Add values.py processor for environmental overrides of subcharts

This script allows you to have an single environmental YAML file that can be
chunked up for feeding into various subcharts.  This is required as values
input into helm requires the top level namespace be stripped off.  In other
words, a flat namespace.  This allows a single environmental definition that
can be chunked into YAML files for subchart input.

Usage will be documented on the wiki.

common/utils/values/values.py

@@ -0,0 +1,151 @@
+#! /usr/bin/env python
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# 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.
+
+"""
+Usage
+
+$ cat /tmp/globals.yaml
+global:
+  neener: teener
+
+ceph:
+  foo: bar
+  coo: zoo
+  foo:
+    hoo: woo
+
+keystone:
+  goo: baz
+
+---
+
+$ ./values.py -y /tmp/globals.yaml
+2016-12-14 13:02:31,950 values       INFO     Processing YAML file /tmp/globals.yaml
+2016-12-14 13:02:31,951 values       INFO     Writing out /tmp/helmVccaOA/ceph.yaml
+2016-12-14 13:02:31,952 values       INFO     Writing out /tmp/helmVccaOA/keystone.yaml
+
+$ cat /tmp/helmVccaOA/ceph.yaml
+global:
+  neener: teener
+coo: zoo
+foo:
+  hoo: woo
+
+$ cat /tmp/helmVccaOA/keystone.yaml
+global:
+  neener: teener
+goo: baz
+
+---
+
+$ helm install --values=/tmp/helmVccaOA/ceph.yaml ./ceph-0.1.0.tgz --namespace=ceph
+
+"""
+
+import yaml
+import tempfile
+import sys
+import os
+import logging
+import argparse
+from logging.handlers import SysLogHandler
+
+LOG = logging.getLogger('values')
+LOG_FORMAT='%(asctime)s %(name)-12s %(levelname)-8s %(message)s'
+LOG_DATE = '%m-%d %H:%M'
+DESCRIPTION = "Values Generator"
+
+# special top level parameters
+# we will copy to all configs
+COPY_LIST=['global']
+
+def parse_args():
+
+    ap = argparse.ArgumentParser(description=DESCRIPTION)
+    ap.add_argument('-d', '--debug', action='store_true',
+                    default=False, help='Enable debugging')
+    ap.add_argument('-y', '--yaml', action='store',
+                    help='Path to Master YAML File')
+    return ap.parse_args()
+
+def setup_logging(args):
+    level = logging.INFO
+    if args.debug:
+        level = logging.DEBUG
+    logging.basicConfig(level=level, format=LOG_FORMAT, date_fmt=LOG_DATE)
+    handler = SysLogHandler(address='/dev/log')
+    syslog_formatter = logging.Formatter('%(name)s: %(levelname)s %(message)s')
+    handler.setFormatter(syslog_formatter)
+    LOG.addHandler(handler)
+
+def is_path_creatable(pathname):
+    '''
+    `True` if the current user has sufficient permissions to create the passed
+    pathname; `False` otherwise.
+    '''
+    # Parent directory of the passed path. If empty, we substitute the current
+    # working directory (CWD) instead.
+    dirname = os.path.dirname(pathname) or os.getcwd()
+    return os.access(dirname, os.W_OK)
+
+def process_yaml(yaml_path):
+    '''
+    Processes YAML file and generates breakdown of top level
+    keys
+    '''
+
+    # perform some basic validation
+    if not os.path.isfile(yaml_path):
+        LOG.exception("The path %s does not point to a valid file", yaml_path)
+
+    tmp_dir = tempfile.mkdtemp(prefix='helm', dir='/tmp')
+
+    yamldata = yaml.load(open(yaml_path).read())
+    for top_level in yamldata.keys():
+        if top_level in COPY_LIST:
+            continue
+        top_level_path = os.path.join(tmp_dir, top_level + '.yaml')
+        if is_path_creatable(top_level_path):
+
+            with open(top_level_path, 'w') as f:
+                LOG.info("Writing out %s", top_level_path)
+                for item in COPY_LIST:
+                    if item in yamldata.keys():
+                        f.write(yaml.dump({item: yamldata[item]}, default_flow_style=False))
+                f.write(yaml.dump(yamldata[top_level], default_flow_style=False))
+
+        else:
+            LOG.exception("Unable to create path %s based on top level key in %s" % (top_level_path, yaml_path))
+
+def run(args):
+
+    if args.yaml:
+
+        LOG.info("Processing YAML file %s", args.yaml)
+        process_yaml(args.yaml)
+
+if __name__ == '__main__':
+
+    args = parse_args()
+    setup_logging(args)
+
+    try:
+        run(args)
+        sys.exit(0)
+    except Exception as err:
+        LOG.exception(err)
+        sys.exit(1)