ceph/qa/tasks/vstart_runner.py

"""
vstart_runner: override Filesystem and Mount interfaces to run a CephFSTestCase against a vstart
ceph instance instead of a packaged/installed cluster.  Use this to turn around test cases
quickly during development.

Simple usage (assuming teuthology and ceph checked out in ~/git):

    # Activate the teuthology virtualenv
    source ~/git/teuthology/virtualenv/bin/activate
    # Go into your ceph build directory
    cd ~/git/ceph/build
    # Invoke a test using this script
    python ~/git/ceph/qa/tasks/vstart_runner.py --create tasks.cephfs.test_data_scan

Alternative usage:

    # Alternatively, if you use different paths, specify them as follows:
    LD_LIBRARY_PATH=`pwd`/lib PYTHONPATH=~/git/teuthology:~/git/ceph/qa:`pwd`/../src/pybind:`pwd`/lib/cython_modules/lib.2 python ~/git/ceph/qa/tasks/vstart_runner.py

    # If you wish to drop to a python shell on failures, use --interactive:
    python ~/git/ceph/qa/tasks/vstart_runner.py --interactive

    # If you wish to run a named test case, pass it as an argument:
    python ~/git/ceph/qa/tasks/vstart_runner.py tasks.cephfs.test_data_scan

"""

from StringIO import StringIO
from collections import defaultdict
import getpass
import signal
import tempfile
import threading
import datetime
import shutil
import re
import os
import time
import json
import sys
import errno
from unittest import suite, loader
import unittest
import platform
from teuthology.orchestra.run import Raw, quote
from teuthology.orchestra.daemon import DaemonGroup
from teuthology.config import config as teuth_config

import logging

log = logging.getLogger(__name__)

handler = logging.FileHandler("./vstart_runner.log")
formatter = logging.Formatter(
    fmt=u'%(asctime)s.%(msecs)03d %(levelname)s:%(name)s:%(message)s',
    datefmt='%Y-%m-%dT%H:%M:%S')
handler.setFormatter(formatter)
log.addHandler(handler)
log.setLevel(logging.INFO)


def respawn_in_path(lib_path, python_paths):
    execv_cmd = ['python']
    if platform.system() == "Darwin":
        lib_path_var = "DYLD_LIBRARY_PATH"
    else:
        lib_path_var = "LD_LIBRARY_PATH"

    py_binary = os.environ.get("PYTHON", "python")

    if lib_path_var in os.environ:
        if lib_path not in os.environ[lib_path_var]:
            os.environ[lib_path_var] += ':' + lib_path
            os.execvp(py_binary, execv_cmd + sys.argv)
    else:
        os.environ[lib_path_var] = lib_path
        os.execvp(py_binary, execv_cmd + sys.argv)

    for p in python_paths:
        sys.path.insert(0, p)


# Let's use some sensible defaults
if os.path.exists("./CMakeCache.txt") and os.path.exists("./bin"):

    # A list of candidate paths for each package we need
    guesses = [
        ["~/git/teuthology", "~/scm/teuthology", "~/teuthology"],
        ["lib/cython_modules/lib.2"],
        ["../src/pybind"],
    ]

    python_paths = []

    # Up one level so that "tasks.foo.bar" imports work
    python_paths.append(os.path.abspath(
        os.path.join(os.path.dirname(os.path.realpath(__file__)), "..")
    ))

    for package_guesses in guesses:
        for g in package_guesses:
            g_exp = os.path.abspath(os.path.expanduser(g))
            if os.path.exists(g_exp):
                python_paths.append(g_exp)

    ld_path = os.path.join(os.getcwd(), "lib/")
    print "Using guessed paths {0} {1}".format(ld_path, python_paths)
    respawn_in_path(ld_path, python_paths)


try:
    from teuthology.exceptions import CommandFailedError
    from tasks.ceph_manager import CephManager
    from tasks.cephfs.fuse_mount import FuseMount
    from tasks.cephfs.filesystem import Filesystem, MDSCluster, CephCluster
    from mgr.mgr_test_case import MgrCluster
    from teuthology.contextutil import MaxWhileTries
    from teuthology.task import interactive
except ImportError:
    sys.stderr.write("***\nError importing packages, have you activated your teuthology virtualenv "
                     "and set PYTHONPATH to point to teuthology and ceph-qa-suite?\n***\n\n")
    raise

