import os import re import hashlib import oyaml as yaml import json import time import pprint from datetime import datetime, timedelta from dateutil.tz import tzutc from botocore.exceptions import ClientError from .utils import dict_merge, search_refs from .connection import BotoConnection from .jinja import JinjaEnv, read_config_file from . import __version__ from .exceptions import ParameterNotFound, ParameterIllegalValue import cfnlint.core import logging logger = logging.getLogger(__name__) class StackStatus(object): """ StackStatus stores simplified stack statuses. """ COMPLETE = "complete" FAILED = "failed" IN_PROGRESS = "in progress" PENDING = "pending" class Stack(object): def __init__(self, name, template, path, rel_path, ctx): self.stackname = name self.template = template self.path = path self.rel_path = rel_path self.ctx = ctx self.tags = {} self.parameters = {} self.options = {'Legacy': False} self.region = 'global' self.profile = '' self.onfailure = 'DELETE' self.notfication_sns = [] self.id = (self.profile, self.region, self.stackname) self.md5 = None self.mode = 'CloudBender' self.provides = template self.cfn_template = None self.cfn_parameters = [] self.cfn_data = None self.connection_manager = BotoConnection(self.profile, self.region) self.status = None self.dependencies = set() self.default_lock = None self.multi_delete = True def dump_config(self): logger.debug("".format(self.id, pprint.pformat(vars(self)))) def read_config(self, sg_config={}): """ reads stack config """ # First set various attributes based on parent stackgroup config self.tags.update(sg_config.get('tags', {})) self.parameters.update(sg_config.get('parameters', {})) self.options.update(sg_config.get('options', {})) if 'region' in sg_config: self.region = sg_config['region'] if 'profile' in sg_config: self.profile = sg_config['profile'] if 'notfication_sns' in sg_config: self.notfication_sns = sg_config['notfication_sns'] _config = read_config_file(self.path, sg_config.get('variables', {})) for p in ["region", "stackname", "template", "default_lock", "multi_delete", "provides", "onfailure", "notification_sns"]: if p in _config: setattr(self, p, _config[p]) for p in ["parameters", "tags"]: if p in _config: setattr(self, p, dict_merge(getattr(self, p), _config[p])) # Inject Artifact if not explicitly set if 'Artifact' not in self.tags: self.tags['Artifact'] = self.provides # backwards comp if 'vars' in _config: logger.warn("vars: in config is deprecated, please use options: instead") self.options = dict_merge(self.options, _config['vars']) if 'options' in _config: self.options = dict_merge(self.options, _config['options']) if 'Mode' in self.options: self.mode = self.options['Mode'] if 'dependencies' in _config: for dep in _config['dependencies']: self.dependencies.add(dep) # Some sanity checks if self.onfailure not in ["DO_NOTHING", "ROLLBACK", "DELETE"]: raise ParameterIllegalValue("onfailure must be one of DO_NOTHING | ROLLBACK | DELETE") logger.debug("Stack {} added.".format(self.id)) def render(self): """Renders the cfn jinja template for this stack""" template_metadata = { 'Template.Name': self.template, 'Template.Hash': "__HASH__", 'CloudBender.Version': __version__ } _config = {'mode': self.mode, 'options': self.options, 'metadata': template_metadata} jenv = JinjaEnv(self.ctx['artifact_paths']) jenv.globals['_config'] = _config template = jenv.get_template('{0}{1}'.format(self.template, '.yaml.jinja')) logger.info('Rendering %s', template.filename) try: self.cfn_template = template.render(_config) self.cfn_data = yaml.safe_load(self.cfn_template) except Exception as e: # In case we rendered invalid yaml this helps to debug if self.cfn_template: _output = "" for i, line in enumerate(self.cfn_template.splitlines(), start=1): _output = _output + '{}: {}\n'.format(i, line) logger.error(_output) raise e if not re.search('CloudBender::', self.cfn_template) and not re.search('Iterate:', self.cfn_template): logger.info("CloudBender not required -> removing Transform and Conglomerate parameter") self.cfn_template = self.cfn_template.replace('Transform: [CloudBender]', '') _res = """ Conglomerate: Type: String Description: Project / Namespace this stack is part of """ self.cfn_template = re.sub(_res, '', self.cfn_template) # Add Legacy FortyTwo resource to prevent AWS from replacing existing