Merge branch 'feature/import-export-docs' into 'master'

import/export docs

Added documentation for and closes https://gitlab.com/gitlab-org/gitlab-ce/issues/3050

Also added a couple of rake tasks that might be useful.

See merge request !4732

doc/README.md

@@ -7,7 +7,8 @@
 - [GitLab as OAuth2 authentication service provider](integration/oauth_provider.md). It allows you to login to other applications from GitLab.
 - [Container Registry](container_registry/README.md) Learn how to use GitLab Container Registry.
 - [GitLab Basics](gitlab-basics/README.md) Find step by step how to start working on your commandline and on GitLab.
-- [Importing to GitLab](workflow/importing/README.md)
+- [Importing to GitLab](workflow/importing/README.md).
+- [Importing and exporting projects between instances](user/project/settings/import_export.md).
 - [Markdown](markdown/markdown.md) GitLab's advanced formatting system.
 - [Migrating from SVN](workflow/importing/migrating_from_svn.md) Convert a SVN repository to Git and GitLab.
 - [Permissions](permissions/permissions.md) Learn what each role in a project (external/guest/reporter/developer/master/owner) can do.

doc/administration/raketasks/project_import_export.md

+# Project import/export
+
+>**Note:**
+  - This feature was [introduced][ce-3050] in GitLab 8.9
+  - Importing will not be possible if the import instance version is lower
+    than that of the exporter.
+  - For existing installations, the project import option has to be enabled in
+    application settings (`/admin/application_settings`) under 'Import sources'.
+  - The exports are stored in a temporary [shared directory][tmp] and are deleted
+    every 24 hours by a specific worker.
+
+The GitLab Import/Export version can be checked by using:
+
+```bash
+# Omnibus installations
+sudo gitlab-rake gitlab:import_export:version
+
+# Installations from source
+bundle exec rake gitlab:import_export:version RAILS_ENV=production
+```
+
+The current list of DB tables that will get exported can be listed by using:
+
+```bash
+# Omnibus installations
+sudo gitlab-rake gitlab:import_export:data
+
+# Installations from source
+bundle exec rake gitlab:import_export:data RAILS_ENV=production
+```
+
+[ce-3050]: https://gitlab.com/gitlab-org/gitlab-ce/issues/3050
+[tmp]: ../../development/shared_files.md

doc/user/project/settings/import_export.md

+# Project import/export
+
+>**Notes:**
+  - This feature was [introduced][ce-3050] in GitLab 8.9
+  - Importing will not be possible if the import instance version is lower
+    than that of the exporter.
+  - For existing installations, the project import option has to be enabled in
+    application settings (`/admin/application_settings`) under 'Import sources'.
+    Ask your administrator if you don't see the **GitLab export** button when
+    creating a new project.
+  - You can find some useful raketasks if you are an administrator in the
+    [import_export](../../../administration/raketasks/project_import_export.md)
+    raketask.
+  - The exports are stored in a temporary [shared directory][tmp] and are deleted
+    every 24 hours by a specific worker.
+
+Existing projects running on any GitLab instance or GitLab.com can be exported
+with all their related data and be moved into a new GitLab instance.
+
+## Exported contents
+
+The following items will be exported:
+
+- Project and wiki repositories
+- Project uploads
+- Project configuration including web hooks and services
+- Issues with comments, merge requests with diffs and comments, labels, milestones, snippets,
+  and other project entities
+
+The following items will NOT be exported:
+
+- Build traces and artifacts
+- LFS objects
+
+## Exporting a project and its data
+
+1. Go to the project settings page by clicking on **Edit Project**:
+
+    ![Project settings button](img/settings_edit_button.png)
+
+1. Scroll down to find the **Export project** button:
+
+    ![Export button](img/import_export_export_button.png)
+
+1. Once the export is generated, you should receive an e-mail with a link to
+   download the file:
+
+    ![Email download link](img/import_export_mail_link.png)
+
+1. Alternatively, you can come back to the project settings and download the
+   file from there, or generate a new export. Once the file available, the page
+   should show the **Download export** button:
+
+    ![Download export](img/import_export_download_export.png)
+
+## Importing the project
+
+1. The new GitLab project import feature is at the far right of the import
+   options when creating a New Project. Make sure you are in the right namespace
+   and you have entered a project name. Click on **GitLab export**:
+
+    ![New project](img/import_export_new_project.png)
+
+1. You can see where the project will be imported to. You can now select file
+   exported previously:
+
+    ![Select file](img/import_export_select_file.png)
+
+1. Click on **Import project** to begin importing. Your newly imported project
+   page will appear soon.
+
+[ce-3050]: https://gitlab.com/gitlab-org/gitlab-ce/issues/3050
+[tmp]: ../../../development/shared_files.md

lib/tasks/gitlab/import_export.rake

+namespace :gitlab do
+  namespace :import_export do
+    desc "GitLab | Show Import/Export version"
+    task version: :environment do
+      puts "Import/Export v#{Gitlab::ImportExport.version}"
+    end
+
+    desc "GitLab | Display exported DB structure"
+    task data: :environment do
+      puts YAML.load_file(Gitlab::ImportExport.config_file)['project_tree'].to_yaml(:SortKeys => true)
+    end
+  end
+end