Add basic Keystone CLI tests

New cli.output_parser helpers for parsing 'ascii-tables'
 often used in CLIs output.

New basic tests for keystone cli, verifies only read-only
 actions (return codes and basic structure of output).

Change-Id: I4fea08b14e32c62c47e347b401e3f5703836c184
diff --git a/cli/output_parser.py b/cli/output_parser.py
new file mode 100644
index 0000000..840839b
--- /dev/null
+++ b/cli/output_parser.py
@@ -0,0 +1,168 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2013 OpenStack Foundation
+# 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.
+
+"""Collection of utilities for parsing CLI clients output."""
+
+
+import logging
+import re
+
+
+LOG = logging.getLogger(__name__)
+
+
+delimiter_line = re.compile('^\+\-[\+\-]+\-\+$')
+
+
+def details_multiple(output_lines, with_label=False):
+    """Return list of dicts with item details from cli output tables.
+
+    If with_label is True, key '__label' is added to each items dict.
+    For more about 'label' see OutputParser.tables().
+    """
+    items = []
+    tables_ = tables(output_lines)
+    for table_ in tables_:
+        if 'Property' not in table_['headers'] \
+           or 'Value' not in table_['headers']:
+            raise Exception('Invalid structure of table with details')
+        item = {}
+        for value in table_['values']:
+            item[value[0]] = value[1]
+        if with_label:
+            item['__label'] = table_['label']
+        items.append(item)
+    return items
+
+
+def details(output_lines, with_label=False):
+    """Return dict with details of first item (table) found in output."""
+    items = details_multiple(output_lines, with_label)
+    return items[0]
+
+
+def listing(output_lines):
+    """Return list of dicts with basic item info parsed from cli output.
+    """
+
+    items = []
+    table_ = table(output_lines)
+    for row in table_['values']:
+        item = {}
+        for col_idx, col_key in enumerate(table_['headers']):
+            item[col_key] = row[col_idx]
+        items.append(item)
+    return items
+
+
+def tables(output_lines):
+    """Find all ascii-tables in output and parse them.
+
+    Return list of tables parsed from cli output as dicts.
+    (see OutputParser.table())
+
+    And, if found, label key (separated line preceding the table)
+    is added to each tables dict.
+    """
+    tables_ = []
+
+    table_ = []
+    label = None
+
+    start = False
+    header = False
+
+    if not isinstance(output_lines, list):
+        output_lines = output_lines.split('\n')
+
+    for line in output_lines:
+        if delimiter_line.match(line):
+            if not start:
+                start = True
+            elif not header:
+                # we are after head area
+                header = True
+            else:
+                # table ends here
+                start = header = None
+                table_.append(line)
+
+                parsed = table(table_)
+                parsed['label'] = label
+                tables_.append(parsed)
+
+                table_ = []
+                label = None
+                continue
+        if start:
+            table_.append(line)
+        else:
+            if label is None:
+                label = line
+            else:
+                LOG.warn('Invalid line between tables: %s' % line)
+    if len(table_) > 0:
+        LOG.warn('Missing end of table')
+
+    return tables_
+
+
+def table(output_lines):
+    """Parse single table from cli output.
+
+    Return dict with list of column names in 'headers' key and
+    rows in 'values' key.
+    """
+    table_ = {'headers': [], 'values': []}
+    columns = None
+
+    if not isinstance(output_lines, list):
+        output_lines = output_lines.split('\n')
+
+    for line in output_lines:
+        if delimiter_line.match(line):
+            columns = _table_columns(line)
+            continue
+        if '|' not in line:
+            LOG.warn('skipping invalid table line: %s' % line)
+            continue
+        row = []
+        for col in columns:
+            row.append(line[col[0]:col[1]].strip())
+        if table_['headers']:
+            table_['values'].append(row)
+        else:
+            table_['headers'] = row
+
+    return table_
+
+
+def _table_columns(first_table_row):
+    """Find column ranges in output line.
+
+    Return list of touples (start,end) for each column
+    detected by plus (+) characters in delimiter line.
+    """
+    positions = []
+    start = 1  # there is '+' at 0
+    while start < len(first_table_row):
+        end = first_table_row.find('+', start)
+        if end == -1:
+            break
+        positions.append((start, end))
+        start = end + 1
+    return positions