path: root/zuul/executor/server.py

# Copyright 2014 OpenStack Foundation
#
# 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.

import collections
import json
import logging
import os
import shutil
import signal
import socket
import subprocess
import tempfile
import threading
import time
import traceback
from zuul.lib.yamlutil import yaml

import gear
from six.moves import shlex_quote

import zuul.merger.merger
import zuul.ansible
from zuul.lib import commandsocket

COMMANDS = ['stop', 'pause', 'unpause', 'graceful', 'verbose',
            'unverbose']


class Watchdog(object):
    def __init__(self, timeout, function, args):
        self.timeout = timeout
        self.function = function
        self.args = args
        self.thread = threading.Thread(target=self._run,
                                       name='executor-watchdog')
        self.thread.daemon = True
        self.timed_out = None

    def _run(self):
        while self._running and time.time() < self.end:
            time.sleep(10)
        if self._running:
            self.timed_out = True
            self.function(*self.args)
        else:
            # Only set timed_out to false if we aren't _running
            # anymore. This means that we stopped running not because
            # of a timeout but because normal execution ended.
            self.timed_out = False

    def start(self):
        self._running = True
        self.end = time.time() + self.timeout
        self.thread.start()

    def stop(self):
        self._running = False


class JobDirPlaybook(object):
    def __init__(self, root):
        self.root = root
        self.trusted = None
        self.path = None


class SshAgent(object):
    log = logging.getLogger("zuul.ExecutorServer")

    def __init__(self):
        self.env = {}
        self.ssh_agent = None

    def start(self):
        if self.ssh_agent:
            return
        with open('/dev/null', 'r+') as devnull:
            ssh_agent = subprocess.Popen(['ssh-agent'], close_fds=True,
                                         stdout=subprocess.PIPE,
                                         stderr=devnull,
                                         stdin=devnull)
        (output, _) = ssh_agent.communicate()
        output = output.decode('utf8')
        for line in output.split("\n"):
            if '=' in line:
                line = line.split(";", 1)[0]
                (key, value) = line.split('=')
                self.env[key] = value
        self.log.info('Started SSH Agent, {}'.format(self.env))

    def stop(self):
        if 'SSH_AGENT_PID' in self.env:
            try:
                os.kill(int(self.env['SSH_AGENT_PID']), signal.SIGTERM)
            except OSError:
                self.log.exception(
                    'Problem sending SIGTERM to agent {}'.format(self.env))
            self.log.info('Sent SIGTERM to SSH Agent, {}'.format(self.env))
            self.env = {}

    def add(self, key_path):
        env = os.environ.copy()
        env.update(self.env)
        key_path = os.path.expanduser(key_path)
        self.log.debug('Adding SSH Key {}'.format(key_path))
        output = ''
        try:
            output = subprocess.check_output(['ssh-add', key_path], env=env,
                                             stderr=subprocess.PIPE)
        except subprocess.CalledProcessError:
            self.log.error('ssh-add failed: {}'.format(output))
            raise
        self.log.info('Added SSH Key {}'.format(key_path))

    def remove(self, key_path):
        env = os.environ.copy()
        env.update(self.env)
        key_path = os.path.expanduser(key_path)
        self.log.debug('Removing SSH Key {}'.format(key_path))
        subprocess.check_output(['ssh-add', '-d', key_path], env=env,
                                stderr=subprocess.PIPE)
        self.log.info('Removed SSH Key {}'.format(key_path))

    def list(self):
        if 'SSH_AUTH_SOCK' not in self.env:
            return None
        env = os.environ.copy()
        env.update(self.env)
        result = []
        for line in subprocess.Popen(['ssh-add', '-L'], env=env,
                                     stdout=subprocess.PIPE).stdout:
            line = line.decode('utf8')
            if line.strip() == 'The agent has no identities.':
                break
            result.append(line.strip())
        return result


class JobDir(object):
    def __init__(self, root, keep, build_uuid):
        '''
        :param str root: Root directory for the individual job directories.
            Can be None to use the default system temp root directory.
        :param bool keep: If True, do not delete the job directory.
        :param str build_uuid: The unique build UUID. If supplied, this will
            be used as the temp job directory name. Using this will help the
            log streaming daemon find job logs.
        '''
        # root
        #   ansible
        #     trusted.cfg
        #     untrusted.cfg
        #   work
        #     src
        #     logs
        self.keep = keep
        if root:
            tmpdir = root
        else:
            tmpdir = tempfile.gettempdir()
        self.root = os.path.join(tmpdir, build_uuid)
        os.mkdir(self.root, 0o700)
        # Work
        self.work_root = os.path.join(self.root, 'work')
        os.makedirs(self.work_root)
        self.src_root = os.path.join(self.work_root, 'src')
        os.makedirs(self.src_root)
        self.log_root = os.path.join(self.work_root, 'logs')
        os.makedirs(self.log_root)
        # Ansible
        self.ansible_root = os.path.join(self.root, 'ansible')
        os.makedirs(self.ansible_root)
        self.known_hosts = os.path.join(self.ansible_root, 'known_hosts')
        self.inventory = os.path.join(self.ansible_root, 'inventory.yaml')
        self.playbooks = []  # The list of candidate playbooks
        self.playbook = None  # A pointer to the candidate we have chosen
        self.pre_playbooks = []
        self.post_playbooks = []
        self.roles = []
        self.trusted_roles_path = []
        self.untrusted_roles_path = []
        self.untrusted_config = os.path.join(
            self.ansible_root, 'untrusted.cfg')
        self.trusted_config = os.path.join(self.ansible_root, 'trusted.cfg')
        self.job_output_file = os.path.join(self.log_root, 'job-output.txt')

