Source code for heat.engine.parser

# vim: tabstop=4 shiftwidth=4 softtabstop=4

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#    Licensed under the Apache License, Version 2.0 (the "License"); you may
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#         http://www.apache.org/licenses/LICENSE-2.0
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import functools
import re

from oslo.config import cfg

from heat.engine import environment
from heat.common import exception
from heat.engine import dependencies
from heat.common import identifier
from heat.engine import resource
from heat.engine import resources
from heat.engine import scheduler
from heat.engine import template
from heat.engine import timestamp
from heat.engine import update
from heat.engine.parameters import Parameters
from heat.engine.template import Template
from heat.engine.clients import Clients
from heat.db import api as db_api

from heat.openstack.common import log as logging
from heat.openstack.common.gettextutils import _

from heat.common.exception import StackValidationFailed

logger = logging.getLogger(__name__)

(PARAM_STACK_NAME, PARAM_REGION) = ('AWS::StackName', 'AWS::Region')


[docs]class Stack(object): ACTIONS = (CREATE, DELETE, UPDATE, ROLLBACK, SUSPEND, RESUME ) = ('CREATE', 'DELETE', 'UPDATE', 'ROLLBACK', 'SUSPEND', 'RESUME') STATUSES = (IN_PROGRESS, FAILED, COMPLETE ) = ('IN_PROGRESS', 'FAILED', 'COMPLETE') created_time = timestamp.Timestamp(functools.partial(db_api.stack_get, show_deleted=True), 'created_at') updated_time = timestamp.Timestamp(functools.partial(db_api.stack_get, show_deleted=True), 'updated_at') _zones = None def __init__(self, context, stack_name, tmpl, env=None, stack_id=None, action=None, status=None, status_reason='', timeout_mins=60, resolve_data=True, disable_rollback=True, parent_resource=None, owner_id=None): ''' Initialise from a context, name, Template object and (optionally) Environment object. The database ID may also be initialised, if the stack is already in the database. ''' if owner_id is None: if re.match("[a-zA-Z][a-zA-Z0-9_.-]*$", stack_name) is None: raise ValueError(_('Invalid stack name %s' ' must contain only alphanumeric or ' '\"_-.\" characters, must start with alpha' ) % stack_name) self.id = stack_id self.owner_id = owner_id self.context = context self.clients = Clients(context) self.t = tmpl self.name = stack_name self.action = action self.status = status self.status_reason = status_reason self.timeout_mins = timeout_mins self.disable_rollback = disable_rollback self.parent_resource = parent_resource self._resources = None self._dependencies = None resources.initialise() self.env = env or environment.Environment({}) self.parameters = Parameters(self.name, self.t, user_params=self.env.params) self._set_param_stackid() if resolve_data: self.outputs = self.resolve_static_data(self.t[template.OUTPUTS]) else: self.outputs = {} @property
[docs] def resources(self): if self._resources is None: template_resources = self.t[template.RESOURCES] self._resources = dict((name, resource.Resource(name, data, self)) for (name, data) in template_resources.items()) return self._resources
@property
[docs] def dependencies(self): if self._dependencies is None: self._dependencies = self._get_dependencies( self.resources.itervalues()) return self._dependencies
[docs] def reset_dependencies(self): self._dependencies = None
@property
[docs] def root_stack(self): ''' Return the root stack if this is nested (otherwise return self). ''' if (self.parent_resource and self.parent_resource.stack): return self.parent_resource.stack.root_stack return self
[docs] def total_resources(self): ''' Total number of resources in a stack, including nested stacks below. ''' total = 0 for res in iter(self.resources.values()): if hasattr(res, 'nested') and res.nested(): total += res.nested().total_resources() total += 1 return total
def _set_param_stackid(self): ''' Update self.parameters with the current ARN which is then provided via the Parameters class as the AWS::StackId pseudo parameter ''' # This can fail if constructor called without a valid context, # as it is in many tests try: stack_arn = self.identifier().arn() except (AttributeError, ValueError, TypeError): logger.warning("Unable to set parameters StackId identifier") else: self.parameters.set_stack_id(stack_arn) @staticmethod def _get_dependencies(resources): '''Return the dependency graph for a list of resources.''' deps = dependencies.Dependencies() for resource in resources: resource.add_dependencies(deps) return deps @classmethod