# Must import after teuthology because of gevent monkey patching
import subprocess

if os.path.exists("./CMakeCache.txt"):
    # Running in build dir of a cmake build
    BIN_PREFIX = "./bin/"
    SRC_PREFIX = "../src"
else:
    # Running in src/ of an autotools build
    BIN_PREFIX = "./"
    SRC_PREFIX = "./"


class LocalRemoteProcess(object):
    def __init__(self, args, subproc, check_status, stdout, stderr):
        self.args = args
        self.subproc = subproc
        if stdout is None:
            self.stdout = StringIO()
        else:
            self.stdout = stdout

        if stderr is None:
            self.stderr = StringIO()
        else:
            self.stderr = stderr

        self.check_status = check_status
        self.exitstatus = self.returncode = None

    def wait(self):
        if self.finished:
            # Avoid calling communicate() on a dead process because it'll
            # give you stick about std* already being closed
            if self.exitstatus != 0:
                raise CommandFailedError(self.args, self.exitstatus)
            else:
                return

        out, err = self.subproc.communicate()
        self.stdout.write(out)
        self.stderr.write(err)

        self.exitstatus = self.returncode = self.subproc.returncode

        if self.exitstatus != 0:
            sys.stderr.write(out)
            sys.stderr.write(err)

        if self.check_status and self.exitstatus != 0:
            raise CommandFailedError(self.args, self.exitstatus)

    @property
    def finished(self):
        if self.exitstatus is not None:
            return True

        if self.subproc.poll() is not None:
            out, err = self.subproc.communicate()
            self.stdout.write(out)
            self.stderr.write(err)
            self.exitstatus = self.returncode = self.subproc.returncode
            return True
        else:
            return False

    def kill(self):
        log.info("kill ")
        if self.subproc.pid and not self.finished:
            log.info("kill: killing pid {0} ({1})".format(
                self.subproc.pid, self.args))
            safe_kill(self.subproc.pid)
        else:
            log.info("kill: already terminated ({0})".format(self.args))

    @property
    def stdin(self):
        class FakeStdIn(object):
            def __init__(self, mount_daemon):
                self.mount_daemon = mount_daemon

            def close(self):
                self.mount_daemon.kill()

        return FakeStdIn(self)


class LocalRemote(object):
    """
    Amusingly named class to present the teuthology RemoteProcess interface when we are really
    running things locally for vstart

    Run this inside your src/ dir!
    """

    def __init__(self):
        self.name = "local"
        self.hostname = "localhost"
        self.user = getpass.getuser()

    def get_file(self, path, sudo, dest_dir):
        tmpfile = tempfile.NamedTemporaryFile(delete=False).name
        shutil.copy(path, tmpfile)
        return tmpfile

    def put_file(self, src, dst, sudo=False):
        shutil.copy(src, dst)

    def run(self, args, check_status=True, wait=True,
            stdout=None, stderr=None, cwd=None, stdin=None,
            logger=None, label=None, env=None):
        log.info("run args={0}".format(args))

        # We don't need no stinkin' sudo
        args = [a for a in args if a != "sudo"]

        # We have to use shell=True if any run.Raw was present, e.g. &&
        shell = any([a for a in args if isinstance(a, Raw)])

        if shell:
            filtered = []
            i = 0
            while i < len(args):
                if args[i] == 'adjust-ulimits':
                    i += 1
                elif args[i] == 'ceph-coverage':
                    i += 2
                elif args[i] == 'timeout':
                    i += 2
                else:
                    filtered.append(args[i])
                    i += 1

            args = quote(filtered)
            log.info("Running {0}".format(args))

            subproc = subprocess.Popen(args,
                                       stdout=subprocess.PIPE,
                                       stderr=subprocess.PIPE,
                                       stdin=subprocess.PIPE,
                                       cwd=cwd,
                                       shell=True)
        else:
            log.info("Running {0}".format(args))

            for arg in args:
                if not isinstance(arg, basestring):
                    raise RuntimeError("Oops, can't handle arg {0} type {1}".format(
                        arg, arg.__class__
                    ))

            subproc = subprocess.Popen(args,
                                       stdout=subprocess.PIPE,
                                       stderr=subprocess.PIPE,
                                       stdin=subprocess.PIPE,
                                       cwd=cwd,
                                       env=env)

        if stdin:
            if not isinstance(stdin, basestring):
                raise RuntimeError("Can't handle non-string stdins on a vstart cluster")

