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

# Copyright 2014 IBM Corporation
# Copyright 2015-2017 Lenovo
#
# 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.

# This is the main application.
# It should check for existing UDP socket to negotiate socket listen takeover
# It will have three paths into it:
#   -Unix domain socket
#   -TLS socket
#   -WSGI
# Additionally, it will be able to receive particular UDP packets to facilitate
# Things like heartbeating and discovery
# It also will optionally snoop SLP DA requests

import atexit
import confluent.auth as auth
import confluent.config.conf as conf
import confluent.config.configmanager as configmanager
try:
    import anydbm as dbm
except ModuleNotFoundError:
    import dbm
import confluent.consoleserver as consoleserver
import confluent.core as confluentcore
import confluent.httpapi as httpapi
import confluent.log as log
import confluent.collective.manager as collective
import confluent.discovery.protocols.pxe as pxe
try:
    import confluent.sockapi as sockapi
except ImportError:
    #On platforms without pwd, give up on the sockapi in general and be http
    #only for now
    pass
import confluent.discovery.core as disco
import eventlet
dbgif = False
try:
    import eventlet.backdoor as backdoor
    dbgif = True
except Exception:
    pass
havefcntl = True
try:
    import fcntl
except ImportError:
    havefcntl = False
#import multiprocessing
import gc
from greenlet import greenlet
import sys
import os
import glob
import signal
import socket
import subprocess
import time
import traceback
import tempfile
import uuid


def _daemonize():
    if not 'fork' in os.__dict__:
        return
    thispid = os.fork()
    if thispid > 0:
        os.waitpid(thispid, 0)
        os._exit(0)
    os.setsid()
    thispid = os.fork()
    if thispid > 0:
        print('confluent server starting as pid {0}'.format(thispid))
        os._exit(0)
    os.closerange(0, 2)
    os.open(os.devnull, os.O_RDWR)
    os.dup2(0, 1)
    os.dup2(0, 2)
    log.daemonized = True


def _redirectoutput():
    os.umask(63)
    configmanager.set_global('logdirectory', _get_logdirectory())
    sys.stdout = log.Logger('stdout', buffered=False)
    sys.stderr = log.Logger('stderr', buffered=False)


def _updatepidfile():
    pidfile = open('/var/run/confluent/pid', 'w+')
    fcntl.flock(pidfile, fcntl.LOCK_EX)
    pidfile.write(str(os.getpid()))
    fcntl.flock(pidfile, fcntl.LOCK_UN)
    pidfile.close()


def is_running():
    # Utility function for utilities to check if confluent is running
    try:
        pidfile = open('/var/run/confluent/pid', 'r+')
        fcntl.flock(pidfile, fcntl.LOCK_SH)
        pid = pidfile.read()
        if pid != '':
            try:
                os.kill(int(pid), 0)
                return pid
            except OSError:
                # There is no process running by that pid, must be stale
                pass
        fcntl.flock(pidfile, fcntl.LOCK_UN)
        pidfile.close()
    except IOError:
        pass
    return None


def _checkpidfile():
    try:
        pidfile = open('/var/run/confluent/pid', 'r+')
        fcntl.flock(pidfile, fcntl.LOCK_EX)
        pid = pidfile.read()
        if pid != '':
            try:
                os.kill(int(pid), 0)
                print ('/var/run/confluent/pid exists and indicates %s is still '
                       'running' % pid)
                sys.exit(1)
            except OSError:
                # There is no process running by that pid, must be stale
                pass
        pidfile.seek(0)
        pidfile.write(str(os.getpid()))
        fcntl.flock(pidfile, fcntl.LOCK_UN)
        pidfile.close()
    except IOError:
        try:
            pidfile = open('/var/run/confluent/pid', 'w')
        except IOError as e:
            if e.errno != 2:
                raise
            os.makedirs('/var/run/confluent')
            pidfile = open('/var/run/confluent/pid', 'w')
        fcntl.flock(pidfile, fcntl.LOCK_EX)
        pidfile.write(str(os.getpid()))
        fcntl.flock(pidfile, fcntl.LOCK_UN)
        pidfile.close()
        pidfile = open('/var/run/confluent/pid', 'r')
        fcntl.flock(pidfile, fcntl.LOCK_SH)
        pid = pidfile.read()
        if pid != str(os.getpid()):
            print ('/var/run/confluent/pid exists and indicates %s is still '
                   'running' % pid)
            sys.exit(1)
        fcntl.flock(pidfile, fcntl.LOCK_UN)
        pidfile.close()


def terminate(signalname, frame):
    sys.exit(0)

def dumptrace(signalname, frame):
    ht = open('/var/log/confluent/hangtraces', 'a')
    ht.write('Dumping active trace on ' + time.strftime('%X %x\n'))
    ht.write(''.join(traceback.format_stack(frame)))
    for o in gc.get_objects():
        if not isinstance(o, greenlet):
            continue
        if not o:
            continue
        ht.write('Thread trace: ({0})\n'.format(id(o)))
        ht.write(''.join(traceback.format_stack(o.gr_frame)))
    ht.close()

