initial version

Change-Id: I699e0ab082657880998d8618fe29eb7f56c6c661

watcher/common/utils.py

@@ -0,0 +1,99 @@
+# -*- encoding: utf-8 -*-
+# Copyright (c) 2015 b<>com
+#
+# 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.
+
+"""Utilities and helper functions."""
+
+from oslo_config import cfg
+
+import re
+import six
+import uuid
+
+
+from watcher.common.i18n import _LW
+from watcher.openstack.common import log as logging
+
+UTILS_OPTS = [
+    cfg.StrOpt('rootwrap_config',
+               default="/etc/watcher/rootwrap.conf",
+               help='Path to the rootwrap configuration file to use for '
+                    'running commands as root.'),
+    cfg.StrOpt('tempdir',
+               help='Explicitly specify the temporary working directory.'),
+]
+
+CONF = cfg.CONF
+CONF.register_opts(UTILS_OPTS)
+
+LOG = logging.getLogger(__name__)
+
+
+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, six.string_types):
+        LOG.warn(_LW("Failed to remove trailing character. Returning original "
+                     "object. Supplied object is not a string: %s,"), value)
+        return value
+
+    return value.rstrip(chars) or value
+
+
+def generate_uuid():
+    return str(uuid.uuid4())
+
+
+def is_int_like(val):
+    """Check if a value looks like an int."""
+    try:
+        return str(int(val)) == str(val)
+    except Exception:
+        return False
+
+
+def is_uuid_like(val):
+    """Returns validation of a value as a UUID.
+
+    For our purposes, a UUID is a canonical form string:
+    aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa
+
+    """
+    try:
+        return str(uuid.UUID(val)) == val
+    except (TypeError, ValueError, AttributeError):
+        return False
+
+
+def is_hostname_safe(hostname):
+    """Determine if the supplied hostname is RFC compliant.
+
+    Check that the supplied hostname conforms to:
+        * http://en.wikipedia.org/wiki/Hostname
+        * http://tools.ietf.org/html/rfc952
+        * http://tools.ietf.org/html/rfc1123
+
+    :param hostname: The hostname to be validated.
+    :returns: True if valid. False if not.
+
+    """
+    m = '^[a-z0-9]([a-z0-9\-]{0,61}[a-z0-9])?$'
+    return (isinstance(hostname, six.string_types) and
+            (re.match(m, hostname) is not None))