            # Hack: writing to stdin is not deadlock-safe, but it "always" works
            # as long as the input buffer is "small"
            subproc.stdin.write(stdin)

        proc = LocalRemoteProcess(
            args, subproc, check_status,
            stdout, stderr
        )

        if wait:
            proc.wait()

        return proc


class LocalDaemon(object):
    def __init__(self, daemon_type, daemon_id):
        self.daemon_type = daemon_type
        self.daemon_id = daemon_id
        self.controller = LocalRemote()
        self.proc = None

    @property
    def remote(self):
        return LocalRemote()

    def running(self):
        return self._get_pid() is not None

    def _get_pid(self):
        """
        Return PID as an integer or None if not found
        """
        ps_txt = self.controller.run(
            args=["ps", "ww", "-u"+str(os.getuid())]
        ).stdout.getvalue().strip()
        lines = ps_txt.split("\n")[1:]

        for line in lines:
            if line.find("ceph-{0} -i {1}".format(self.daemon_type, self.daemon_id)) != -1:
                log.info("Found ps line for daemon: {0}".format(line))
                return int(line.split()[0])
        log.info("No match for {0} {1}: {2}".format(
            self.daemon_type, self.daemon_id, ps_txt
            ))
        return None

    def wait(self, timeout):
        waited = 0
        while self._get_pid() is not None:
            if waited > timeout:
                raise MaxWhileTries("Timed out waiting for daemon {0}.{1}".format(self.daemon_type, self.daemon_id))
            time.sleep(1)
            waited += 1

    def stop(self, timeout=300):
        if not self.running():
            log.error('tried to stop a non-running daemon')
            return

        pid = self._get_pid()
        log.info("Killing PID {0} for {1}.{2}".format(pid, self.daemon_type, self.daemon_id))
        os.kill(pid, signal.SIGKILL)

        waited = 0
        while pid is not None:
            new_pid = self._get_pid()
            if new_pid is not None and new_pid != pid:
                log.info("Killing new PID {0}".format(new_pid))
                pid = new_pid
                os.kill(pid, signal.SIGKILL)

            if new_pid is None:
                break
            else:
                if waited > timeout:
                    raise MaxWhileTries(
                        "Timed out waiting for daemon {0}.{1}".format(
                            self.daemon_type, self.daemon_id))
                time.sleep(1)
                waited += 1

        self.wait(timeout=timeout)

    def restart(self):
        if self._get_pid() is not None:
            self.stop()

        self.proc = self.controller.run([os.path.join(BIN_PREFIX, "./ceph-{0}".format(self.daemon_type)), "-i", self.daemon_id])


def safe_kill(pid):
    """
    os.kill annoyingly raises exception if process already dead.  Ignore it.
    """
    try:
        return os.kill(pid, signal.SIGKILL)
    except OSError as e:
        if e.errno == errno.ESRCH:
            # Raced with process termination
            pass
        else:
            raise


class LocalFuseMount(FuseMount):
    def __init__(self, test_dir, client_id):
        super(LocalFuseMount, self).__init__(None, test_dir, client_id, LocalRemote())

    @property
    def config_path(self):
        return "./ceph.conf"

    def get_keyring_path(self):
        # This is going to end up in a config file, so use an absolute path
        # to avoid assumptions about daemons' pwd
        return os.path.abspath("./client.{0}.keyring".format(self.client_id))

    def run_shell(self, args, wait=True):
        # FIXME maybe should add a pwd arg to teuthology.orchestra so that
        # the "cd foo && bar" shenanigans isn't needed to begin with and
        # then we wouldn't have to special case this
        return self.client_remote.run(
            args, wait=wait, cwd=self.mountpoint
        )

    @property
    def _prefix(self):
        return BIN_PREFIX

    def _asok_path(self):
        # In teuthology, the asok is named after the PID of the ceph-fuse process, because it's
        # run foreground.  When running it daemonized however, the asok is named after
        # the PID of the launching process, not the long running ceph-fuse process.  Therefore
        # we need to give an exact path here as the logic for checking /proc/ for which
        # asok is alive does not work.

