From 2b18513caddf63d6a12be30e4334681979dc9aba Mon Sep 17 00:00:00 2001
From: Ian Wienand <iwienand@redhat.com>
Date: Fri, 10 Jun 2016 14:04:26 +1000
Subject: [PATCH] Convert element_dependencies to logging

Use standard logging module for output.  Add some basic testing of
error messages to the unit-tests.  Use the logging_config module to
setup the logging for interactive use.

Change-Id: Ia23722a7bd00aba336118edb155356a3b3ef6926
---
 diskimage_builder/element_dependencies.py   | 24 +++++++++++++--------
 diskimage_builder/tests/test_elementdeps.py |  9 ++++++++
 2 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/diskimage_builder/element_dependencies.py b/diskimage_builder/element_dependencies.py
index be1c4f1c..b840c558 100644
--- a/diskimage_builder/element_dependencies.py
+++ b/diskimage_builder/element_dependencies.py
@@ -15,9 +15,14 @@
 from __future__ import print_function
 import argparse
 import collections
+import logging
 import os
 import sys
 
+import diskimage_builder.logging_config
+
+logger = logging.getLogger(__name__)
+
 
 def get_elements_dir():
     if not os.environ.get('ELEMENTS_PATH'):
@@ -42,8 +47,7 @@ def _get_set(element, fname, elements_dir=None):
             else:
                 raise
 
-    sys.stderr.write("ERROR: Element '%s' not found in '%s'\n" %
-                     (element, elements_dir))
+    logger.error("Element '%s' not found in '%s'" % (element, elements_dir))
     sys.exit(-1)
 
 
@@ -100,20 +104,22 @@ def expand_dependencies(user_elements, elements_dir=None):
         final_elements.update(deps)
 
     if "operating-system" not in provided:
-        sys.stderr.write(
-            "ERROR: Please include an operating system element.\n")
+        logger.error(
+            "Please include an operating system element.")
         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))
+        logger.error("Following elements were explicitly required "
+                     "but are provided by other included elements: %s" %
+                     ", ".join(conflicts))
         sys.exit(-1)
     return final_elements - provided
 
 
 def main(argv):
+    diskimage_builder.logging_config.setup()
+
     parser = argparse.ArgumentParser()
     parser.add_argument('elements', nargs='+',
                         help='display dependencies of the given elements')
@@ -125,8 +131,8 @@ def main(argv):
     args = parser.parse_args(argv[1:])
 
     if args.expand_dependencies:
-        print("WARNING: expand-dependencies flag is deprecated,  "
-              "and is now on by default.", file=sys.stderr)
+        logger.warning("expand-dependencies flag is deprecated,  "
+                       "and is now on by default.", file=sys.stderr)
 
     print(' '.join(expand_dependencies(args.elements)))
     return 0
diff --git a/diskimage_builder/tests/test_elementdeps.py b/diskimage_builder/tests/test_elementdeps.py
index 7bbcdb49..f6039f84 100644
--- a/diskimage_builder/tests/test_elementdeps.py
+++ b/diskimage_builder/tests/test_elementdeps.py
@@ -12,6 +12,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+import logging
 import os
 
 import fixtures
@@ -39,6 +40,8 @@ class TestElementDeps(testtools.TestCase):
     def setUp(self):
         super(TestElementDeps, self).setUp()
         self.element_dir = self.useFixture(fixtures.TempDir()).path
+        self.log_fixture = self.useFixture(
+            fixtures.FakeLogger(level=logging.DEBUG))
         _populate_element(self.element_dir, 'requires-foo', ['foo'])
         _populate_element(self.element_dir,
                           'foo',
@@ -81,6 +84,8 @@ class TestElementDeps(testtools.TestCase):
         self.assertRaises(SystemExit,
                           element_dependencies.expand_dependencies, ['fake'],
                           self.element_dir)
+        self.assertIn("Element 'fake' not found",
+                      self.log_fixture.output)
 
     def test_transitive_deps(self):
         result = element_dependencies.expand_dependencies(
@@ -128,12 +133,16 @@ class TestElementDeps(testtools.TestCase):
                           element_dependencies.expand_dependencies,
                           ['provides_virtual'],
                           elements_dir=self.element_dir)
+        self.assertIn("Please include an operating system element",
+                      self.log_fixture.output)
 
     def test_duplicated_os_passed_as_element(self):
         self.assertRaises(SystemExit,
                           element_dependencies.expand_dependencies,
                           ['circular1', 'operating-system'],
                           elements_dir=self.element_dir)
+        self.assertIn("provided by other included elements: operating-system",
+                      self.log_fixture.output)
 
 
 class TestElements(testtools.TestCase):