    def addPrePlaybook(self):
        count = len(self.pre_playbooks)
        root = os.path.join(self.ansible_root, 'pre_playbook_%i' % (count,))
        os.makedirs(root)
        playbook = JobDirPlaybook(root)
        self.pre_playbooks.append(playbook)
        return playbook

    def addPostPlaybook(self):
        count = len(self.post_playbooks)
        root = os.path.join(self.ansible_root, 'post_playbook_%i' % (count,))
        os.makedirs(root)
        playbook = JobDirPlaybook(root)
        self.post_playbooks.append(playbook)
        return playbook

    def addPlaybook(self):
        count = len(self.playbooks)
        root = os.path.join(self.ansible_root, 'playbook_%i' % (count,))
        os.makedirs(root)
        playbook = JobDirPlaybook(root)
        self.playbooks.append(playbook)
        return playbook

    def addRole(self):
        count = len(self.roles)
        root = os.path.join(self.ansible_root, 'role_%i' % (count,))
        os.makedirs(root)
        trusted = os.path.join(root, 'trusted')
        os.makedirs(trusted)
        untrusted = os.path.join(root, 'untrusted')
        os.makedirs(untrusted)
        self.roles.append(root)
        return root

    def cleanup(self):
        if not self.keep:
            shutil.rmtree(self.root)

    def __enter__(self):
        return self

    def __exit__(self, etype, value, tb):
        self.cleanup()


class UpdateTask(object):
    def __init__(self, connection_name, project_name):
        self.connection_name = connection_name
        self.project_name = project_name
        self.event = threading.Event()

    def __eq__(self, other):
        if (other and other.connection_name == self.connection_name and
            other.project_name == self.project_name):
            return True
        return False

    def wait(self):
        self.event.wait()

    def setComplete(self):
        self.event.set()


class DeduplicateQueue(object):
    def __init__(self):
        self.queue = collections.deque()
        self.condition = threading.Condition()

    def qsize(self):
        return len(self.queue)

    def put(self, item):
        # Returns the original item if added, or an equivalent item if
        # already enqueued.
        self.condition.acquire()
        ret = None
        try:
            for x in self.queue:
                if item == x:
                    ret = x
            if ret is None:
                ret = item
                self.queue.append(item)
                self.condition.notify()
        finally:
            self.condition.release()
        return ret

    def get(self):
        self.condition.acquire()
        try:
            while True:
                try:
                    ret = self.queue.popleft()
                    return ret
                except IndexError:
                    pass
                self.condition.wait()
        finally:
            self.condition.release()


def _copy_ansible_files(python_module, target_dir):
        library_path = os.path.dirname(os.path.abspath(python_module.__file__))
        for fn in os.listdir(library_path):
            if fn == "__pycache__":
                continue
            full_path = os.path.join(library_path, fn)
            if os.path.isdir(full_path):
                shutil.copytree(full_path, os.path.join(target_dir, fn))
            else:
                shutil.copy(os.path.join(library_path, fn), target_dir)


def make_inventory_dict(nodes, groups, all_vars):

    hosts = {}
    for node in nodes:
        hosts[node['name']] = node['host_vars']

    inventory = {
        'all': {
            'hosts': hosts,
            'vars': all_vars,
        }
    }

    for group in groups:
        group_hosts = {}
        for node_name in group['nodes']:
            # children is a dict with None as values because we don't have
            # and per-group variables. If we did, None would be a dict
            # with the per-group variables
            group_hosts[node_name] = None
        inventory[group['name']] = {'hosts': group_hosts}

    return inventory


class ExecutorMergeWorker(gear.TextWorker):
    def __init__(self, executor_server, *args, **kw):
        self.zuul_executor_server = executor_server
        super(ExecutorMergeWorker, self).__init__(*args, **kw)

    def handleNoop(self, packet):
        # Wait until the update queue is empty before responding
        while self.zuul_executor_server.update_queue.qsize():
            time.sleep(1)

        with self.zuul_executor_server.merger_lock:
            super(ExecutorMergeWorker, self).handleNoop(packet)


class ExecutorServer(object):
    log = logging.getLogger("zuul.ExecutorServer")

    def __init__(self, config, connections={}, jobdir_root=None,
                 keep_jobdir=False):
        self.config = config
        self.keep_jobdir = keep_jobdir
        self.jobdir_root = jobdir_root
        # TODOv3(mordred): make the executor name more unique --
        # perhaps hostname+pid.
        self.hostname = socket.gethostname()
        self.zuul_url = config.get('merger', 'zuul_url')
        self.merger_lock = threading.Lock()
        self.verbose = False
        self.command_map = dict(
            stop=self.stop,
            pause=self.pause,
            unpause=self.unpause,
            graceful=self.graceful,
            verbose=self.verboseOn,
            unverbose=self.verboseOff,
        )

        if self.config.has_option('executor', 'git_dir'):
            self.merge_root = self.config.get('executor', 'git_dir')
        else:
            self.merge_root = '/var/lib/zuul/executor-git'

        if self.config.has_option('executor', 'default_username'):
            self.default_username = self.config.get('executor',
                                                    'default_username')
        else:
            self.default_username = 'zuul'

        if self.config.has_option('merger', 'git_user_email'):
            self.merge_email = self.config.get('merger', 'git_user_email')
        else:
            self.merge_email = None

