Add command to dump a course to stdout as a tar.gz file

lms/djangoapps/courseware/management/commands/export_course.py

+"""
+A Django command that exports a course to a tar.gz file.
+"""
+
+import shutil
+import tarfile
+from tempfile import mkdtemp
+from textwrap import dedent
+
+from path import path
+
+from django.core.management.base import BaseCommand, CommandError
+
+from xmodule.modulestore.django import modulestore
+from xmodule.contentstore.django import contentstore
+from xmodule.modulestore.xml_exporter import export_to_xml
+
+
+class Command(BaseCommand):
+    """
+    Export a course to XML. The output is compressed as a tar.gz file
+
+    """
+    args = "<course_id> <output_filename>"
+    help = dedent(__doc__).strip()
+
+    def handle(self, *args, **options):
+        try:
+            course_id = args[0]
+            filename = args[1]
+        except IndexError:
+            raise CommandError("Insufficient arguments")
+
+        export_course_to_tarfile(course_id, filename)
+
+
+def export_course_to_tarfile(course_id, filename):
+    """Exports a course into a tar.gz file"""
+    tmp_dir = mkdtemp()
+    try:
+        course_dir = export_course_to_directory(course_id, tmp_dir)
+        compress_directory(course_dir, filename)
+    finally:
+        shutil.rmtree(tmp_dir)
+
+
+def export_course_to_directory(course_id, root_dir):
+    """Export course into a directory"""
+    store = modulestore()
+    course = store.get_course(course_id)
+    if course is None:
+        raise CommandError("Invalid course_id")
+
+    course_name = course.location.course_id.replace('/', '-')
+    export_to_xml(store, None, course.location, root_dir, course_name)
+
+    course_dir = path(root_dir) / course_name
+    return course_dir
+
+
+def compress_directory(directory, filename):
+    """Compress a directrory into a tar.gz file"""
+    mode = 'w:gz'
+    name = path(directory).name
+    with tarfile.open(filename, mode) as tar_file:
+        tar_file.add(directory, arcname=name)

lms/djangoapps/courseware/tests/test_commands.py

 """Tests for Django management commands"""
 
 import json
+import shutil
 from StringIO import StringIO
+import tarfile
+from tempfile import mkdtemp
+
+from path import path
 
 from django.core.management import call_command
 from django.test.utils import override_settings
@@ -46,7 +51,10 @@ class CommandsTestCase(CommandTestCase):
         self.assertEqual(self.loaded_courses, dumped_courses)
 
     def test_dump_course_structure(self):
+        dumped_courses = self.call_command('dump_course_ids').split('\n')
+        self.assertEqual(self.loaded_courses, dumped_courses)
 
+    def test_dump_course_structure(self):
         args = ['edX/simple/2012_Fall']
         kwargs = {'modulestore': 'default'}
         output = self.call_command('dump_course_structure', *args, **kwargs)
@@ -71,3 +79,34 @@ class CommandsTestCase(CommandTestCase):
         # Check if there is the right number of elements
 
         self.assertEqual(len(dump), 16)
+
+    def test_export_course(self):
+        tmp_dir = path(mkdtemp())
+        filename = tmp_dir / 'test.tar.gz'
+        try:
+            self.run_export_course(filename)
+            with tarfile.open(filename) as tar_file:
+                self.check_export_file(tar_file)
+
+        finally:
+            shutil.rmtree(tmp_dir)
+
+    def run_export_course(self, filename):  # pylint: disable=missing-docstring
+        args = ['edX/simple/2012_Fall', filename]
+        kwargs = {'modulestore': 'default'}
+        self.call_command('export_course', *args, **kwargs)
+
+    def check_export_file(self, tar_file):  # pylint: disable=missing-docstring
+        names = tar_file.getnames()
+
+        # Check if some of the files are present.
+
+        # The rest is of the code should be covered by the tests for
+        # xmodule.modulestore.xml_exporter, used by the dump_course command
+
+        assert_in = self.assertIn
+        assert_in('edX-simple-2012_Fall', names)
+        assert_in('edX-simple-2012_Fall/policies/2012_Fall/policy.json', names)
+        assert_in('edX-simple-2012_Fall/html/toylab.html', names)
+        assert_in('edX-simple-2012_Fall/videosequence/A_simple_sequence.xml', names)
+        assert_in('edX-simple-2012_Fall/sequential/Lecture_2.xml', names)