resources for NO reason ;-( include = [] search_refs(self.cfn_data, include, self.mode) if self.mode != "Piped" and len(include) and self.options['Legacy']: _res = """ FortyTwo: Type: Custom::FortyTwo Properties: ServiceToken: Fn::Sub: "arn:aws:lambda:${{AWS::Region}}:${{AWS::AccountId}}:function:FortyTwo" UpdateToken: __HASH__ Include: {}""".format(sorted(set(include))) self.cfn_template = re.sub(r'Resources:', r'Resources:' + _res + '\n', self.cfn_template) logger.info("Legacy Mode -> added Custom::FortyTwo") elif self.mode == "Piped" and len(include): _res = "" for attr in include: _res = _res + """ {0}: Type: String Description: Parameter to provide remote stack attribute {0}""".format(attr) self.cfn_template = re.sub(r'Parameters:', r'Parameters:' + _res + '\n', self.cfn_template) logger.info("Piped mode: Added parameters for remote stack references") # Re-read updated template self.cfn_data = yaml.safe_load(self.cfn_template) # Check for empty top level Parameters, Outputs and Conditions and remove for key in ['Parameters', 'Outputs', 'Conditions']: if key in self.cfn_data and not self.cfn_data[key]: del self.cfn_data[key] self.cfn_template = self.cfn_template.replace('\n' + key + ":", '') # Remove and condense multiple empty lines self.cfn_template = re.sub(r'\n\s*\n', '\n\n', self.cfn_template) self.cfn_template = re.sub(r'^\s*', '', self.cfn_template) self.cfn_template = re.sub(r'\s*$', '', self.cfn_template) # set md5 last self.md5 = hashlib.md5(self.cfn_template.encode('utf-8')).hexdigest() self.cfn_template = self.cfn_template.replace('__HASH__', self.md5) # Update internal data structures self._parse_metadata() def _parse_metadata(self): # Extract dependencies try: for dep in self.cfn_data['Metadata']['CloudBender']['Dependencies']: self.dependencies.add(dep) except KeyError: pass # Add CloudBender or FortyTwo dependencies include = [] search_refs(self.cfn_data, include, self.mode) for ref in include: if self.mode != "Piped": self.dependencies.add(ref.split('.')[0]) else: self.dependencies.add(ref.split('DoT')[0]) def write_template_file(self): if self.cfn_template: yaml_file = os.path.join(self.ctx['template_path'], self.rel_path, self.stackname + ".yaml") self._ensure_dirs('template_path') with open(yaml_file, 'w') as yaml_contents: yaml_contents.write(self.cfn_template) logger.info('Wrote %s to %s', self.template, yaml_file) if len(self.cfn_template) > 51200: logger.warning("Rendered template exceeds maximum allowed size of 51200, actual size: {} !".format(len(self.cfn_template))) else: logger.error('No cfn template rendered yet for stack {}.'.format(self.stackname)) def delete_template_file(self): yaml_file = os.path.join(self.ctx['template_path'], self.rel_path, self.stackname + ".yaml") try: os.remove(yaml_file) logger.debug('Deleted cfn template %s.', yaml_file) except OSError: pass def read_template_file(self): """ Reads rendered yaml template from disk and extracts metadata """ if not self.cfn_template: yaml_file = os.path.join(self.ctx['template_path'], self.rel_path, self.stackname + ".yaml") with open(yaml_file, 'r') as yaml_contents: self.cfn_template = yaml_contents.read() logger.debug('Read cfn template %s.', yaml_file) self.cfn_data = yaml.safe_load(self.cfn_template) self._parse_metadata() else: logger.debug('Using cached cfn template %s.', self.stackname) def validate(self): """Validates the rendered template via cfn-lint""" self.read_template_file() try: ignore_checks = self.cfn_data['Metadata']['cfnlint_ignore'] except KeyError: ignore_checks = [] # Ignore some more checks around injected parameters as we generate these if self.mode == "Piped": ignore_checks = ignore_checks + ['W2505', 'W2509', 'W2507'] # Ignore checks regarding overloaded properties if self.mode == "CloudBender": ignore_checks = ignore_checks + ['E3035', 'E3002', 'E3012', 'W2001', 'E3001'] filename = os.path.join(self.ctx['template_path'], self.rel_path, self.stackname + ".yaml") logger.info('Validating {0}'.format(filename)) lint_args = ['--template', filename] if ignore_checks: lint_args.append('--ignore-checks') lint_args = lint_args + ignore_checks logger.info('Ignoring checks: {}'.format(','.join(ignore_checks))) (args, filenames, formatter) = cfnlint.core.get_args_filenames(lint_args) (template, rules, matches) = cfnlint.core.get_template_rules(filename, args) if not matches: