fail at startup with no operating-system element

Raise an error if there is no element with “operating-system”
in the element-provides file.

Change-Id: I2242537abc4c610252984c32c286bc6eb25de672

diskimage_builder/element_dependencies.py

@@ -43,7 +43,7 @@ def _get_set(element, fname, elements_dir=None):
 
     sys.stderr.write("ERROR: Element '%s' not found in '%s'\n" %
                      (element, elements_dir))
-    exit(-1)
+    sys.exit(-1)
 
 
 def provides(element, elements_dir=None):
@@ -98,12 +98,17 @@ def expand_dependencies(user_elements, elements_dir=None):
         check_queue.extend(deps - (final_elements | provided))
         final_elements.update(deps)
 
+    if "operating-system" not in provided:
+        sys.stderr.write(
+            "ERROR: Please include an operating system element.\n")
+        sys.exit(-1)
+
     conflicts = set(user_elements) & provided
     if conflicts:
         sys.stderr.write("ERROR: Following elements were explicitly required "
                          "but are provided by other included elements: %s\n" %
                          ", ".join(conflicts))
-        exit(-1)
+        sys.exit(-1)
     return final_elements - provided
 
 

diskimage_builder/tests/test_elementdeps.py

@@ -40,7 +40,10 @@ class TestElementDeps(testtools.TestCase):
         super(TestElementDeps, self).setUp()
         self.element_dir = self.useFixture(fixtures.TempDir()).path
         _populate_element(self.element_dir, 'requires-foo', ['foo'])
-        _populate_element(self.element_dir, 'foo')
+        _populate_element(self.element_dir,
+                          'foo',
+                          [],
+                          ['operating-system'])
         _populate_element(self.element_dir,
                           'requires-requires-foo',
                           ['requires-foo'])
@@ -49,15 +52,21 @@ class TestElementDeps(testtools.TestCase):
                           'provides_virtual',
                           [],
                           ['virtual'])
-        _populate_element(self.element_dir, 'requires_virtual', ['virtual'])
+        _populate_element(self.element_dir,
+                          'requires_virtual',
+                          ['virtual'],
+                          ['operating-system'])
         _populate_element(self.element_dir, 'virtual', ['extra_dependency'])
         _populate_element(self.element_dir, 'extra_dependency', [])
-        _populate_element(self.element_dir, 'circular1', ['circular2'])
+        _populate_element(self.element_dir,
+                          'circular1',
+                          ['circular2'],
+                          ['operating-system'])
         _populate_element(self.element_dir, 'circular2', ['circular1'])
         _populate_element(self.element_dir,
                           'provides_new_virtual',
                           [],
-                          ['new_virtual'])
+                          ['new_virtual', 'operating-system'])
         _populate_element(self.element_dir,
                           'requires_new_virtual',
                           ['new_virtual'])
@@ -87,8 +96,8 @@ class TestElementDeps(testtools.TestCase):
 
     def test_self(self):
         result = element_dependencies.expand_dependencies(
-            ['self'], elements_dir=self.element_dir)
-        self.assertEqual(set(['self']), result)
+            ['self', 'foo'], elements_dir=self.element_dir)
+        self.assertEqual(set(['self', 'foo']), result)
 
     def test_circular(self):
         result = element_dependencies.expand_dependencies(
@@ -114,6 +123,18 @@ class TestElementDeps(testtools.TestCase):
         self.assertEqual(set(['requires_new_virtual', 'provides_new_virtual']),
                          result)
 
+    def test_no_os_element(self):
+        self.assertRaises(SystemExit,
+                          element_dependencies.expand_dependencies,
+                          ['provides_virtual'],
+                          elements_dir=self.element_dir)
+
+    def test_duplicated_os_passed_as_element(self):
+        self.assertRaises(SystemExit,
+                          element_dependencies.expand_dependencies,
+                          ['circular1', 'operating-system'],
+                          elements_dir=self.element_dir)
+
 
 class TestElements(testtools.TestCase):
     def test_depends_on_env(self):

lib/common-functions

@@ -252,7 +252,7 @@ function create_base () {
     if [ -z "$(ls $TMP_MOUNT_PATH | grep -v '^lost+found\|tmp$')" ] ; then
         # No root element copied in. Note the test above allows
         # root.d elements to put things in /tmp
-        echo "Please include at least one distribution root element."
+        echo "Failed to deploy the root element."
         exit 1
     fi