        if self.config.has_option('merger', 'git_user_name'):
            self.merge_name = self.config.get('merger', 'git_user_name')
        else:
            self.merge_name = None

        if self.config.has_option('executor', 'untrusted_wrapper'):
            untrusted_wrapper_name = self.config.get(
                'executor', 'untrusted_wrapper').strip()
        else:
            untrusted_wrapper_name = 'bubblewrap'
        self.untrusted_wrapper = connections.drivers[untrusted_wrapper_name]

        self.connections = connections
        # This merger and its git repos are used to maintain
        # up-to-date copies of all the repos that are used by jobs, as
        # well as to support the merger:cat functon to supply
        # configuration information to Zuul when it starts.
        self.merger = self._getMerger(self.merge_root)
        self.update_queue = DeduplicateQueue()

        if self.config.has_option('zuul', 'state_dir'):
            state_dir = os.path.expanduser(
                self.config.get('zuul', 'state_dir'))
        else:
            state_dir = '/var/lib/zuul'
        path = os.path.join(state_dir, 'executor.socket')
        self.command_socket = commandsocket.CommandSocket(path)
        ansible_dir = os.path.join(state_dir, 'ansible')
        self.ansible_dir = ansible_dir
        if os.path.exists(ansible_dir):
            shutil.rmtree(ansible_dir)

        zuul_dir = os.path.join(ansible_dir, 'zuul')
        plugin_dir = os.path.join(zuul_dir, 'ansible')

        os.makedirs(plugin_dir, mode=0o0755)

        self.library_dir = os.path.join(plugin_dir, 'library')
        self.action_dir = os.path.join(plugin_dir, 'action')
        self.callback_dir = os.path.join(plugin_dir, 'callback')
        self.lookup_dir = os.path.join(plugin_dir, 'lookup')

        _copy_ansible_files(zuul.ansible, plugin_dir)

        # We're copying zuul.ansible.* into a directory we are going
        # to add to pythonpath, so our plugins can "import
        # zuul.ansible".  But we're not installing all of zuul, so
        # create a __init__.py file for the stub "zuul" module.
        with open(os.path.join(zuul_dir, '__init__.py'), 'w'):
            pass

        self.job_workers = {}

    def _getMerger(self, root, logger=None):
        if root != self.merge_root:
            cache_root = self.merge_root
        else:
            cache_root = None
        return zuul.merger.merger.Merger(root, self.connections,
                                         self.merge_email, self.merge_name,
                                         cache_root, logger)

    def start(self):
        self._running = True
        self._command_running = True
        server = self.config.get('gearman', 'server')
        if self.config.has_option('gearman', 'port'):
            port = self.config.get('gearman', 'port')
        else:
            port = 4730
        if self.config.has_option('gearman', 'ssl_key'):
            ssl_key = self.config.get('gearman', 'ssl_key')
        else:
            ssl_key = None
        if self.config.has_option('gearman', 'ssl_cert'):
            ssl_cert = self.config.get('gearman', 'ssl_cert')
        else:
            ssl_cert = None
        if self.config.has_option('gearman', 'ssl_ca'):
            ssl_ca = self.config.get('gearman', 'ssl_ca')
        else:
            ssl_ca = None
        self.merger_worker = ExecutorMergeWorker(self, 'Zuul Executor Merger')
        self.merger_worker.addServer(server, port, ssl_key, ssl_cert, ssl_ca)
        self.executor_worker = gear.TextWorker('Zuul Executor Server')
        self.executor_worker.addServer(server, port, ssl_key, ssl_cert, ssl_ca)
        self.log.debug("Waiting for server")
        self.merger_worker.waitForServer()
        self.executor_worker.waitForServer()
        self.log.debug("Registering")
        self.register()

        self.log.debug("Starting command processor")
        self.command_socket.start()
        self.command_thread = threading.Thread(target=self.runCommand)
        self.command_thread.daemon = True
        self.command_thread.start()

        self.log.debug("Starting worker")
        self.update_thread = threading.Thread(target=self._updateLoop)
        self.update_thread.daemon = True
        self.update_thread.start()
        self.merger_thread = threading.Thread(target=self.run_merger)
        self.merger_thread.daemon = True
        self.merger_thread.start()
        self.executor_thread = threading.Thread(target=self.run_executor)
        self.executor_thread.daemon = True
        self.executor_thread.start()

    def register(self):
        self.executor_worker.registerFunction("executor:execute")
        self.executor_worker.registerFunction("executor:stop:%s" %
                                              self.hostname)
        self.merger_worker.registerFunction("merger:merge")
        self.merger_worker.registerFunction("merger:cat")

    def stop(self):
        self.log.debug("Stopping")
        self._running = False
        self._command_running = False
        self.command_socket.stop()
        self.update_queue.put(None)

        for job_worker in list(self.job_workers.values()):
            try:
                job_worker.stop()
            except Exception:
                self.log.exception("Exception sending stop command "
                                   "to worker:")
        self.merger_worker.shutdown()
        self.executor_worker.shutdown()
        self.log.debug("Stopped")

    def pause(self):
        # TODOv3: implement
        pass

    def unpause(self):
        # TODOv3: implement
        pass

    def graceful(self):
        # TODOv3: implement
        pass

    def verboseOn(self):
        self.verbose = True

    def verboseOff(self):
        self.verbose = False

    def join(self):
        self.update_thread.join()
        self.merger_thread.join()
        self.executor_thread.join()