        # Load the asok path from ceph.conf as vstart.sh now puts admin sockets
        # in a tmpdir. All of the paths are the same, so no need to select
        # based off of the service type.
        d = "./out"
        with open(self.config_path) as f:
            for line in f:
                asok_conf = re.search("^\s*admin\s+socket\s*=\s*(.*?)[^/]+$", line)
                if asok_conf:
                    d = asok_conf.groups(1)[0]
                    break
        path = "{0}/client.{1}.{2}.asok".format(d, self.client_id, self.fuse_daemon.subproc.pid)
        log.info("I think my launching pid was {0}".format(self.fuse_daemon.subproc.pid))
        return path

    def umount(self):
        if self.is_mounted():
            super(LocalFuseMount, self).umount()

    def mount(self, mount_path=None, mount_fs_name=None):
        self.client_remote.run(
            args=[
                'mkdir',
                '--',
                self.mountpoint,
            ],
        )

        def list_connections():
            self.client_remote.run(
                args=["mount", "-t", "fusectl", "/sys/fs/fuse/connections", "/sys/fs/fuse/connections"],
                check_status=False
            )
            p = self.client_remote.run(
                args=["ls", "/sys/fs/fuse/connections"],
                check_status=False
            )
            if p.exitstatus != 0:
                log.warn("ls conns failed with {0}, assuming none".format(p.exitstatus))
                return []

            ls_str = p.stdout.getvalue().strip()
            if ls_str:
                return [int(n) for n in ls_str.split("\n")]
            else:
                return []

        # Before starting ceph-fuse process, note the contents of
        # /sys/fs/fuse/connections
        pre_mount_conns = list_connections()
        log.info("Pre-mount connections: {0}".format(pre_mount_conns))

        prefix = [os.path.join(BIN_PREFIX, "ceph-fuse")]
        if os.getuid() != 0:
            prefix += ["--client-die-on-failed-remount=false"]

        if mount_path is not None:
            prefix += ["--client_mountpoint={0}".format(mount_path)]

        if mount_fs_name is not None:
            prefix += ["--client_mds_namespace={0}".format(mount_fs_name)]

        self.fuse_daemon = self.client_remote.run(args=
                                            prefix + [
                                                "-f",
                                                "--name",
                                                "client.{0}".format(self.client_id),
                                                self.mountpoint
                                            ], wait=False)

        log.info("Mounting client.{0} with pid {1}".format(self.client_id, self.fuse_daemon.subproc.pid))

        # Wait for the connection reference to appear in /sys
        waited = 0
        post_mount_conns = list_connections()
        while len(post_mount_conns) <= len(pre_mount_conns):
            if self.fuse_daemon.finished:
                # Did mount fail?  Raise the CommandFailedError instead of
                # hitting the "failed to populate /sys/" timeout
                self.fuse_daemon.wait()
            time.sleep(1)
            waited += 1
            if waited > 30:
                raise RuntimeError("Fuse mount failed to populate /sys/ after {0} seconds".format(
                    waited
                ))
            post_mount_conns = list_connections()

        log.info("Post-mount connections: {0}".format(post_mount_conns))

        # Record our fuse connection number so that we can use it when
        # forcing an unmount
        new_conns = list(set(post_mount_conns) - set(pre_mount_conns))
        if len(new_conns) == 0:
            raise RuntimeError("New fuse connection directory not found ({0})".format(new_conns))
        elif len(new_conns) > 1:
            raise RuntimeError("Unexpectedly numerous fuse connections {0}".format(new_conns))
        else:
            self._fuse_conn = new_conns[0]

    def _run_python(self, pyscript):
        """
        Override this to remove the daemon-helper prefix that is used otherwise
        to make the process killable.
        """
        return self.client_remote.run(args=[
            'python', '-c', pyscript
        ], wait=False)


class LocalCephManager(CephManager):
    def __init__(self):
        # Deliberately skip parent init, only inheriting from it to get
        # util methods like osd_dump that sit on top of raw_cluster_cmd
        self.controller = LocalRemote()

        # A minority of CephManager fns actually bother locking for when
        # certain teuthology tests want to run tasks in parallel
        self.lock = threading.RLock()

        self.log = lambda x: log.info(x)

    def find_remote(self, daemon_type, daemon_id):
        """
        daemon_type like 'mds', 'osd'
        daemon_id like 'a', '0'
        """
        return LocalRemote()

    def run_ceph_w(self):
        proc = self.controller.run([os.path.join(BIN_PREFIX, "ceph"), "-w"], wait=False, stdout=StringIO())
        return proc

    def raw_cluster_cmd(self, *args):
        """
        args like ["osd", "dump"}
        return stdout string
        """
        proc = self.controller.run([os.path.join(BIN_PREFIX, "ceph")] + list(args))
        return proc.stdout.getvalue()

    def raw_cluster_cmd_result(self, *args):
        """
        like raw_cluster_cmd but don't check status, just return rc
        """
        proc = self.controller.run([os.path.join(BIN_PREFIX, "ceph")] + list(args), check_status=False)
        return proc.exitstatus

    def admin_socket(self, daemon_type, daemon_id, command, check_status=True):
        return self.controller.run(
            args=[os.path.join(BIN_PREFIX, "ceph"), "daemon", "{0}.{1}".format(daemon_type, daemon_id)] + command, check_status=check_status
        )

