Debian: Fix patch controller prior to bootstrap

If /etc/resolv.conf is empty  the patch controller
will raise an uncaught exception due to osprofiler
attempting to validate dns.

osprofiler is unused by patching, so the module is
disabled by the patch controller.

All sw-patch CLI commands will fail prior to
setting up resolv.conf (bootstrapping) without this
fix, since there is no working patch controller

sysinv.common.utils also pulls in dns, so the two
utility methods are cloned into patching repo.

Test Plan:
 PASS Build/Install AIO-SX Debian
 PASS upload a patch

Story: 2009969
Task: 45838
Signed-off-by: Al Bailey <al.bailey@windriver.com>
Change-Id: I0975f5b54a17a0989a78f6ac39160af0b3e26013

sw-patch/bin/sw-patch-controller-daemon

@@ -1,7 +1,7 @@
 #!/usr/bin/python
 
 """
-Copyright (c) 2014 Wind River Systems, Inc.
+Copyright (c) 2014-2022 Wind River Systems, Inc.
 
 SPDX-License-Identifier: Apache-2.0
 
@@ -9,6 +9,9 @@ SPDX-License-Identifier: Apache-2.0
 
 import sys
 
+# prevent patch_controller from importing osprofiler
+sys.modules['osprofiler'] = None
+
 from cgcs_patch.patch_controller import main
 
 if __name__ == "__main__":

sw-patch/cgcs-patch/cgcs_patch/authapi/auth_token.py

@@ -11,9 +11,13 @@
 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 # License for the specific language governing permissions and limitations
 # under the License.
-
+#
+# Copyright (c) 2022 Wind River Systems, Inc.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
 from keystonemiddleware import auth_token
-from sysinv.common import utils
+from cgcs_patch import utils
 
 
 class AuthTokenMiddleware(auth_token.AuthProtocol):

sw-patch/cgcs-patch/cgcs_patch/authapi/hooks.py

@@ -18,15 +18,16 @@
 #
 # Copyright (c) 2013-2022 Wind River Systems, Inc.
 #
-
-
+# SPDX-License-Identifier: Apache-2.0
+#
 from oslo_config import cfg
 from pecan import hooks
+from webob import exc
 
 from sysinv.common import context
-from sysinv.common import utils
 from sysinv.openstack.common import policy
-from webob import exc
+
+from cgcs_patch import utils
 
 
 class ConfigHook(hooks.PecanHook):

sw-patch/cgcs-patch/cgcs_patch/authapi/policy.py

@@ -22,9 +22,10 @@
 import os.path
 
 from sysinv.common import exception
-from sysinv.common import utils
 from sysinv.openstack.common import policy
 
+from cgcs_patch import utils
+
 
 _POLICY_PATH = None
 _POLICY_CACHE = {}

sw-patch/cgcs-patch/cgcs_patch/utils.py

@@ -1,24 +1,19 @@
 """
-Copyright (c) 2016-2019 Wind River Systems, Inc.
+Copyright (c) 2016-2022 Wind River Systems, Inc.
 
 SPDX-License-Identifier: Apache-2.0
 
 """
-
+import logging
 from netaddr import IPAddress
-import cgcs_patch.constants as constants
+import os
 import socket
-
-try:
-    # Python3
 from socket import if_nametoindex as if_nametoindex_func
-except ImportError:
-    # Python2
-    import ctypes
-    import ctypes.util
 
-    libc = ctypes.CDLL(ctypes.util.find_library('c'))
-    if_nametoindex_func = libc.if_nametoindex
+import cgcs_patch.constants as constants
+
+
+LOG = logging.getLogger('main_logger')
 
 
 def if_nametoindex(name):
@@ -81,3 +76,40 @@ def ip_to_versioned_localhost(ip_address_string):
         return "::1"
     else:
         return "localhost"
+
+
+def read_cached_file(filename, cache_info, reload_func=None):
+    """Read from a file if it has been modified.
+
+    :param cache_info: dictionary to hold opaque cache.
+    :param reload_func: optional function to be called with data when
+                        file is reloaded due to a modification.
+
+    :returns: data from file
+
+    """
+    mtime = os.path.getmtime(filename)
+    if not cache_info or mtime != cache_info.get('mtime'):
+        LOG.debug("Reloading cached file %s", filename)
+        with open(filename) as fap:
+            cache_info['data'] = fap.read()
+        cache_info['mtime'] = mtime
+        if reload_func:
+            reload_func(cache_info['data'])
+    return cache_info['data']
+
+
+def safe_rstrip(value, chars=None):
+    """Removes trailing characters from a string if that does not make it empty
+
+    :param value: A string value that will be stripped.
+    :param chars: Characters to remove.
+    :return: Stripped value.
+
+    """
+    if not isinstance(value, str):
+        LOG.warn("Failed to remove trailing character. Returning original "
+                 "object. Supplied object is not a string: %s", value)
+        return value
+
+    return value.rstrip(chars) or value