    def runCommand(self):
        while self._command_running:
            try:
                command = self.command_socket.get().decode('utf8')
                if command != '_stop':
                    self.command_map[command]()
            except Exception:
                self.log.exception("Exception while processing command")

    def _updateLoop(self):
        while self._running:
            try:
                self._innerUpdateLoop()
            except:
                self.log.exception("Exception in update thread:")

    def _innerUpdateLoop(self):
        # Inside of a loop that keeps the main repositories up to date
        task = self.update_queue.get()
        if task is None:
            # We are asked to stop
            return
        with self.merger_lock:
            self.log.info("Updating repo %s/%s" % (
                task.connection_name, task.project_name))
            self.merger.updateRepo(task.connection_name, task.project_name)
            self.log.debug("Finished updating repo %s/%s" %
                           (task.connection_name, task.project_name))
        task.setComplete()

    def update(self, connection_name, project_name):
        # Update a repository in the main merger
        task = UpdateTask(connection_name, project_name)
        task = self.update_queue.put(task)
        return task

    def run_merger(self):
        self.log.debug("Starting merger listener")
        while self._running:
            try:
                job = self.merger_worker.getJob()
                try:
                    if job.name == 'merger:cat':
                        self.log.debug("Got cat job: %s" % job.unique)
                        self.cat(job)
                    elif job.name == 'merger:merge':
                        self.log.debug("Got merge job: %s" % job.unique)
                        self.merge(job)
                    else:
                        self.log.error("Unable to handle job %s" % job.name)
                        job.sendWorkFail()
                except Exception:
                    self.log.exception("Exception while running job")
                    job.sendWorkException(
                        traceback.format_exc().encode('utf8'))
            except gear.InterruptedError:
                pass
            except Exception:
                self.log.exception("Exception while getting job")

    def run_executor(self):
        self.log.debug("Starting executor listener")
        while self._running:
            try:
                job = self.executor_worker.getJob()
                try:
                    if job.name == 'executor:execute':
                        self.log.debug("Got execute job: %s" % job.unique)
                        self.executeJob(job)
                    elif job.name.startswith('executor:stop'):
                        self.log.debug("Got stop job: %s" % job.unique)
                        self.stopJob(job)
                    else:
                        self.log.error("Unable to handle job %s" % job.name)
                        job.sendWorkFail()
                except Exception:
                    self.log.exception("Exception while running job")
                    job.sendWorkException(
                        traceback.format_exc().encode('utf8'))
            except gear.InterruptedError:
                pass
            except Exception:
                self.log.exception("Exception while getting job")

    def executeJob(self, job):
        self.job_workers[job.unique] = AnsibleJob(self, job)
        self.job_workers[job.unique].run()

    def finishJob(self, unique):
        del(self.job_workers[unique])

    def stopJob(self, job):
        try:
            args = json.loads(job.arguments)
            self.log.debug("Stop job with arguments: %s" % (args,))
            unique = args['uuid']
            job_worker = self.job_workers.get(unique)
            if not job_worker:
                self.log.debug("Unable to find worker for job %s" % (unique,))
                return
            try:
                job_worker.stop()
            except Exception:
                self.log.exception("Exception sending stop command "
                                   "to worker:")
        finally:
            job.sendWorkComplete()

    def cat(self, job):
        args = json.loads(job.arguments)
        task = self.update(args['connection'], args['project'])
        task.wait()
        with self.merger_lock:
            files = self.merger.getFiles(args['connection'], args['project'],
                                         args['branch'], args['files'])
        result = dict(updated=True,
                      files=files,
                      zuul_url=self.zuul_url)
        job.sendWorkComplete(json.dumps(result))

    def merge(self, job):
        args = json.loads(job.arguments)
        with self.merger_lock:
            ret = self.merger.mergeChanges(args['items'], args.get('files'),
                                           args.get('repo_state'))
        result = dict(merged=(ret is not None),
                      zuul_url=self.zuul_url)
        if ret is None:
            result['commit'] = result['files'] = result['repo_state'] = None
        else:
            (result['commit'], result['files'], result['repo_state'],
             recent) = ret
        job.sendWorkComplete(json.dumps(result))


class AnsibleJobLogAdapter(logging.LoggerAdapter):
    def process(self, msg, kwargs):
        msg, kwargs = super(AnsibleJobLogAdapter, self).process(msg, kwargs)
        msg = '[build: %s] %s' % (kwargs['extra']['job'], msg)
        return msg, kwargs


class AnsibleJob(object):
    RESULT_NORMAL = 1
    RESULT_TIMED_OUT = 2
    RESULT_UNREACHABLE = 3
    RESULT_ABORTED = 4

    RESULT_MAP = {
        RESULT_NORMAL: 'RESULT_NORMAL',
        RESULT_TIMED_OUT: 'RESULT_TIMED_OUT',
        RESULT_UNREACHABLE: 'RESULT_UNREACHABLE',
        RESULT_ABORTED: 'RESULT_ABORTED',
    }

    def __init__(self, executor_server, job):
        logger = logging.getLogger("zuul.AnsibleJob")
        self.log = AnsibleJobLogAdapter(logger, {'job': job.unique})
        self.executor_server = executor_server
        self.job = job
        self.jobdir = None
        self.proc = None
        self.proc_lock = threading.Lock()
        self.running = False
        self.aborted = False
        self.thread = None
        self.ssh_agent = None

        if self.executor_server.config.has_option(
            'executor', 'private_key_file'):
            self.private_key_file = self.executor_server.config.get(
                'executor', 'private_key_file')
        else:
            self.private_key_file = '~/.ssh/id_rsa'
        self.ssh_agent = SshAgent()

