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# Copyright (c) Microsoft Corporation
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# MIT License
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import argparse
import sys
import os
from subprocess import Popen, PIPE
import time
import logging
import shlex
import re
import sys
import select
from pyhdfs import HdfsClient
import pkg_resources

from .constants import HOME_DIR, LOG_DIR, NNI_PLATFORM, STDOUT_FULL_PATH, STDERR_FULL_PATH
from .hdfsClientUtility import copyDirectoryToHdfs, copyHdfsDirectoryToLocal
from .log_utils import LogType, nni_log, RemoteLogger, PipeLogReader, StdOutputType

logger = logging.getLogger('trial_keeper')

def main_loop(args):
    '''main loop logic for trial keeper'''
    
    if not os.path.exists(LOG_DIR):
        os.makedirs(LOG_DIR)
    
    stdout_file = open(STDOUT_FULL_PATH, 'a+')
    stderr_file = open(STDERR_FULL_PATH, 'a+')
    trial_keeper_syslogger = RemoteLogger(args.nnimanager_ip, args.nnimanager_port, 'trial_keeper', StdOutputType.Stdout, args.log_collection)
    # redirect trial keeper's stdout and stderr to syslog
    trial_syslogger_stdout = RemoteLogger(args.nnimanager_ip, args.nnimanager_port, 'trial', StdOutputType.Stdout, args.log_collection)
    sys.stdout = sys.stderr = trial_keeper_syslogger
    # backward compatibility
    hdfs_host = None
    hdfs_output_dir = None
    if args.hdfs_host:
        hdfs_host = args.hdfs_host
    elif args.pai_hdfs_host:
        hdfs_host = args.pai_hdfs_host
    if args.hdfs_output_dir:
        hdfs_output_dir = args.hdfs_output_dir
    elif args.pai_hdfs_output_dir:
        hdfs_output_dir = args.pai_hdfs_output_dir

    if hdfs_host is not None and args.nni_hdfs_exp_dir is not None:
        try:
            if args.webhdfs_path:
                hdfs_client = HdfsClient(hosts='{0}:80'.format(hdfs_host), user_name=args.pai_user_name, webhdfs_path=args.webhdfs_path, timeout=5)
            else:
                # backward compatibility
                hdfs_client = HdfsClient(hosts='{0}:{1}'.format(hdfs_host, '50070'), user_name=args.pai_user_name, timeout=5)
        except Exception as e:
            nni_log(LogType.Error, 'Create HDFS client error: ' + str(e))
            raise e
        copyHdfsDirectoryToLocal(args.nni_hdfs_exp_dir, os.getcwd(), hdfs_client)

    # Notice: We don't appoint env, which means subprocess wil inherit current environment and that is expected behavior
    log_pipe_stdout = trial_syslogger_stdout.get_pipelog_reader()
    process = Popen(args.trial_command, shell = True, stdout = log_pipe_stdout, stderr = log_pipe_stdout)
    nni_log(LogType.Info, 'Trial keeper spawns a subprocess (pid {0}) to run command: {1}'.format(process.pid, shlex.split(args.trial_command)))

    while True:
        retCode = process.poll()
        # child worker process exits and all stdout data is read
        if retCode is not None and log_pipe_stdout.set_process_exit() and log_pipe_stdout.is_read_completed == True:
            nni_log(LogType.Info, 'subprocess terminated. Exit code is {}. Quit'.format(retCode))
            if hdfs_output_dir is not None:
                # Copy local directory to hdfs for OpenPAI
                nni_local_output_dir = os.environ['NNI_OUTPUT_DIR']
                try:
                    if copyDirectoryToHdfs(nni_local_output_dir, hdfs_output_dir, hdfs_client):
                        nni_log(LogType.Info, 'copy directory from {0} to {1} success!'.format(nni_local_output_dir, hdfs_output_dir))
                    else:
                        nni_log(LogType.Info, 'copy directory from {0} to {1} failed!'.format(nni_local_output_dir, hdfs_output_dir))
                except Exception as e:
                    nni_log(LogType.Error, 'HDFS copy directory got exception: ' + str(e))
                    raise e

            ## Exit as the retCode of subprocess(trial)
            exit(retCode)
            break

        time.sleep(2)

def trial_keeper_help_info(*args):
    print('please run --help to see guidance')

def check_version(args):
    try:
        trial_keeper_version = pkg_resources.get_distribution('nni').version
    except pkg_resources.ResolutionError as err:
        #package nni does not exist, try nni-tool package
        nni_log(LogType.Error, 'Package nni does not exist!')
        os._exit(1)
    if not args.version:
        # skip version check
        nni_log(LogType.Warning, 'Skipping version check!')
    else:
        regular = re.compile('v?(?P<version>[0-9](\.[0-9]){0,2}).*')
        try:
            trial_keeper_version = regular.search(trial_keeper_version).group('version')
            nni_log(LogType.Info, 'trial_keeper_version is {0}'.format(trial_keeper_version))
            training_service_version = regular.search(args.version).group('version')
            nni_log(LogType.Info, 'training_service_version is {0}'.format(training_service_version))
            if trial_keeper_version != training_service_version:
                nni_log(LogType.Error, 'Version does not match!')
                os._exit(1)
            else:
                nni_log(LogType.Info, 'Version match!')
        except AttributeError as err:
            nni_log(LogType.Error, err)

if __name__ == '__main__':
    '''NNI Trial Keeper main function'''
    PARSER = argparse.ArgumentParser()
    PARSER.set_defaults(func=trial_keeper_help_info)
    PARSER.add_argument('--trial_command', type=str, help='Command to launch trial process')
    PARSER.add_argument('--nnimanager_ip', type=str, default='localhost', help='NNI manager rest server IP')
    PARSER.add_argument('--nnimanager_port', type=str, default='8081', help='NNI manager rest server port')
    PARSER.add_argument('--pai_hdfs_output_dir', type=str, help='the output dir of pai_hdfs') # backward compatibility
    PARSER.add_argument('--hdfs_output_dir', type=str, help='the output dir of hdfs')
    PARSER.add_argument('--pai_hdfs_host', type=str, help='the host of pai_hdfs') # backward compatibility
    PARSER.add_argument('--hdfs_host', type=str, help='the host of hdfs')
    PARSER.add_argument('--pai_user_name', type=str, help='the username of hdfs')
    PARSER.add_argument('--nni_hdfs_exp_dir', type=str, help='nni experiment directory in hdfs')
    PARSER.add_argument('--webhdfs_path', type=str, help='the webhdfs path used in webhdfs URL')
    PARSER.add_argument('--version', type=str, help='the nni version transmitted from trainingService')
    PARSER.add_argument('--log_collection', type=str, help='set the way to collect log in trialkeeper')
    args, unknown = PARSER.parse_known_args()
    if args.trial_command is None:
        exit(1)
    check_version(args)
    try:
        main_loop(args)
    except SystemExit as se:
        nni_log(LogType.Info, 'NNI trial keeper exit with code {}'.format(se.code))
        os._exit(se.code)
    except Exception as e:
        nni_log(LogType.Error, 'Exit trial keeper with code 1 because Exception: {} is catched'.format(str(e)))
        os._exit(1)