[docs] def load(cls, context, stack_id=None, stack=None, resolve_data=True, parent_resource=None, show_deleted=True): '''Retrieve a Stack from the database.''' if stack is None: stack = db_api.stack_get(context, stack_id, show_deleted=show_deleted) if stack is None: message = 'No stack exists with id "%s"' % str(stack_id) raise exception.NotFound(message) template = Template.load(context, stack.raw_template_id) env = environment.Environment(stack.parameters) stack = cls(context, stack.name, template, env, stack.id, stack.action, stack.status, stack.status_reason, stack.timeout, resolve_data, stack.disable_rollback, parent_resource, owner_id=stack.owner_id) return stack
[docs] def store(self, backup=False): ''' Store the stack in the database and return its ID If self.id is set, we update the existing stack ''' s = { 'name': self._backup_name() if backup else self.name, 'raw_template_id': self.t.store(self.context), 'parameters': self.env.user_env_as_dict(), 'owner_id': self.owner_id, 'username': self.context.username, 'tenant': self.context.tenant_id, 'action': self.action, 'status': self.status, 'status_reason': self.status_reason, 'timeout': self.timeout_mins, 'disable_rollback': self.disable_rollback, } if self.id: db_api.stack_update(self.context, self.id, s) else: # Create a context containing a trust_id and trustor_user_id # if trusts are enabled if cfg.CONF.deferred_auth_method == 'trusts': trust_context = self.clients.keystone().create_trust_context() new_creds = db_api.user_creds_create(trust_context) else: new_creds = db_api.user_creds_create(self.context) s['user_creds_id'] = new_creds.id new_s = db_api.stack_create(self.context, s) self.id = new_s.id self._set_param_stackid() return self.id
def _backup_name(self): return '%s*' % self.name
[docs] def identifier(self): ''' Return an identifier for this stack. ''' return identifier.HeatIdentifier(self.context.tenant_id, self.name, self.id)
def __iter__(self): ''' Return an iterator over this template's resources in the order that they should be started. ''' return iter(self.dependencies) def __reversed__(self): ''' Return an iterator over this template's resources in the order that they should be stopped. ''' return reversed(self.dependencies) def __len__(self): '''Return the number of resources.''' return len(self.resources) def __getitem__(self, key): '''Get the resource with the specified name.''' return self.resources[key] def __setitem__(self, key, value): '''Set the resource with the specified name to a specific value.''' self.resources[key] = value def __contains__(self, key): '''Determine whether the stack contains the specified resource.''' return key in self.resources
[docs] def keys(self): '''Return a list of resource keys for the stack.''' return self.resources.keys()
def __str__(self): '''Return a human-readable string representation of the stack.''' return 'Stack "%s"' % self.name
[docs] def resource_by_refid(self, refid): ''' Return the resource in this stack with the specified refid, or None if not found ''' for r in self.resources.values(): if r.state in ( (r.CREATE, r.IN_PROGRESS), (r.CREATE, r.COMPLETE), (r.RESUME, r.IN_PROGRESS), (r.RESUME, r.COMPLETE), (r.UPDATE, r.IN_PROGRESS), (r.UPDATE, r.COMPLETE)) and r.FnGetRefId() == refid: return r
[docs] def validate(self): ''' http://docs.amazonwebservices.com/AWSCloudFormation/latest/\ APIReference/API_ValidateTemplate.html ''' # TODO(sdake) Should return line number of invalid reference # Check duplicate names between parameters and resources dup_names = set(self.parameters.keys()) & set(self.resources.keys()) if dup_names: logger.debug("Duplicate names %s" % dup_names) raise StackValidationFailed(message="Duplicate names %s" % dup_names) for res in self: try: result = res.validate() except exception.Error as ex: logger.exception(ex) raise ex except Exception as ex: logger.exception(ex) raise StackValidationFailed(message=str(ex)) if result: raise StackValidationFailed(message=result)
[docs] def requires_deferred_auth(self): ''' Returns whether this stack may need to perform API requests during its lifecycle using the configured deferred authentication method. ''' return any(res.requires_deferred_auth for res in self)
[docs] def state_set(self, action, status, reason): '''Update the stack state in the database.''' if action not in self.ACTIONS: raise ValueError("Invalid action %s" % action) if status not in self.STATUSES: raise ValueError("Invalid status %s" % status) self.action = action self.status = status self.status_reason = reason if self.id is None: return stack = db_api.stack_get(self.context, self.id) stack.update_and_save({'action': action, 'status': status, 'status_reason': reason})
@property
[docs] def state(self): '''Returns state, tuple of action, status.''' return (self.action, self.status)
[docs] def timeout_secs(self): ''' Return the stack creation timeout in seconds, or None if no timeout should be used. ''' if self.timeout_mins is None: return None return self.timeout_mins * 60