    def run(self):
        self.ssh_agent.start()
        self.ssh_agent.add(self.private_key_file)
        self.running = True
        self.thread = threading.Thread(target=self.execute)
        self.thread.start()

    def stop(self):
        self.aborted = True
        self.abortRunningProc()
        if self.thread:
            self.thread.join()

    def execute(self):
        try:
            self.jobdir = JobDir(self.executor_server.jobdir_root,
                                 self.executor_server.keep_jobdir,
                                 str(self.job.unique))
            self._execute()
        except Exception:
            self.log.exception("Exception while executing job")
            self.job.sendWorkException(traceback.format_exc())
        finally:
            self.running = False
            try:
                self.jobdir.cleanup()
            except Exception:
                self.log.exception("Error cleaning up jobdir:")
            try:
                self.executor_server.finishJob(self.job.unique)
            except Exception:
                self.log.exception("Error finalizing job thread:")
            if self.ssh_agent:
                try:
                    self.ssh_agent.stop()
                except Exception:
                    self.log.exception("Error stopping SSH agent:")

    def _execute(self):
        self.log.debug("Job %s: beginning" % (self.job.unique,))
        self.log.debug("Job %s: args: %s" % (self.job.unique,
                                             self.job.arguments,))
        self.log.debug("Job %s: job root at %s" %
                       (self.job.unique, self.jobdir.root))
        args = json.loads(self.job.arguments)
        tasks = []
        for project in args['projects']:
            self.log.debug("Job %s: updating project %s" %
                           (self.job.unique, project))
            tasks.append(self.executor_server.update(
                project['connection'], project['name']))
        for task in tasks:
            task.wait()

        self.log.debug("Job %s: git updates complete" % (self.job.unique,))
        merger = self.executor_server._getMerger(self.jobdir.src_root,
                                                 self.log)
        repos = {}
        for project in args['projects']:
            self.log.debug("Cloning %s/%s" % (project['connection'],
                                              project['name'],))
            repo = merger.getRepo(project['connection'],
                                  project['name'])
            repos[project['canonical_name']] = repo

        merge_items = [i for i in args['items'] if i.get('refspec')]
        if merge_items:
            if not self.doMergeChanges(merger, merge_items,
                                       args['repo_state']):
                # There was a merge conflict and we have already sent
                # a work complete result, don't run any jobs
                return

        for project in args['projects']:
            repo = repos[project['canonical_name']]
            self.checkoutBranch(repo,
                                project['name'],
                                args['branch'],
                                args['override_branch'],
                                project['override_branch'],
                                project['default_branch'])

        # Delete the origin remote from each repo we set up since
        # it will not be valid within the jobs.
        for repo in repos.values():
            repo.deleteRemote('origin')

        # is the playbook in a repo that we have already prepared?
        trusted, untrusted = self.preparePlaybookRepos(args)

        self.prepareRoles(args, trusted, untrusted)

        # TODOv3: Ansible the ansible thing here.
        self.prepareAnsibleFiles(args)

        data = {
            'manager': self.executor_server.hostname,
            'url': 'https://server/job/{}/0/'.format(args['job']),
            'worker_name': 'My Worker',
        }

        self.job.sendWorkData(json.dumps(data))
        self.job.sendWorkStatus(0, 100)

        result = self.runPlaybooks(args)

        if result is None:
            self.job.sendWorkFail()
            return
        result = dict(result=result)
        self.job.sendWorkComplete(json.dumps(result))

    def doMergeChanges(self, merger, items, repo_state):
        ret = merger.mergeChanges(items, repo_state=repo_state)
        if not ret:  # merge conflict
            result = dict(result='MERGER_FAILURE')
            self.job.sendWorkComplete(json.dumps(result))
            return False
        recent = ret[3]
        for key, commit in recent.items():
            (connection, project, branch) = key
            repo = merger.getRepo(connection, project)
            repo.setRef('refs/heads/' + branch, commit)
        return True

    def checkoutBranch(self, repo, project_name, zuul_branch,
                       job_branch, project_override_branch,
                       project_default_branch):
        branches = repo.getBranches()
        if project_override_branch in branches:
            self.log.info("Checking out %s project override branch %s",
                          project_name, project_override_branch)
            repo.checkoutLocalBranch(project_override_branch)
        elif job_branch in branches:
            self.log.info("Checking out %s job branch %s",
                          project_name, job_branch)
            repo.checkoutLocalBranch(job_branch)
        elif zuul_branch and zuul_branch in branches:
            self.log.info("Checking out %s zuul branch %s",
                          project_name, zuul_branch)
            repo.checkoutLocalBranch(zuul_branch)
        elif project_default_branch in branches:
            self.log.info("Checking out %s project default branch %s",
                          project_name, project_default_branch)
            repo.checkoutLocalBranch(project_default_branch)
        else:
            raise Exception("Project %s does not have the default branch %s" %
                            (project_name, project_default_branch))

    def runPlaybooks(self, args):
        result = None

        for playbook in self.jobdir.pre_playbooks:
            # TODOv3(pabelanger): Implement pre-run timeout setting.
            pre_status, pre_code = self.runAnsiblePlaybook(
                playbook, args['timeout'])
            if pre_status != self.RESULT_NORMAL or pre_code != 0:
                # These should really never fail, so return None and have
                # zuul try again
                return result

