heat/heat/engine/resources/openstack/heat/wait_condition.py

#
#    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.

from oslo_log import log as logging
from oslo_serialization import jsonutils
from oslo_utils import timeutils
import six

from heat.common.i18n import _
from heat.engine import attributes
from heat.engine import constraints
from heat.engine import properties
from heat.engine import resource
from heat.engine.resources import wait_condition as wc_base
from heat.engine import support

LOG = logging.getLogger(__name__)


class HeatWaitCondition(resource.Resource):
    """Resource for handling signals received by WaitConditionHandle.

    Resource takes WaitConditionHandle and starts to create. Resource is in
    CREATE_IN_PROGRESS status until WaitConditionHandle doesn't receive
    sufficient number of successful signals (this number can be specified with
    count property) and successfully creates after that, or fails due to
    timeout.
    """

    support_status = support.SupportStatus(version='2014.2')

    PROPERTIES = (
        HANDLE, TIMEOUT, COUNT,
    ) = (
        'handle', 'timeout', 'count',
    )

    ATTRIBUTES = (
        DATA,
    ) = (
        'data',
    )

    properties_schema = {
        HANDLE: properties.Schema(
            properties.Schema.STRING,
            _('A reference to the wait condition handle used to signal this '
              'wait condition.'),
            required=True
        ),
        TIMEOUT: properties.Schema(
            properties.Schema.NUMBER,
            _('The number of seconds to wait for the correct number of '
              'signals to arrive.'),
            required=True,
            constraints=[
                constraints.Range(1, 43200),
            ]
        ),
        COUNT: properties.Schema(
            properties.Schema.INTEGER,
            _('The number of success signals that must be received before '
              'the stack creation process continues.'),
            constraints=[
                constraints.Range(min=1),
            ],
            default=1,
            update_allowed=True
        ),
    }

    attributes_schema = {
        DATA: attributes.Schema(
            _('JSON string containing data associated with wait '
              'condition signals sent to the handle.'),
            cache_mode=attributes.Schema.CACHE_NONE,
            type=attributes.Schema.STRING
        ),
    }

    def _get_handle_resource(self):
        return self.stack.resource_by_refid(self.properties[self.HANDLE])

    def _validate_handle_resource(self, handle):
        if handle is not None and isinstance(
                handle, wc_base.BaseWaitConditionHandle):
            return
        LOG.debug("Got %r instead of wait condition handle", handle)
        hn = handle.name if handle else self.properties[self.HANDLE]
        msg = _('%s is not a valid wait condition handle.') % hn
        raise ValueError(msg)

    def _wait(self, handle, started_at, timeout_in):
        if timeutils.is_older_than(started_at, timeout_in):
            exc = wc_base.WaitConditionTimeout(self, handle)
            LOG.info('%(name)s Timed out (%(timeout)s)',
                     {'name': str(self), 'timeout': str(exc)})
            raise exc

        handle_status = handle.get_status()

        if any(s != handle.STATUS_SUCCESS for s in handle_status):
            failure = wc_base.WaitConditionFailure(self, handle)
            LOG.info('%(name)s Failed (%(failure)s)',
                     {'name': str(self), 'failure': str(failure)})
            raise failure

        if len(handle_status) >= self.properties[self.COUNT]:
            LOG.info("%s Succeeded", str(self))
            return True
        return False

    def handle_create(self):
        handle = self._get_handle_resource()
        self._validate_handle_resource(handle)
        started_at = timeutils.utcnow()
        return handle, started_at, float(self.properties[self.TIMEOUT])

    def check_create_complete(self, data):
        return self._wait(*data)

    def handle_update(self, json_snippet, tmpl_diff, prop_diff):
        if prop_diff:
            self.properties = json_snippet.properties(self.properties_schema,
                                                      self.context)

        handle = self._get_handle_resource()
        started_at = timeutils.utcnow()
        return handle, started_at, float(self.properties[self.TIMEOUT])

    def check_update_complete(self, data):
        return self._wait(*data)

    def handle_delete(self):
        handle = self._get_handle_resource()
        if handle:
            handle.metadata_set({})

    def _resolve_attribute(self, key):
        handle = self._get_handle_resource()
        if handle is None:
            return ''
        if key == self.DATA:
            meta = handle.metadata_get(refresh=True)
            res = {k: meta[k][handle.DATA] for k in meta}
            LOG.debug('%(name)s.GetAtt(%(key)s) == %(res)s'
                      % {'name': self.name,
                         'key': key,
                         'res': res})

            return six.text_type(jsonutils.dumps(res))


def resource_mapping():
    return {
        'OS::Heat::WaitCondition': HeatWaitCondition,
    }