    # FIXME: copypasta
    def get_mds_status(self, mds):
        """
        Run cluster commands for the mds in order to get mds information
        """
        out = self.raw_cluster_cmd('mds', 'dump', '--format=json')
        j = json.loads(' '.join(out.splitlines()[1:]))
        # collate; for dup ids, larger gid wins.
        for info in j['info'].itervalues():
            if info['name'] == mds:
                return info
        return None

    # FIXME: copypasta
    def get_mds_status_by_rank(self, rank):
        """
        Run cluster commands for the mds in order to get mds information
        check rank.
        """
        j = self.get_mds_status_all()
        # collate; for dup ids, larger gid wins.
        for info in j['info'].itervalues():
            if info['rank'] == rank:
                return info
        return None

    def get_mds_status_all(self):
        """
        Run cluster command to extract all the mds status.
        """
        out = self.raw_cluster_cmd('mds', 'dump', '--format=json')
        j = json.loads(' '.join(out.splitlines()[1:]))
        return j


class LocalCephCluster(CephCluster):
    def __init__(self, ctx):
        # Deliberately skip calling parent constructor
        self._ctx = ctx
        self.mon_manager = LocalCephManager()
        self._conf = defaultdict(dict)

    @property
    def admin_remote(self):
        return LocalRemote()

    def get_config(self, key, service_type=None):
        if service_type is None:
            service_type = 'mon'

        # FIXME hardcoded vstart service IDs
        service_id = {
            'mon': 'a',
            'mds': 'a',
            'osd': '0'
        }[service_type]

        return self.json_asok(['config', 'get', key], service_type, service_id)[key]

    def _write_conf(self):
        # In teuthology, we have the honour of writing the entire ceph.conf, but
        # in vstart land it has mostly already been written and we need to carefully
        # append to it.
        conf_path = "./ceph.conf"
        banner = "\n#LOCAL_TEST\n"
        existing_str = open(conf_path).read()

        if banner in existing_str:
            existing_str = existing_str[0:existing_str.find(banner)]

        existing_str += banner

        for subsys, kvs in self._conf.items():
            existing_str += "\n[{0}]\n".format(subsys)
            for key, val in kvs.items():
                # Comment out existing instance if it exists
                log.info("Searching for existing instance {0}/{1}".format(
                    key, subsys
                ))
                existing_section = re.search("^\[{0}\]$([\n]|[^\[])+".format(
                    subsys
                ), existing_str, re.MULTILINE)

                if existing_section:
                    section_str = existing_str[existing_section.start():existing_section.end()]
                    existing_val = re.search("^\s*[^#]({0}) =".format(key), section_str, re.MULTILINE)
                    if existing_val:
                        start = existing_section.start() + existing_val.start(1)
                        log.info("Found string to replace at {0}".format(
                            start
                        ))
                        existing_str = existing_str[0:start] + "#" + existing_str[start:]

                existing_str += "{0} = {1}\n".format(key, val)

        open(conf_path, "w").write(existing_str)

    def set_ceph_conf(self, subsys, key, value):
        self._conf[subsys][key] = value
        self._write_conf()

    def clear_ceph_conf(self, subsys, key):
        del self._conf[subsys][key]
        self._write_conf()


class LocalMDSCluster(LocalCephCluster, MDSCluster):
    def __init__(self, ctx):
        super(LocalMDSCluster, self).__init__(ctx)

        self.mds_ids = ctx.daemons.daemons['mds'].keys()
        self.mds_daemons = dict([(id_, LocalDaemon("mds", id_)) for id_ in self.mds_ids])

    def clear_firewall(self):
        # FIXME: unimplemented
        pass

    def newfs(self, name='cephfs', create=True):
        return LocalFilesystem(self._ctx, name=name, create=create)


class LocalMgrCluster(LocalCephCluster, MgrCluster):
    def __init__(self, ctx):
        super(LocalMgrCluster, self).__init__(ctx)

        self.mgr_ids = ctx.daemons.daemons['mgr'].keys()
        self.mgr_daemons = dict([(id_, LocalDaemon("mgr", id_)) for id_ in self.mgr_ids])


class LocalFilesystem(Filesystem, LocalMDSCluster):
    def __init__(self, ctx, fscid=None, name='cephfs', create=False):
        # Deliberately skip calling parent constructor
        self._ctx = ctx

        self.id = None
        self.name = None
        self.metadata_pool_name = None
        self.metadata_overlay = False
        self.data_pool_name = None
        self.data_pools = None

