
+    @system_namespace ||= Namespace.where(parent_id: nil)
+                            .where(arel_table[:path].matches(system_namespace_path))
+                            .first
+  end
+
+  def system_namespace_path
+    "system"
+  end
+
+  def clear_cache_for_namespace(namespace)
+    project_ids = projects_for_namespace(namespace).pluck(:id)
+
+    update_column_in_batches(:projects, :description_html, nil) do |table, query|
+      query.where(table[:id].in(project_ids))
+    end
+
+    update_column_in_batches(:issues, :description_html, nil) do |table, query|
+      query.where(table[:project_id].in(project_ids))
+    end
+
+    update_column_in_batches(:merge_requests, :description_html, nil) do |table, query|
+      query.where(table[:target_project_id].in(project_ids))
+    end
+
+    update_column_in_batches(:notes, :note_html, nil) do |table, query|
+      query.where(table[:project_id].in(project_ids))
+    end
+
+    update_column_in_batches(:milestones, :description_html, nil) do |table, query|
+      query.where(table[:project_id].in(project_ids))
+    end
+  end
+
+  def projects_for_namespace(namespace)
+    namespace_ids = child_ids_for_parent(namespace, ids: [namespace.id])
+    namespace_or_children = Project.arel_table[:namespace_id].in(namespace_ids)
+    Project.unscoped.where(namespace_or_children)
+  end
+
+  # This won't scale to huge trees, but it should do for a handful of namespaces
+  # called `system`.
+  def child_ids_for_parent(namespace, ids: [])
+    namespace.children.each do |child|
+      ids << child.id
+      child_ids_for_parent(child, ids: ids) if child.children.any?
+    end
+    ids
+  end
+
+  def repo_paths_for_namespace(namespace)
+    projects_for_namespace(namespace).distinct
+      .select(:repository_storage).map(&:repository_storage_path)
+  end
+
+  def uploads_dir
+    File.join(Rails.root, "public", "uploads")
+  end
+
+  def pages_dir
+    Settings.pages.path
+  end
+
+  def file_storage?
+    CarrierWave::Uploader::Base.storage == CarrierWave::Storage::File
+  end
+
+  def arel_table
+    Namespace.arel_table
+  end
+end