[docs] def create(self): ''' Create the stack and all of the resources. ''' def rollback(): if not self.disable_rollback and self.state == (self.CREATE, self.FAILED): self.delete(action=self.ROLLBACK) creator = scheduler.TaskRunner(self.stack_task, action=self.CREATE, reverse=False, post_func=rollback) creator(timeout=self.timeout_secs())
@scheduler.wrappertask
[docs] def stack_task(self, action, reverse=False, post_func=None): ''' A task to perform an action on the stack and all of the resources in forward or reverse dependency order as specfifed by reverse ''' self.state_set(action, self.IN_PROGRESS, 'Stack %s started' % action) stack_status = self.COMPLETE reason = 'Stack %s completed successfully' % action.lower() res = None def resource_action(r): # Find e.g resource.create and call it action_l = action.lower() handle = getattr(r, '%s' % action_l) return handle() action_task = scheduler.DependencyTaskGroup(self.dependencies, resource_action, reverse) try: yield action_task() except exception.ResourceFailure as ex: stack_status = self.FAILED reason = 'Resource %s failed: %s' % (action.lower(), str(ex)) except scheduler.Timeout: stack_status = self.FAILED reason = '%s timed out' % action.title() self.state_set(action, stack_status, reason) if callable(post_func): post_func()
def _backup_stack(self, create_if_missing=True): ''' Get a Stack containing any in-progress resources from the previous stack state prior to an update. ''' s = db_api.stack_get_by_name(self.context, self._backup_name(), owner_id=self.id) if s is not None: logger.debug('Loaded existing backup stack') return self.load(self.context, stack=s) elif create_if_missing: prev = type(self)(self.context, self.name, self.t, self.env, owner_id=self.id) prev.store(backup=True) logger.debug('Created new backup stack') return prev else: return None
[docs] def update(self, newstack): ''' Compare the current stack with newstack, and where necessary create/update/delete the resources until this stack aligns with newstack. Note update of existing stack resources depends on update being implemented in the underlying resource types Update will fail if it exceeds the specified timeout. The default is 60 minutes, set in the constructor ''' updater = scheduler.TaskRunner(self.update_task, newstack) updater()
@scheduler.wrappertask
[docs] def update_task(self, newstack, action=UPDATE): if action not in (self.UPDATE, self.ROLLBACK): logger.error("Unexpected action %s passed to update!" % action) self.state_set(self.UPDATE, self.FAILED, "Invalid action %s" % action) return if self.status != self.COMPLETE: if (action == self.ROLLBACK and self.state == (self.UPDATE, self.IN_PROGRESS)): logger.debug("Starting update rollback for %s" % self.name) else: self.state_set(action, self.FAILED, 'State invalid for %s' % action) return self.state_set(self.UPDATE, self.IN_PROGRESS, 'Stack %s started' % action) oldstack = Stack(self.context, self.name, self.t, self.env) backup_stack = self._backup_stack() try: update_task = update.StackUpdate(self, newstack, backup_stack, rollback=action == self.ROLLBACK) updater = scheduler.TaskRunner(update_task) self.env = newstack.env self.parameters = newstack.parameters try: updater.start(timeout=self.timeout_secs()) yield while not updater.step(): yield finally: self.reset_dependencies() if action == self.UPDATE: reason = 'Stack successfully updated' else: reason = 'Stack rollback completed' stack_status = self.COMPLETE except scheduler.Timeout: stack_status = self.FAILED reason = 'Timed out' except exception.ResourceFailure as e: reason = str(e) stack_status = self.FAILED if action == self.UPDATE: # If rollback is enabled, we do another update, with the # existing template, so we roll back to the original state if not self.disable_rollback: yield self.update_task(oldstack, action=self.ROLLBACK) return else: logger.debug('Deleting backup stack') backup_stack.delete() self.state_set(action, stack_status, reason) # flip the template to the newstack values # Note we do this on success and failure, so the current # stack resources are stored, even if one is in a failed # state (otherwise we won't remove them on delete) self.t = newstack.t template_outputs = self.t[template.OUTPUTS] self.outputs = self.resolve_static_data(template_outputs) self.store()