        # Hack: cheeky inspection of ceph.conf to see what MDSs exist
        self.mds_ids = set()
        for line in open("ceph.conf").readlines():
            match = re.match("^\[mds\.(.+)\]$", line)
            if match:
                self.mds_ids.add(match.group(1))

        if not self.mds_ids:
            raise RuntimeError("No MDSs found in ceph.conf!")

        self.mds_ids = list(self.mds_ids)

        log.info("Discovered MDS IDs: {0}".format(self.mds_ids))

        self.mon_manager = LocalCephManager()

        self.mds_daemons = dict([(id_, LocalDaemon("mds", id_)) for id_ in self.mds_ids])

        self.client_remote = LocalRemote()

        self._conf = defaultdict(dict)

        if name is not None:
            if fscid is not None:
                raise RuntimeError("cannot specify fscid when creating fs")
            if create and not self.legacy_configured():
                self.create()
        else:
            if fscid is not None:
                self.id = fscid
                self.getinfo(refresh=True)

        # Stash a reference to the first created filesystem on ctx, so
        # that if someone drops to the interactive shell they can easily
        # poke our methods.
        if not hasattr(self._ctx, "filesystem"):
            self._ctx.filesystem = self

    @property
    def _prefix(self):
        return BIN_PREFIX

    def set_clients_block(self, blocked, mds_id=None):
        raise NotImplementedError()

    def get_pgs_per_fs_pool(self):
        # FIXME: assuming there are 3 OSDs
        return 3 * int(self.get_config('mon_pg_warn_min_per_osd'))


class InteractiveFailureResult(unittest.TextTestResult):
    """
    Specialization that implements interactive-on-error style
    behavior.
    """
    def addFailure(self, test, err):
        super(InteractiveFailureResult, self).addFailure(test, err)
        log.error(self._exc_info_to_string(err, test))
        log.error("Failure in test '{0}', going interactive".format(
            self.getDescription(test)
        ))
        interactive.task(ctx=None, config=None)

    def addError(self, test, err):
        super(InteractiveFailureResult, self).addError(test, err)
        log.error(self._exc_info_to_string(err, test))
        log.error("Error in test '{0}', going interactive".format(
            self.getDescription(test)
        ))
        interactive.task(ctx=None, config=None)


def enumerate_methods(s):
    log.info("e: {0}".format(s))
    for t in s._tests:
        if isinstance(t, suite.BaseTestSuite):
            for sub in enumerate_methods(t):
                yield sub
        else:
            yield s, t


def load_tests(modules, loader):
    if modules:
        log.info("Executing modules: {0}".format(modules))
        module_suites = []
        for mod_name in modules:
            # Test names like cephfs.test_auto_repair
            module_suites.append(loader.loadTestsFromName(mod_name))
        log.info("Loaded: {0}".format(list(module_suites)))
        return suite.TestSuite(module_suites)
    else:
        log.info("Executing all cephfs tests")
        return loader.discover(
            os.path.join(os.path.dirname(os.path.abspath(__file__)), "cephfs")
        )


def scan_tests(modules):
    overall_suite = load_tests(modules, loader.TestLoader())

    max_required_mds = 0
    max_required_clients = 0
    max_required_mgr = 0

    for suite, case in enumerate_methods(overall_suite):
        max_required_mds = max(max_required_mds,
                               getattr(case, "MDSS_REQUIRED", 0))
        max_required_clients = max(max_required_clients,
                               getattr(case, "CLIENTS_REQUIRED", 0))
        max_required_mgr = max(max_required_mgr,
                               getattr(case, "MGRS_REQUIRED", 0))

    return max_required_mds, max_required_clients, max_required_mgr


class LocalCluster(object):
    def __init__(self, rolename="placeholder"):
        self.remotes = {
            LocalRemote(): [rolename]
        }

    def only(self, requested):
        return self.__class__(rolename=requested)


class LocalContext(object):
    def __init__(self):
        self.config = {}
        self.teuthology_config = teuth_config
        self.cluster = LocalCluster()
        self.daemons = DaemonGroup()

