Add common utils

Taken from ceilometerclient. Will be useful for printing output and
importing versioned modules.

tuskarclient/common/utils.py

@@ -0,0 +1,133 @@
+# Copyright 2012 OpenStack LLC.
+# All Rights Reserved.
+#
+#    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.
+
+import os
+import sys
+import textwrap
+import uuid
+
+import prettytable
+
+from tuskarclient import exc
+from tuskarclient.openstack.common import importutils
+
+
+# Decorator for cli-args
+def arg(*args, **kwargs):
+    def _decorator(func):
+        # Because of the sematics of decorator composition if we just append
+        # to the options list positional options will appear to be backwards.
+        func.__dict__.setdefault('arguments', []).insert(0, (args, kwargs))
+        return func
+    return _decorator
+
+
+def pretty_choice_list(l):
+    return ', '.join("'%s'" % i for i in l)
+
+
+def print_list(objs, fields, field_labels, formatters={}, sortby=0):
+    pt = prettytable.PrettyTable([f for f in field_labels],
+                                 caching=False, print_empty=False)
+    pt.align = 'l'
+
+    for o in objs:
+        row = []
+        for field in fields:
+            if field in formatters:
+                row.append(formatters[field](o))
+            else:
+                data = getattr(o, field, '')
+                row.append(data)
+        pt.add_row(row)
+    print pt.get_string(sortby=field_labels[sortby])
+
+
+def print_dict(d, dict_property="Property", wrap=0):
+    pt = prettytable.PrettyTable([dict_property, 'Value'],
+                                 caching=False, print_empty=False)
+    pt.align = 'l'
+    for k, v in d.iteritems():
+        # convert dict to str to check length
+        if isinstance(v, dict):
+            v = str(v)
+        if wrap > 0:
+            v = textwrap.fill(str(v), wrap)
+        # if value has a newline, add in multiple rows
+        # e.g. fault with stacktrace
+        if v and isinstance(v, basestring) and r'\n' in v:
+            lines = v.strip().split(r'\n')
+            col1 = k
+            for line in lines:
+                pt.add_row([col1, line])
+                col1 = ''
+        else:
+            pt.add_row([k, v])
+    print pt.get_string()
+
+
+def find_resource(manager, name_or_id):
+    """Helper for the _find_* methods."""
+    # first try to get entity as integer id
+    try:
+        if isinstance(name_or_id, int) or name_or_id.isdigit():
+            return manager.get(int(name_or_id))
+    except exc.NotFound:
+        pass
+
+    # now try to get entity as uuid
+    try:
+        uuid.UUID(str(name_or_id))
+        return manager.get(name_or_id)
+    except (ValueError, exc.NotFound):
+        pass
+
+    # finally try to find entity by name
+    try:
+        return manager.find(name=name_or_id)
+    except exc.NotFound:
+        msg = "No %s with a name or ID of '%s' exists." % \
+              (manager.resource_class.__name__.lower(), name_or_id)
+        raise exc.CommandError(msg)
+
+
+def string_to_bool(arg):
+    return arg.strip().lower() in ('t', 'true', 'yes', '1')
+
+
+def env(*vars, **kwargs):
+    """Search for the first defined of possibly many env vars
+
+    Returns the first environment variable defined in vars, or
+    returns the default defined in kwargs.
+    """
+    for v in vars:
+        value = os.environ.get(v, None)
+        if value:
+            return value
+    return kwargs.get('default', '')
+
+
+def import_versioned_module(version, submodule=None):
+    module = 'tuskarclient.v%s' % version
+    if submodule:
+        module = '.'.join((module, submodule))
+    return importutils.import_module(module)
+
+
+def exit(msg=''):
+    if msg:
+        print >> sys.stderr, msg
+    sys.exit(1)

tuskarclient/tests/test_utils.py

@@ -0,0 +1,47 @@
+# Copyright 2013 OpenStack LLC.
+# All Rights Reserved.
+#
+#    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.
+
+
+import cStringIO
+import sys
+
+from tuskarclient.common import utils
+from tuskarclient.tests import utils as test_utils
+
+
+class UtilsTest(test_utils.TestCase):
+
+    def test_prettytable(self):
+        class Struct:
+            def __init__(self, **entries):
+                self.__dict__.update(entries)
+
+        # test that the prettytable output is wellformatted (left-aligned)
+        saved_stdout = sys.stdout
+        try:
+            sys.stdout = output_dict = cStringIO.StringIO()
+            utils.print_dict({'K': 'k', 'Key': 'Value'})
+
+        finally:
+            sys.stdout = saved_stdout
+
+        self.assertEqual(output_dict.getvalue(), '''\
++----------+-------+
+| Property | Value |
++----------+-------+
+| K        | k     |
+| Key      | Value |
++----------+-------+
+''')