        job_status, job_code = self.runAnsiblePlaybook(
            self.jobdir.playbook, args['timeout'])
        if job_status == self.RESULT_TIMED_OUT:
            return 'TIMED_OUT'
        if job_status == self.RESULT_ABORTED:
            return 'ABORTED'
        if job_status != self.RESULT_NORMAL:
            # The result of the job is indeterminate.  Zuul will
            # run it again.
            return result

        success = (job_code == 0)
        if success:
            result = 'SUCCESS'
        else:
            result = 'FAILURE'

        for playbook in self.jobdir.post_playbooks:
            # TODOv3(pabelanger): Implement post-run timeout setting.
            post_status, post_code = self.runAnsiblePlaybook(
                playbook, args['timeout'], success)
            if post_status != self.RESULT_NORMAL or post_code != 0:
                result = 'POST_FAILURE'
        return result

    def getHostList(self, args):
        hosts = []
        for node in args['nodes']:
            # NOTE(mordred): This assumes that the nodepool launcher
            # and the zuul executor both have similar network
            # characteristics, as the launcher will do a test for ipv6
            # viability and if so, and if the node has an ipv6
            # address, it will be the interface_ip.  force-ipv4 can be
            # set to True in the clouds.yaml for a cloud if this
            # results in the wrong thing being in interface_ip
            # TODO(jeblair): Move this notice to the docs.
            ip = node.get('interface_ip')
            host_vars = dict(
                ansible_host=ip,
                ansible_user=self.executor_server.default_username,
                nodepool=dict(
                    az=node.get('az'),
                    provider=node.get('provider'),
                    region=node.get('region')))

            host_keys = []
            for key in node.get('host_keys'):
                host_keys.append("%s %s" % (ip, key))

            hosts.append(dict(
                name=node['name'],
                host_vars=host_vars,
                host_keys=host_keys))
        return hosts

    def _blockPluginDirs(self, path):
        '''Prevent execution of playbooks or roles with plugins

        Plugins are loaded from roles and also if there is a plugin
        dir adjacent to the playbook.  Throw an error if the path
        contains a location that would cause a plugin to get loaded.

        '''
        for entry in os.listdir(path):
            if os.path.isdir(entry) and entry.endswith('_plugins'):
                raise Exception(
                    "Ansible plugin dir %s found adjacent to playbook %s in"
                    " non-trusted repo." % (entry, path))

    def findPlaybook(self, path, required=False, trusted=False):
        for ext in ['.yaml', '.yml']:
            fn = path + ext
            if os.path.exists(fn):
                if not trusted:
                    playbook_dir = os.path.dirname(os.path.abspath(fn))
                    self._blockPluginDirs(playbook_dir)
                return fn
        if required:
            raise Exception("Unable to find playbook %s" % path)
        return None

    def preparePlaybookRepos(self, args):
        trusted = untrusted = False
        for playbook in args['pre_playbooks']:
            jobdir_playbook = self.jobdir.addPrePlaybook()
            self.preparePlaybookRepo(jobdir_playbook, playbook,
                                     args, required=True)
            if playbook['trusted']:
                trusted = True
            else:
                untrusted = True

        for playbook in args['playbooks']:
            jobdir_playbook = self.jobdir.addPlaybook()
            self.preparePlaybookRepo(jobdir_playbook, playbook,
                                     args, required=False)
            if playbook['trusted']:
                trusted = True
            else:
                untrusted = True
            if jobdir_playbook.path is not None:
                self.jobdir.playbook = jobdir_playbook
                break
        if self.jobdir.playbook is None:
            raise Exception("No valid playbook found")

        for playbook in args['post_playbooks']:
            jobdir_playbook = self.jobdir.addPostPlaybook()
            self.preparePlaybookRepo(jobdir_playbook, playbook,
                                     args, required=True)
            if playbook['trusted']:
                trusted = True
            else:
                untrusted = True
        return (trusted, untrusted)

    def preparePlaybookRepo(self, jobdir_playbook, playbook, args, required):
        self.log.debug("Prepare playbook repo for %s" % (playbook,))
        # Check out the playbook repo if needed and set the path to
        # the playbook that should be run.
        jobdir_playbook.trusted = playbook['trusted']
        source = self.executor_server.connections.getSource(
            playbook['connection'])
        project = source.getProject(playbook['project'])
        if not playbook['trusted']:
            # This is a project repo, so it is safe to use the already
            # checked out version (from speculative merging) of the
            # playbook
            for i in args['items']:
                if (i['connection'] == playbook['connection'] and
                    i['project'] == playbook['project']):
                    # We already have this repo prepared
                    path = os.path.join(self.jobdir.src_root,
                                        project.canonical_hostname,
                                        project.name,
                                        playbook['path'])
                    jobdir_playbook.path = self.findPlaybook(
                        path,
                        required=required,
                        trusted=playbook['trusted'])
                    return
        # The playbook repo is either a config repo, or it isn't in
        # the stack of changes we are testing, so check out the branch
        # tip into a dedicated space.