def doexit():
    if not havefcntl:
        return
    try:
        os.remove('/var/run/confluent/dbg.sock')
    except OSError:
        pass
    pidfile = open('/var/run/confluent/pid')
    pid = pidfile.read()
    if pid == str(os.getpid()):
        os.remove('/var/run/confluent/pid')


def _initsecurity(config):
    if config.has_option('security', 'externalcfgkey'):
        keyfile = config.get('security', 'externalcfgkey')
        with open(keyfile, 'r') as keyhandle:
            key = keyhandle.read()
        configmanager.init_masterkey(key)
        # We don't want to os._exit() until sync finishes from
        # init above
        configmanager.ConfigManager.wait_for_sync()


def setlimits():
    try:
        import resource
        currlimit = resource.getrlimit(resource.RLIMIT_NOFILE)
        if currlimit[0] < currlimit[1]:
            resource.setrlimit(
                resource.RLIMIT_NOFILE, (currlimit[1], currlimit[1]))
    except Exception:
        pass

def assure_ownership(path):
    try:
        if os.getuid() != os.stat(path).st_uid:
            if os.getuid() == 0:
                sys.stderr.write('Attempting to run as root, when non-root usage is detected\n')
            else:
                sys.stderr.write('{} is not owned by confluent user, change ownership\n'.format(path))
            sys.exit(1)
    except OSError as e:
        if e.errno == 13:
            if os.getuid() == 0:
                sys.stderr.write('Attempting to run as root, when non-root usage is detected\n')
            else:
                sys.stderr.write('{} is not owned by confluent user, change ownership\n'.format(path))
            sys.exit(1)

def sanity_check():
    assure_ownership('/etc/confluent')
    assure_ownership('/etc/confluent/cfg')
    for filename in glob.glob('/etc/confluent/cfg/*'):
        assure_ownership(filename)
    assure_ownership('/etc/confluent/privkey.pem')
    assure_ownership('/etc/confluent/srvcert.pem')


def migrate_db():
    tdir = tempfile.mkdtemp()
    subprocess.check_call(['python3', '-c', 'pass'])
    subprocess.check_call(['python2', '/opt/confluent/bin/confluentdbutil', 'dump', '-u', tdir])
    subprocess.check_call(['python3', '/opt/confluent/bin/confluentdbutil', 'restore', '-u', tdir])
    subprocess.check_call(['rm', '-rf', tdir])
    configmanager.init()


def run(args):
    setlimits()
    try:
        configmanager.ConfigManager(None)
    except dbm.error:
        migrate_db()
    try:
        signal.signal(signal.SIGUSR1, dumptrace)
    except AttributeError:
        pass   # silly windows
    if havefcntl:
        _checkpidfile()
    conf.init_config()
    try:
        config = conf.get_config()
        _initsecurity(config)
    except:
        sys.stderr.write("Error unlocking credential store\n")
        doexit()
        sys.exit(1)
    sanity_check()
    try:
        confluentcore.load_plugins()
    except:
        doexit()
        raise
    try:
        log.log({'info': 'Confluent management service starting'}, flush=True)
    except (OSError, IOError) as e:
        print(repr(e))
        sys.exit(1)
    if '-f' not in args:
        _daemonize()
    if '-o' not in args:
        _redirectoutput()
    if havefcntl:
        _updatepidfile()
    signal.signal(signal.SIGINT, terminate)
    signal.signal(signal.SIGTERM, terminate)
    atexit.register(doexit)
    confluentuuid = configmanager.get_global('confluent_uuid')
    if not confluentuuid:
        confluentuuid = str(uuid.uuid4())
        configmanager.set_global('confluent_uuid', confluentuuid)
    if not configmanager._masterkey:
        configmanager.init_masterkey()
    if dbgif:
        oumask = os.umask(0o077)
        try:
            os.remove('/var/run/confluent/dbg.sock')
        except OSError:
            pass  # We are not expecting the file to exist
        try:
            dbgsock = eventlet.listen("/var/run/confluent/dbg.sock",
                                       family=socket.AF_UNIX)
            eventlet.spawn_n(backdoor.backdoor_server, dbgsock)
        except AttributeError:
            pass  # Windows...
        os.umask(oumask)
    auth.check_for_yaml()
    collective.startup()
    consoleserver.initialize()
    http_bind_host, http_bind_port = _get_connector_config('http')
    sock_bind_host, sock_bind_port = _get_connector_config('socket')
    try:
        sockservice = sockapi.SockApi(sock_bind_host, sock_bind_port)
        sockservice.start()
    except NameError:
        pass
    webservice = httpapi.HttpApi(http_bind_host, http_bind_port)
    webservice.start()
    while len(list(configmanager.list_collective())) >= 2:
        # If in a collective, stall automatic startup activity
        # until we establish quorum
        try:
            configmanager.check_quorum()
            break
        except Exception:
            eventlet.sleep(0.5)
    eventlet.spawn_n(disco.start_detection)
    eventlet.sleep(1)
    consoleserver.start_console_sessions()
    while 1:
        eventlet.sleep(100)

def _get_connector_config(session):
    host = conf.get_option(session, 'bindhost')
    port = conf.get_int_option(session, 'bindport')
    return (host, port)

def _get_logdirectory():
    return conf.get_option('globals', 'logdirectory')