        # Shove some LocalDaemons into the ctx.daemons DaemonGroup instance so that any
        # tests that want to look these up via ctx can do so.
        # Inspect ceph.conf to see what roles exist
        for conf_line in open("ceph.conf").readlines():
            for svc_type in ["mon", "osd", "mds", "mgr"]:
                if svc_type not in self.daemons.daemons:
                    self.daemons.daemons[svc_type] = {}
                match = re.match("^\[{0}\.(.+)\]$".format(svc_type), conf_line)
                if match:
                    svc_id = match.group(1)
                    self.daemons.daemons[svc_type][svc_id] = LocalDaemon(svc_type, svc_id)

    def __del__(self):
        shutil.rmtree(self.teuthology_config['test_path'])


def exec_test():
    # Parse arguments
    interactive_on_error = False
    create_cluster = False

    args = sys.argv[1:]
    flags = [a for a in args if a.startswith("-")]
    modules = [a for a in args if not a.startswith("-")]
    for f in flags:
        if f == "--interactive":
            interactive_on_error = True
        elif f == "--create":
            create_cluster = True
        else:
            log.error("Unknown option '{0}'".format(f))
            sys.exit(-1)

    # Help developers by stopping up-front if their tree isn't built enough for all the
    # tools that the tests might want to use (add more here if needed)
    require_binaries = ["ceph-dencoder", "cephfs-journal-tool", "cephfs-data-scan",
                        "cephfs-table-tool", "ceph-fuse", "rados"]
    missing_binaries = [b for b in require_binaries if not os.path.exists(os.path.join(BIN_PREFIX, b))]
    if missing_binaries:
        log.error("Some ceph binaries missing, please build them: {0}".format(" ".join(missing_binaries)))
        sys.exit(-1)

    max_required_mds, max_required_clients, max_required_mgr = scan_tests(modules)

    remote = LocalRemote()

    # Tolerate no MDSs or clients running at start
    ps_txt = remote.run(
        args=["ps", "-u"+str(os.getuid())]
    ).stdout.getvalue().strip()
    lines = ps_txt.split("\n")[1:]
    for line in lines:
        if 'ceph-fuse' in line or 'ceph-mds' in line:
            pid = int(line.split()[0])
            log.warn("Killing stray process {0}".format(line))
            os.kill(pid, signal.SIGKILL)

    # Fire up the Ceph cluster if the user requested it
    if create_cluster:
        log.info("Creating cluster with {0} MDS daemons".format(
            max_required_mds))
        remote.run([os.path.join(SRC_PREFIX, "stop.sh")], check_status=False)
        remote.run(["rm", "-rf", "./out"])
        remote.run(["rm", "-rf", "./dev"])
        vstart_env = os.environ.copy()
        vstart_env["FS"] = "0"
        vstart_env["MDS"] = max_required_mds.__str__()
        vstart_env["OSD"] = "1"
        vstart_env["MGR"] = max(max_required_mgr, 1).__str__()

        remote.run([os.path.join(SRC_PREFIX, "vstart.sh"), "-n", "-d", "--nolockdep"],
                   env=vstart_env)

        # Wait for OSD to come up so that subsequent injectargs etc will
        # definitely succeed
        LocalCephCluster(LocalContext()).mon_manager.wait_for_all_osds_up(timeout=30)

    # List of client mounts, sufficient to run the selected tests
    clients = [i.__str__() for i in range(0, max_required_clients)]

    test_dir = tempfile.mkdtemp()
    teuth_config['test_path'] = test_dir

    # Construct Mount classes
    mounts = []
    for client_id in clients:
        # Populate client keyring (it sucks to use client.admin for test clients
        # because it's awkward to find the logs later)
        client_name = "client.{0}".format(client_id)

        if client_name not in open("./keyring").read():
            p = remote.run(args=[os.path.join(BIN_PREFIX, "ceph"), "auth", "get-or-create", client_name,
                                 "osd", "allow rw",
                                 "mds", "allow",
                                 "mon", "allow r"])

            open("./keyring", "a").write(p.stdout.getvalue())

        mount = LocalFuseMount(test_dir, client_id)
        mounts.append(mount)
        if mount.is_mounted():
            log.warn("unmounting {0}".format(mount.mountpoint))
            mount.umount_wait()
        else:
            if os.path.exists(mount.mountpoint):
                os.rmdir(mount.mountpoint)

    ctx = LocalContext()
    ceph_cluster = LocalCephCluster(ctx)
    mds_cluster = LocalMDSCluster(ctx)
    mgr_cluster = LocalMgrCluster(ctx)