matches.extend(cfnlint.core.run_cli(filename, template, rules, ['us-east-1'], None)) if len(matches): for match in matches: logger.error(formatter._format(match)) else: logger.info("Passed.") def resolve_parameters(self): """ Renders parameters for the stack based on the source template and the environment configuration """ self.read_template_file() # if we run in Piped Mode, inspect all outputs of the running Conglomerate members if self.mode == "Piped": stack_outputs = {} try: stack_outputs = self._inspect_stacks(self.tags['Conglomerate']) except KeyError: pass if 'Parameters' in self.cfn_data: _errors = [] self.cfn_parameters = [] for p in self.cfn_data['Parameters']: # In Piped mode we try to resolve all Paramters first via stack_outputs if self.mode == "Piped": try: # first reverse the rename due to AWS alphanumeric restriction for parameter names _p = p.replace('DoT', '.') value = str(stack_outputs[_p]) self.cfn_parameters.append({'ParameterKey': p, 'ParameterValue': value}) logger.info('Got {} = {} from running stack'.format(p, value)) continue except KeyError: pass # Key name in config tree is: stacks..parameters. if p in self.parameters: value = str(self.parameters[p]) self.cfn_parameters.append({'ParameterKey': p, 'ParameterValue': value}) logger.info('{} {} Parameter {}={}'.format(self.region, self.stackname, p, value)) else: # If we have a Default defined in the CFN skip, as AWS will use it if 'Default' not in self.cfn_data['Parameters'][p]: _errors.append(p) if _errors: raise ParameterNotFound('Cannot find value for parameters: {0}'.format(_errors)) def write_parameter_file(self): parameter_file = os.path.join(self.ctx['parameter_path'], self.rel_path, self.stackname + ".yaml") # Render parameters as json for AWS CFN self._ensure_dirs('parameter_path') with open(parameter_file, 'w') as parameter_contents: parameter_contents.write(json.dumps(self.cfn_parameters, indent=2, separators=(',', ': '), sort_keys=True)) logger.info('Wrote json parameters for %s to %s', self.stackname, parameter_file) if not self.cfn_parameters: # Make sure there are no parameters from previous runs if os.path.isfile(parameter_file): os.remove(parameter_file) def delete_parameter_file(self): parameter_file = os.path.join(self.ctx['parameter_path'], self.rel_path, self.stackname + ".yaml") try: os.remove(parameter_file) logger.debug('Deleted parameter %s.', parameter_file) except OSError: pass def create(self): """Creates a stack """ # Prepare parameters self.resolve_parameters() self.write_parameter_file() self.read_template_file() logger.info('Creating {0} {1}'.format(self.region, self.stackname)) self.connection_manager.call( 'cloudformation', 'create_stack', {'StackName': self.stackname, 'TemplateBody': self.cfn_template, 'Parameters': self.cfn_parameters, 'OnFailure': self.onfailure, 'NotificationARNs': self.notfication_sns, 'Tags': [{"Key": str(k), "Value": str(v)} for k, v in self.tags.items()], 'Capabilities': ['CAPABILITY_IAM', 'CAPABILITY_NAMED_IAM', 'CAPABILITY_AUTO_EXPAND']}, profile=self.profile, region=self.region) return self._wait_for_completion() def update(self): """Updates an existing stack """ # Prepare parameters self.resolve_parameters() self.write_parameter_file() self.read_template_file() logger.info('Updating {0} {1}'.format(self.region, self.stackname)) try: self.connection_manager.call( 'cloudformation', 'update_stack', {'StackName': self.stackname, 'TemplateBody': self.cfn_template, 'Parameters': self.cfn_parameters, 'NotificationARNs': self.notfication_sns, 'Tags': [{"Key": str(k), "Value": str(v)} for k, v in self.tags.items()], 'Capabilities': ['CAPABILITY_IAM', 'CAPABILITY_NAMED_IAM', 'CAPABILITY_AUTO_EXPAND']}, profile=self.profile, region=self.region) except ClientError as e: if 'No updates are to be performed' in e.response['Error']['Message']: logger.info('No updates for {0}'.format(self.stackname)) return StackStatus.COMPLETE else: raise e return self._wait_for_completion() def delete(self): """Deletes a stack """ logger.info('Deleting {0} {1}'.format(self.region, self.stackname)) self.connection_manager.call( 'cloudformation', 'delete_stack', {'StackName': self.stackname}, profile=self.profile, region=self.region) return self._wait_for_completion() def create_change_set(self, change_set_name): """ Creates a Change Set with the name ``change_set_name``. """ # Prepare parameters self.resolve_parameters() self.write_parameter_file() self.read_template_file() logger.info('Creating change set {0} for stack {1}'.format(change_set_name, self.stackname)) self.connection_manager.call( 'cloudformation', 'create_change_set', {'StackName': self.stackname, 'ChangeSetName': change_set_name, 'TemplateBody': self.cfn_template, 'Parameters': self.cfn_parameters, 'Tags': [{"Key": str(k), "Value": str(v)} for k, v in self.tags.items()], 'Capabilities': ['CAPABILITY_IAM', 'CAPABILITY_NAMED_IAM']}, profile=self.profile, region=self.region) return self._wait_for_completion() def describe(self): """ Returns the a description of the stack. :returns: A stack description. """ return self.connection_manager.call( "cloudformation", "describe_stacks", {"StackName": self.stackname}, profile=self.profile, region=self.region) def get_status(self): """ Returns the stack's status. :returns: The stack's status. """ try: status = self.describe()["Stacks"][0]["StackStatus"] except ClientError as e: if e.response["Error"]["Message"].endswith("does not exist"): return None else: raise e return status def describe_events(self): """ Returns a dictionary contianing the stack events. :returns: The CloudFormation events for a stack. """ try: status = self.connection_manager.call( "cloudformation", "describe_stack_events", {"StackName": self.stackname}, profile=self.profile, region=self.region) except ClientError as e: if e.response["Error"]["Message"].endswith("does not exist"): return None else: raise e return status def _wait_for_completion(self, timeout=0): """ Waits for a stack operation to finish. Prints CloudFormation events while it waits. :param timeout: Timeout before returning :returns: The final stack status. """ def timed_out(elapsed): return elapsed >= timeout if timeout else False status = StackStatus.IN_PROGRESS self.most_recent_event_datetime = ( datetime.now(tzutc()) - timedelta(seconds=3) ) elapsed = 0 while status == StackStatus.IN_PROGRESS and not timed_out(elapsed): status = self._get_simplified_status(self.get_status()) if not status: return None self._log_new_events() time.sleep(4) elapsed += 4 return status @staticmethod def _get_simplified_status(status): """ Returns the simplified Stack Status. """ if status: if status.endswith("ROLLBACK_COMPLETE"): return StackStatus.FAILED elif status.endswith("_COMPLETE"): return StackStatus.COMPLETE elif status.endswith("_IN_PROGRESS"): return StackStatus.IN_PROGRESS elif status.endswith("_FAILED"): return StackStatus.FAILED else: return 'Unknown' def _log_new_events(self): """ Log the latest stack events while the stack is being built. """ events = self.describe_events() if events: events = events["StackEvents"] events.reverse() new_events = [ event for event in events if event["Timestamp"] > self.most_recent_event_datetime ] for event in new_events: logger.info(" ".join([ self.region, self.stackname, event["LogicalResourceId"], event["ResourceType"], event["ResourceStatus"], event.get("ResourceStatusReason", "") ])) self.most_recent_event_datetime = event["Timestamp"] def _ensure_dirs(self, path): # Ensure output dirs exist if not os.path.exists(os.path.join(self.ctx[path], self.rel_path)): os.makedirs(os.path.join(self.ctx[path], self.rel_path)) # stackoutput inspection def _inspect_stacks(self, conglomerate): # Get all stacks of the conglomertate running_stacks = self.connection_manager.call( "cloudformation", "describe_stacks", profile=self.profile, region=self.region) stacks = [] for stack in running_stacks['Stacks']: for tag in stack['Tags']: if tag['Key'] == 'Conglomerate' and tag['Value'] == conglomerate: stacks.append(stack) break # Gather stack outputs, use Tag['Artifact'] as name space: Artifact.OutputName, same as FortyTwo stack_outputs = {} for stack in stacks: # If stack has an Artifact Tag put resources into the namespace Artifact.Resource artifact = None for tag in stack['Tags']: if tag['Key'] == 'Artifact': artifact = tag['Value'] if artifact: key_prefix = "{}.".format(artifact) else: key_prefix = "" try: for output in stack['Outputs']: # Gather all outputs of the stack into one dimensional key=value structure stack_outputs[key_prefix + output['OutputKey']] = output['OutputValue'] except KeyError: pass # Add outputs from stacks into the data for jinja under StackOutput return stack_outputs