        merger = self.executor_server._getMerger(jobdir_playbook.root,
                                                 self.log)
        merger.checkoutBranch(playbook['connection'], project.name,
                              playbook['branch'])

        path = os.path.join(jobdir_playbook.root,
                            project.canonical_hostname,
                            project.name,
                            playbook['path'])
        jobdir_playbook.path = self.findPlaybook(
            path,
            required=required,
            trusted=playbook['trusted'])

    def prepareRoles(self, args, trusted, untrusted):
        for role in args['roles']:
            if role['type'] == 'zuul':
                root = self.jobdir.addRole()
                self.prepareZuulRole(args, role, root, trusted, untrusted)

    def findRole(self, path, trusted=False):
        d = os.path.join(path, 'tasks')
        if os.path.isdir(d):
            # This is a bare role
            if not trusted:
                self._blockPluginDirs(path)
            # None signifies that the repo is a bare role
            return None
        d = os.path.join(path, 'roles')
        if os.path.isdir(d):
            # This repo has a collection of roles
            if not trusted:
                for entry in os.listdir(d):
                    self._blockPluginDirs(os.path.join(d, entry))
            return d
        # We assume the repository itself is a collection of roles
        if not trusted:
            for entry in os.listdir(path):
                self._blockPluginDirs(os.path.join(path, entry))
        return path

    def prepareZuulRole(self, args, role, root, trusted, untrusted):
        self.log.debug("Prepare zuul role for %s" % (role,))
        # Check out the role repo if needed
        source = self.executor_server.connections.getSource(
            role['connection'])
        project = source.getProject(role['project'])
        untrusted_role_repo = None
        trusted_role_repo = None
        trusted_root = os.path.join(root, 'trusted')
        untrusted_root = os.path.join(root, 'untrusted')
        name = role['target_name']

        if untrusted:
            # There is at least one untrusted playbook.  For that
            # case, use the already checked out version (from
            # speculative merging) of the role.

            for i in args['items']:
                if (i['connection'] == role['connection'] and
                    i['project'] == role['project']):
                    # We already have this repo prepared;
                    # copy it into location.

                    path = os.path.join(self.jobdir.src_root,
                                        project.canonical_hostname,
                                        project.name)
                    # The name of the symlink is the requested name of
                    # the role (which may be the repo name or may be
                    # something else; this can come into play if this
                    # is a bare role).
                    link = os.path.join(untrusted_root, name)
                    link = os.path.realpath(link)
                    if not link.startswith(os.path.realpath(untrusted_root)):
                        raise Exception("Invalid role name %s", name)
                    os.symlink(path, link)
                    untrusted_role_repo = link
                    break

        if trusted or not untrusted_role_repo:
            # There is at least one trusted playbook which will need a
            # trusted checkout of the role, or the role did not appear
            # in the dependency chain for the change (in which case,
            # there is no existing untrusted checkout of it).  Check
            # out the branch tip into a dedicated space.
            merger = self.executor_server._getMerger(trusted_root,
                                                     self.log)
            merger.checkoutBranch(role['connection'], project.name,
                                  'master')
            orig_repo_path = os.path.join(trusted_root,
                                          project.canonical_hostname,
                                          project.name)
            if name != project.name:
                # The requested name of the role is not the same as
                # the project name, so rename the git repo as the
                # requested name.  It is the only item in this
                # directory, so we don't need to worry about
                # collisions.
                target = os.path.join(trusted_root,
                                      project.canonical_hostname,
                                      name)
                target = os.path.realpath(target)
                if not target.startswith(os.path.realpath(trusted_root)):
                    raise Exception("Invalid role name %s", name)
                os.rename(orig_repo_path, target)
                trusted_role_repo = target
            else:
                trusted_role_repo = orig_repo_path

            if not untrusted_role_repo:
                # In the case that there was no untrusted checkout,
                # use the trusted checkout.
                untrusted_role_repo = trusted_role_repo
                untrusted_root = trusted_root

        if untrusted:
            untrusted_role_path = self.findRole(untrusted_role_repo,
                                                trusted=False)
            if untrusted_role_path is None:
                # In the case of a bare role, add the containing directory
                untrusted_role_path = os.path.join(untrusted_root,
                                                   project.canonical_hostname)
            self.jobdir.untrusted_roles_path.append(untrusted_role_path)

        if trusted:
            trusted_role_path = self.findRole(trusted_role_repo,
                                              trusted=True)
            if trusted_role_path is None:
                # In the case of a bare role, add the containing directory
                trusted_role_path = os.path.join(trusted_root,
                                                 project.canonical_hostname)
            self.jobdir.trusted_roles_path.append(trusted_role_path)

    def prepareAnsibleFiles(self, args):
        all_vars = dict(args['vars'])
        all_vars['zuul']['executor'] = dict(
            hostname=self.executor_server.hostname,
            src_root=self.jobdir.src_root,
            log_root=self.jobdir.log_root)

        nodes = self.getHostList(args)
        inventory = make_inventory_dict(nodes, args['groups'], all_vars)

        with open(self.jobdir.inventory, 'w') as inventory_yaml:
            inventory_yaml.write(
                yaml.safe_dump(inventory, default_flow_style=False))

        with open(self.jobdir.known_hosts, 'w') as known_hosts:
            for node in nodes:
                for key in node['host_keys']:
                    known_hosts.write('%s\n' % key)

        self.writeAnsibleConfig(self.jobdir.untrusted_config)
        self.writeAnsibleConfig(self.jobdir.trusted_config, trusted=True)

    def writeAnsibleConfig(self, config_path, trusted=False):
        with open(config_path, 'w') as config:
            config.write('[defaults]\n')
            config.write('hostfile = %s\n' % self.jobdir.inventory)
            config.write('local_tmp = %s/.ansible/local_tmp\n' %
                         self.jobdir.root)
            config.write('remote_tmp = %s/.ansible/remote_tmp\n' %
                         self.jobdir.root)
            config.write('retry_files_enabled = False\n')
            config.write('gathering = explicit\n')
            config.write('library = %s\n'
                         % self.executor_server.library_dir)
            config.write('command_warnings = False\n')
            config.write('callback_plugins = %s\n'
                         % self.executor_server.callback_dir)
            config.write('stdout_callback = zuul_stream\n')
            # bump the timeout because busy nodes may take more than
            # 10s to respond
            config.write('timeout = 30\n')
            if not trusted:
                config.write('action_plugins = %s\n'
                             % self.executor_server.action_dir)
                config.write('lookup_plugins = %s\n'
                             % self.executor_server.lookup_dir)
                roles_path = self.jobdir.untrusted_roles_path
            else:
                roles_path = self.jobdir.trusted_roles_path

            if roles_path:
                config.write('roles_path = %s\n' % ':'.join(roles_path))