    from tasks.cephfs_test_runner import DecoratingLoader

    class LogStream(object):
        def __init__(self):
            self.buffer = ""

        def write(self, data):
            self.buffer += data
            if "\n" in self.buffer:
                lines = self.buffer.split("\n")
                for line in lines[:-1]:
                    pass
                    # sys.stderr.write(line + "\n")
                    log.info(line)
                self.buffer = lines[-1]

        def flush(self):
            pass

    decorating_loader = DecoratingLoader({
        "ctx": ctx,
        "mounts": mounts,
        "ceph_cluster": ceph_cluster,
        "mds_cluster": mds_cluster,
        "mgr_cluster": mgr_cluster,
    })

    # For the benefit of polling tests like test_full -- in teuthology land we set this
    # in a .yaml, here it's just a hardcoded thing for the developer's pleasure.
    remote.run(args=[os.path.join(BIN_PREFIX, "ceph"), "tell", "osd.*", "injectargs", "--osd-mon-report-interval-max", "5"])
    ceph_cluster.set_ceph_conf("osd", "osd_mon_report_interval_max", "5")

    # Vstart defaults to two segments, which very easily gets a "behind on trimming" health warning
    # from normal IO latency.  Increase it for running teests.
    ceph_cluster.set_ceph_conf("mds", "mds log max segments", "10")

    # Make sure the filesystem created in tests has uid/gid that will let us talk to
    # it after mounting it (without having to  go root).  Set in 'global' not just 'mds'
    # so that cephfs-data-scan will pick it up too.
    ceph_cluster.set_ceph_conf("global", "mds root ino uid", "%s" % os.getuid())
    ceph_cluster.set_ceph_conf("global", "mds root ino gid", "%s" % os.getgid())

    # Monkeypatch get_package_version to avoid having to work out what kind of distro we're on
    def _get_package_version(remote, pkg_name):
        # Used in cephfs tests to find fuse version.  Your development workstation *does* have >=2.9, right?
        return "2.9"

    import teuthology.packaging
    teuthology.packaging.get_package_version = _get_package_version

    overall_suite = load_tests(modules, decorating_loader)

    # Filter out tests that don't lend themselves to interactive running,
    victims = []
    for case, method in enumerate_methods(overall_suite):
        fn = getattr(method, method._testMethodName)

        drop_test = False

        if hasattr(fn, 'is_for_teuthology') and getattr(fn, 'is_for_teuthology') is True:
            drop_test = True
            log.warn("Dropping test because long running: ".format(method.id()))

        if getattr(fn, "needs_trimming", False) is True:
            drop_test = (os.getuid() != 0)
            log.warn("Dropping test because client trim unavailable: ".format(method.id()))

        if drop_test:
            # Don't drop the test if it was explicitly requested in arguments
            is_named = False
            for named in modules:
                if named.endswith(method.id()):
                    is_named = True
                    break

            if not is_named:
                victims.append((case, method))

    log.info("Disabling {0} tests because of is_for_teuthology or needs_trimming".format(len(victims)))
    for s, method in victims:
        s._tests.remove(method)

    if interactive_on_error:
        result_class = InteractiveFailureResult
    else:
        result_class = unittest.TextTestResult
    fail_on_skip = False

    class LoggingResult(result_class):
        def startTest(self, test):
            log.info("Starting test: {0}".format(self.getDescription(test)))
            test.started_at = datetime.datetime.utcnow()
            return super(LoggingResult, self).startTest(test)

        def stopTest(self, test):
            log.info("Stopped test: {0} in {1}s".format(
                self.getDescription(test),
                (datetime.datetime.utcnow() - test.started_at).total_seconds()
            ))

        def addSkip(self, test, reason):
            if fail_on_skip:
                # Don't just call addFailure because that requires a traceback
                self.failures.append((test, reason))
            else:
                super(LoggingResult, self).addSkip(test, reason)

    # Execute!
    result = unittest.TextTestRunner(
        stream=LogStream(),
        resultclass=LoggingResult,
        verbosity=2,
        failfast=True).run(overall_suite)

    if not result.wasSuccessful():
        result.printErrors()  # duplicate output at end for convenience

        bad_tests = []
        for test, error in result.errors:
            bad_tests.append(str(test))
        for test, failure in result.failures:
            bad_tests.append(str(test))

        sys.exit(-1)
    else:
        sys.exit(0)


if __name__ == "__main__":
    exec_test()