[docs] def delete(self, action=DELETE): ''' Delete all of the resources, and then the stack itself. The action parameter is used to differentiate between a user initiated delete and an automatic stack rollback after a failed create, which amount to the same thing, but the states are recorded differently. ''' if action not in (self.DELETE, self.ROLLBACK): logger.error("Unexpected action %s passed to delete!" % action) self.state_set(self.DELETE, self.FAILED, "Invalid action %s" % action) return stack_status = self.COMPLETE reason = 'Stack %s completed successfully' % action.lower() self.state_set(action, self.IN_PROGRESS, 'Stack %s started' % action) backup_stack = self._backup_stack(False) if backup_stack is not None: backup_stack.delete() if backup_stack.status != backup_stack.COMPLETE: errs = backup_stack.status_reason failure = 'Error deleting backup resources: %s' % errs self.state_set(action, self.FAILED, 'Failed to %s : %s' % (action, failure)) return action_task = scheduler.DependencyTaskGroup(self.dependencies, resource.Resource.destroy, reverse=True) try: scheduler.TaskRunner(action_task)(timeout=self.timeout_secs()) except exception.ResourceFailure as ex: stack_status = self.FAILED reason = 'Resource %s failed: %s' % (action.lower(), str(ex)) except scheduler.Timeout: stack_status = self.FAILED reason = '%s timed out' % action.title() self.state_set(action, stack_status, reason) if stack_status != self.FAILED: # If we created a trust, delete it stack = db_api.stack_get(self.context, self.id) user_creds = db_api.user_creds_get(stack.user_creds_id) trust_id = user_creds.get('trust_id') if trust_id: self.clients.keystone().delete_trust(trust_id) # delete the stack db_api.stack_delete(self.context, self.id) self.id = None
[docs] def suspend(self): ''' Suspend the stack, which invokes handle_suspend for all stack resources waits for all resources to become SUSPEND_COMPLETE then declares the stack SUSPEND_COMPLETE. Note the default implementation for all resources is to do nothing other than move to SUSPEND_COMPLETE, so the resources must implement handle_suspend for this to have any effect. ''' sus_task = scheduler.TaskRunner(self.stack_task, action=self.SUSPEND, reverse=True) sus_task(timeout=self.timeout_secs())
[docs] def resume(self): ''' Resume the stack, which invokes handle_resume for all stack resources waits for all resources to become RESUME_COMPLETE then declares the stack RESUME_COMPLETE. Note the default implementation for all resources is to do nothing other than move to RESUME_COMPLETE, so the resources must implement handle_resume for this to have any effect. ''' sus_task = scheduler.TaskRunner(self.stack_task, action=self.RESUME, reverse=False) sus_task(timeout=self.timeout_secs())
[docs] def output(self, key): ''' Get the value of the specified stack output. ''' value = self.outputs[key].get('Value', '') return self.resolve_runtime_data(value)
[docs] def restart_resource(self, resource_name): ''' stop resource_name and all that depend on it start resource_name and all that depend on it ''' deps = self.dependencies[self[resource_name]] failed = False for res in reversed(deps): try: scheduler.TaskRunner(res.destroy)() except exception.ResourceFailure as ex: failed = True logger.error('delete: %s' % str(ex)) for res in deps: if not failed: try: res.state_reset() scheduler.TaskRunner(res.create)() except exception.ResourceFailure as ex: logger.exception('create') failed = True else: res.state_set(res.CREATE, res.FAILED, 'Resource restart aborted') # TODO(asalkeld) if any of this fails we Should # restart the whole stack
[docs] def get_availability_zones(self): if self._zones is None: self._zones = [ zone.zoneName for zone in self.clients.nova().availability_zones.list(detailed=False)] return self._zones
[docs] def resolve_static_data(self, snippet): return resolve_static_data(self.t, self, self.parameters, snippet)
[docs] def resolve_runtime_data(self, snippet): return resolve_runtime_data(self.t, self.resources, snippet)
[docs]def resolve_static_data(template, stack, parameters, snippet): ''' Resolve static parameters, map lookups, etc. in a template. Example: >>> from heat.common import template_format >>> template_str = '# JSON or YAML encoded template' >>> template = Template(template_format.parse(template_str)) >>> parameters = Parameters('stack', template, {'KeyName': 'my_key'}) >>> resolve_static_data(template, None, parameters, {'Ref': 'KeyName'}) 'my_key' ''' return transform(snippet, [functools.partial(template.resolve_param_refs, parameters=parameters), functools.partial(template.resolve_availability_zones, stack=stack), functools.partial(template.resolve_resource_facade, stack=stack), template.resolve_find_in_map, template.reduce_joins])
[docs]def resolve_runtime_data(template, resources, snippet): return transform(snippet, [functools.partial(template.resolve_resource_refs, resources=resources), functools.partial(template.resolve_attributes, resources=resources), template.resolve_split, template.resolve_member_list_to_map, template.resolve_select, template.resolve_joins, template.resolve_replace, template.resolve_base64])
[docs]def transform(data, transformations): ''' Apply each of the transformation functions in the supplied list to the data in turn. ''' for t in transformations: data = t(data) return data