bitbake: layerindexlib: Initial layer index processing module implementation

The layer index module is expected to be used by various parts of the system
in order to access a layerindex-web (such as layers.openembedded.org) and
perform basic processing on the information, such as dependency scanning.

Along with the layerindex implementation are associated tests.  The tests
properly honor BB_SKIP_NETTESTS='yes' to prevent test failures.

Tests Implemented:
   - Branch, LayerItem, LayerBranch, LayerDependency, Recipe, Machine and
      Distro objects
   - LayerIndex setup using the layers.openembedded.org restapi
   - LayerIndex storing and retrieving from a file
   - LayerIndex verify dependency resolution ordering
   - LayerIndex setup using simulated cooker data

(Bitbake rev: fd0ee6c10dbb5592731e56f4c592fe687682a3e6)

Signed-off-by: Mark Hatle <mark.hatle@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/layerindexlib/tests/common.py

@@ -0,0 +1,43 @@
+# Copyright (C) 2017-2018 Wind River Systems, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+import unittest
+import tempfile
+import os
+import bb
+
+import logging
+
+class LayersTest(unittest.TestCase):
+
+    def setUp(self):
+        self.origdir = os.getcwd()
+        self.d = bb.data.init()
+        # At least one variable needs to be set
+        self.d.setVar('DL_DIR', os.getcwd())
+
+        if os.environ.get("BB_SKIP_NETTESTS") == "yes":
+            self.d.setVar('BB_NO_NETWORK', '1')
+
+        self.tempdir = tempfile.mkdtemp()
+        self.logger = logging.getLogger("BitBake")
+
+    def tearDown(self):
+        os.chdir(self.origdir)
+        if os.environ.get("BB_TMPDIR_NOCLEAN") == "yes":
+            print("Not cleaning up %s. Please remove manually." % self.tempdir)
+        else:
+            bb.utils.prunedir(self.tempdir)
+