            # On trusted jobs, we want to prevent the printing of args,
            # since trusted jobs might have access to secrets that they may
            # need to pass to a task or a role. On the other hand, there
            # should be no sensitive data in untrusted jobs, and printing
            # the args could be useful for debugging.
            config.write('display_args_to_stdout = %s\n' %
                         str(not trusted))

            config.write('[ssh_connection]\n')
            # NB: when setting pipelining = True, keep_remote_files
            # must be False (the default).  Otherwise it apparently
            # will override the pipelining option and effectively
            # disable it.  Pipelining has a side effect of running the
            # command without a tty (ie, without the -tt argument to
            # ssh).  We require this behavior so that if a job runs a
            # command which expects interactive input on a tty (such
            # as sudo) it does not hang.
            config.write('pipelining = True\n')
            ssh_args = "-o ControlMaster=auto -o ControlPersist=60s " \
                "-o UserKnownHostsFile=%s" % self.jobdir.known_hosts
            config.write('ssh_args = %s\n' % ssh_args)

    def _ansibleTimeout(self, msg):
        self.log.warning(msg)
        self.abortRunningProc()

    def abortRunningProc(self):
        with self.proc_lock:
            if not self.proc:
                self.log.debug("Abort: no process is running")
                return
            self.log.debug("Abort: sending kill signal to job "
                           "process group")
            try:
                pgid = os.getpgid(self.proc.pid)
                os.killpg(pgid, signal.SIGKILL)
            except Exception:
                self.log.exception("Exception while killing ansible process:")

    def runAnsible(self, cmd, timeout, trusted=False):
        env_copy = os.environ.copy()
        env_copy.update(self.ssh_agent.env)
        env_copy['LOGNAME'] = 'zuul'
        env_copy['ZUUL_JOB_OUTPUT_FILE'] = self.jobdir.job_output_file
        pythonpath = env_copy.get('PYTHONPATH')
        if pythonpath:
            pythonpath = [pythonpath]
        else:
            pythonpath = []
        pythonpath = [self.executor_server.ansible_dir] + pythonpath
        env_copy['PYTHONPATH'] = os.path.pathsep.join(pythonpath)

        if trusted:
            config_file = self.jobdir.trusted_config
            popen = subprocess.Popen
        else:
            config_file = self.jobdir.untrusted_config
            driver = self.executor_server.untrusted_wrapper
            popen = driver.getPopen(
                work_dir=self.jobdir.root,
                ansible_dir=self.executor_server.ansible_dir,
                ssh_auth_sock=env_copy.get('SSH_AUTH_SOCK'))

        env_copy['ANSIBLE_CONFIG'] = config_file

        with self.proc_lock:
            if self.aborted:
                return (self.RESULT_ABORTED, None)
            self.log.debug("Ansible command: ANSIBLE_CONFIG=%s %s",
                           config_file, " ".join(shlex_quote(c) for c in cmd))
            self.proc = popen(
                cmd,
                cwd=self.jobdir.work_root,
                stdout=subprocess.PIPE,
                stderr=subprocess.STDOUT,
                preexec_fn=os.setsid,
                env=env_copy,
            )

        ret = None
        if timeout:
            watchdog = Watchdog(timeout, self._ansibleTimeout,
                                ("Ansible timeout exceeded",))
            watchdog.start()
        try:
            for line in iter(self.proc.stdout.readline, b''):
                line = line[:1024].rstrip()
                self.log.debug("Ansible output: %s" % (line,))
            self.log.debug("Ansible output terminated")
            ret = self.proc.wait()
            self.log.debug("Ansible exit code: %s" % (ret,))
        finally:
            if timeout:
                watchdog.stop()
                self.log.debug("Stopped watchdog")

        with self.proc_lock:
            self.proc = None

        if timeout and watchdog.timed_out:
            return (self.RESULT_TIMED_OUT, None)
        if ret == 3:
            # AnsibleHostUnreachable: We had a network issue connecting to
            # our zuul-worker.
            return (self.RESULT_UNREACHABLE, None)
        elif ret == -9:
            # Received abort request.
            return (self.RESULT_ABORTED, None)

        return (self.RESULT_NORMAL, ret)

    def runAnsiblePlaybook(self, playbook, timeout, success=None):
        env_copy = os.environ.copy()
        env_copy['LOGNAME'] = 'zuul'

        if self.executor_server.verbose:
            verbose = '-vvv'
        else:
            verbose = '-v'

        cmd = ['ansible-playbook', verbose, playbook.path]

        if success is not None:
            cmd.extend(['-e', 'success=%s' % str(bool(success))])

        result, code = self.runAnsible(
            cmd=cmd, timeout=timeout, trusted=playbook.trusted)
        self.log.debug("Ansible complete, result %s code %s" % (
            self.RESULT_MAP[result], code))
        return result, code