Default to host CPU architecture if none is supplied

Currently the only way to specify the CPU architecture of the overcloud
images is by setting it in the appropriate yaml file.  This is fine
until you need to install a single package on multiple CPU architectures.
Then you're either going to attempt to build the wrong image type or you
have to edit the yaml files, which makes problems for upgrades.

This change removes the default architecture from the yaml files and
defaults to the appropriate DiB architecture based on running kernel.

This enables builds on multiple CPU architectures from a single
unmodified package

Change-Id: I34f00a30c1e07869243fb95a437e05d6973a97da

image-yaml/overcloud-hardened-images-centos7.yaml

@@ -1,7 +1,6 @@
 disk_images:
   -
     imagename: overcloud-hardened-full
-    arch: amd64
     type: qcow2
     distro: centos7
     elements:

image-yaml/overcloud-hardened-images-rhel7.yaml

@@ -1,6 +1,5 @@
 disk_images:
   -
     imagename: overcloud-hardened-full
-    arch: amd64
     type: qcow2
     distro: rhel7

image-yaml/overcloud-hardened-images.yaml

@@ -1,7 +1,6 @@
 disk_images:
   -
     imagename: overcloud-hardened-full
-    arch: amd64
     type: qcow2
     elements:
       - dhcp-all-interfaces

image-yaml/overcloud-images-centos7.yaml

@@ -1,7 +1,6 @@
 disk_images:
   -
     imagename: overcloud-full
-    arch: amd64
     type: qcow2
     distro: centos7
     elements:
@@ -12,7 +11,6 @@ disk_images:
       - yum-plugin-priorities
   -
     imagename: ironic-python-agent
-    arch: amd64
     type: qcow2
     distro: centos7
     elements:

image-yaml/overcloud-images-rhel7.yaml

@@ -1,13 +1,11 @@
 disk_images:
   -
     imagename: overcloud-full
-    arch: amd64
     type: qcow2
     distro: rhel7
     environment:
       FS_TYPE: xfs
   -
     imagename: ironic-python-agent
-    arch: amd64
     type: qcow2
     distro: rhel7

image-yaml/overcloud-images.yaml

@@ -1,7 +1,6 @@
 disk_images:
   -
     imagename: overcloud-full
-    arch: amd64
     type: qcow2
     elements:
       - baremetal
@@ -41,7 +40,6 @@ disk_images:
       DIB_PYTHON_VERSION: '2'
   -
     imagename: ironic-python-agent
-    arch: amd64
     # This is bogus, but there's no initrd type in diskimage-builder
     type: qcow2
     # So we just override the extension instead

image-yaml/overcloud-odl-rhel7.yaml

@@ -2,7 +2,6 @@ disk_images:
       -
          imagename: overcloud-odl
          builder: dib
-         arch: amd64
          type: qcow2
          distro: rhel7
          elements:

releasenotes/notes/default-arch-selection-d5fd2fcdba725dd4.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    The default architecure for image builds now defaults to the cpu of the
+    host instead of x86_64/amd64.  This allows for a single package of
+    tripleo-common to be used across multiple architectures to generate images.

tripleo_common/arch.py

@@ -0,0 +1,34 @@
+# -*- coding: utf-8 -*-
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+Simple routines to map host architectures as expected by various components.
+"""
+
+import os
+
+
+def kernel_arch():
+    """Return the kernel arch."""
+    return os.uname()[4]
+
+
+def dib_arch():
+    """Return the kernel arch or the more appripriate DiB arch."""
+    return {'x86_64': 'amd64'}.get(kernel_arch(), kernel_arch())
+
+
+def cirros_arch():
+    """Return the kernel arch or the more appripriate cirros arch."""
+    return {'ppc64le': 'powerpc'}.get(kernel_arch(), kernel_arch())

tripleo_common/image/build.py

@@ -19,6 +19,7 @@ import re
 from oslo_log import log
 from oslo_utils import strutils
 
+import tripleo_common.arch
 from tripleo_common.image.base import BaseImageManager
 from tripleo_common.image.exception import ImageSpecificationException
 from tripleo_common.image.image_builder import ImageBuilder
@@ -48,7 +49,7 @@ class ImageBuildManager(BaseImageManager):
         disk_images = self.load_config_files(self.DISK_IMAGES)
 
         for image in disk_images:
-            arch = image.get('arch', 'amd64')
+            arch = image.get('arch', tripleo_common.arch.dib_arch())
             image_type = image.get('type', 'qcow2')
             image_name = image.get('imagename')
             builder = image.get('builder', 'dib')

tripleo_common/tests/test_arch.py

@@ -0,0 +1,46 @@
+# -*- coding: utf-8 -*-
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2017, Red Hat, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+"""
+Test cases for tripleo_common.arch module.
+"""
+
+import mock
+
+from unittest import TestCase
+
+from tripleo_common import arch
+
+
+class ArchTestCase(TestCase):
+    def test_kernel_arch(self):
+        for (expected, _arch) in [('x86_64', 'x86_64'),
+                                  ('ppc64le', 'ppc64le')]:
+            with mock.patch('os.uname', return_value=('', '', '', '', _arch)):
+                self.assertEqual(expected, arch.kernel_arch())
+
+    def test_dib_arch(self):
+        for (expected, _arch) in [('amd64', 'x86_64'),
+                                  ('ppc64le', 'ppc64le')]:
+            with mock.patch('os.uname', return_value=('', '', '', '', _arch)):
+                self.assertEqual(expected, arch.dib_arch())
+
+    def test_cirros_arch(self):
+        for (expected, _arch) in [('x86_64', 'x86_64'),
+                                  ('powerpc', 'ppc64le')]:
+            with mock.patch('os.uname', return_value=('', '', '', '', _arch)):
+                self.assertEqual(expected, arch.cirros_arch())