job.py

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"""! @package job
Primary class for running and managing HPSMC jobs defined by a set of components.
"""
 
import os
import sys
import json
import time
import shutil
import filecmp
import argparse
import getpass
import logging
import glob
import subprocess
import copy
import pathlib
 
from collections.abc import Sequence
from os.path import expanduser
 
from hpsmc._config import convert_config_value
from hpsmc import global_config
 
 
logger = logging.getLogger('hpsmc.job')
 
 
class JobConfig(object):
    """! Wrapper for accessing config information from parser."""
 
    def __init__(self):
        self.parser = copy.copy(global_config)
 
    def __str__(self):
        parser_lines = ['Job configuration:']
        for section in self.parser.sections():
            parser_lines.append("[" + section + "]")
            for i, v in self.parser.items(section):
                parser_lines.append("%s=%s" % (i, v))
            parser_lines.append('')
        return '\n'.join(parser_lines)
 
    def config(self, obj, section=None, required_names=[], allowed_names=[], require_section=True):
        """! Push config into an object by setting an attribute.
        @param obj  object config is pushed to
        @param section  object name (basically name of the component the config is pushed to?)
        @param required_names  list of names of required configurations
        @param allowed_names  list of allowed config names
        """
        if not section:
            section = obj.__class__.__name__
        if self.parser.has_section(section):
            # Check that required settings are there.
            for req in required_names:
                if req not in dict(self.parser.items(section)):
                    raise Exception("Missing required config '%s'" % req)
            # Push each config item into the object by setting attribute.
            for name, value in self.parser.items(section):
                if len(allowed_names) and name not in allowed_names:
                    raise Exception("Config name '%s' is not allowed for '%s'" % (name, section))
                setattr(obj, name, convert_config_value(value))
                # logger.info("%s:%s:%s=%s" % (obj.__class__.__name__,
                #                             name,
                #                             getattr(obj, name).__class__.__name__,
                #                             getattr(obj, name)))
        elif require_section:
            raise Exception("Missing required config section '%s'" % section)
        else:
            logger.warning('Config section not found: %s' % section)
 
 
class JobStore:
    """!
    Simple JSON based store of job data.
    """
 
    def __init__(self, path=None):
        self.path = path
        self.data = {}
        if self.path:
            self.load(self.path)
        else:
            logger.warning('Path was not provided to job store - no jobs loaded!')
 
    def load(self, json_store):
        """! Load raw JSON data into this job store.
        @param json_store  json file containing raw job data
        """
        if not os.path.exists(json_store):
            raise Exception('JSON job store does not exist: {}'.format(json_store))
        with open(json_store, 'r') as f:
            json_data = json.loads(f.read())
        for job_data in json_data:
            if 'job_id' not in job_data:
                raise Exception(f"Job data is missing a job id")
            job_id = int(job_data['job_id'])
            if job_id in self.data:
                raise Exception(f"Duplicate job id: {job_id}")
            self.data[job_id] = job_data
            logger.debug("Loaded job {} data:\n {}".format(job_id, job_data))
        logger.info(f"Successfully loaded {len(self.data)} jobs from: {json_store}")
 
    def get_job(self, job_id):
        """! Get a job by its job ID.
        @param job_id  job ID
        @return job"""
        if not self.has_job_id(job_id):
            raise Exception(f"Job ID does not exist: {job_id}")
        return self.data[int(job_id)]
 
    def get_job_data(self):
        """! Get the raw dict containing all the job data."""
        return self.data
 
    def get_job_ids(self):
        """! Get a sorted list of job IDs."""
        return sorted(self.data.keys())
 
    def has_job_id(self, job_id):
        """! Return true if the job ID exists in the store."""
        return int(job_id) in list(self.data.keys())
 
 
class JobScriptDatabase:
    """! Database of job scripts.
    """
 
    def __init__(self):
        if 'HPSMC_DIR' not in os.environ:
            raise Exception('HPSMC_DIR is not set in the environ.')
        hps_mc_dir = os.environ['HPSMC_DIR']
        script_dir = os.path.join(hps_mc_dir, 'lib', 'python', 'jobs')
        
        self.scripts = {}
        for f in glob.glob(os.path.join(script_dir, '*_job.py')):
            script_name = os.path.splitext(os.path.basename(f))[0].replace('_job', '')
            self.scripts[script_name] = f
 
    def get_script_path(self, name):
        """! Get path to job script from job name.
        @param job name
        @return path to job script"""
        return self.scripts[name]
 
    def get_script_names(self):
        """! Get list of all script names."""
        return list(self.scripts.keys())
 
    def get_scripts(self):
        """! Get dict containing paths to scripts sorted by script names."""
        return self.scripts
 
    def exists(self, name):
        """! Test if job script exists in dict.
        @return True if job name is key in job dict"""
        return name in self.scripts
 
 
class Job(object):
    """!
    Primary class to run HPS jobs from a Python script.
 
    Jobs are run by executing a series of components
    which are configured using a config file with parameters
    provided by a JSON job file.
    """
 
    
    """
    _config_names = ['enable_copy_output_files',
                     'enable_copy_input_files',
                     'enable_cleanup',
                     'delete_existing',
                     'delete_rundir',
                     'dry_run',
                     'ignore_return_codes',
                     'check_output_files',
                     'enable_file_chaining',
                     'enable_env_config']
    """
 
    # Prefix to indicate ptag in job param file.
    PTAG_PREFIX = 'ptag:'
 
    def __init__(self, args=sys.argv, **kwargs):
 
        if 'HPSMC_DIR' not in os.environ:
            raise Exception('HPSMC_DIR is not set in the environ.')
        self.hpsmc_dir = os.environ['HPSMC_DIR']
 
        
        self.args = args
        
        self.job_config = JobConfig()
        
        self.description = "HPS MC Job"
        
        self.job_id = None
        
        self.param_file = None
        
        self.components = []
        
        self.rundir = os.getcwd()
        
        self.params = {}
        
        self.output_dir = os.getcwd()
        
        self.input_files = {}
        
        self.output_files = {}
        
        self.ptags = {}
        
        self.component_out = sys.stdout
        
        self.component_err = sys.stderr
        
        self.script = None
        
        self.job_steps = None
        
        self.hps_fieldmaps_dir = None
 
        
        self.enable_copy_output_files = True
        self.enable_copy_input_files = True
        self.enable_cleanup = True
        self.delete_existing = False
        self.delete_rundir = False
        self.dry_run = False
        self.ignore_return_codes = True
        self.check_output_files = True
        self.check_commands = False
        self.enable_file_chaining = True
        self.enable_env_config = False
 
    def add(self, component):
        """!
        Public method for adding components to the job.
        """
        if isinstance(component, Sequence) and not isinstance(component, str):
            self.components.extend(component)
        else:
            self.components.append(component)
 
    def set_parameters(self, params):
        """!
        Add parameters to the job, overriding values if they exist already.
 
        This method can be used in job scripts to define default values.
        """
        for k, v in params.items():
            if k in self.params:
                logger.debug("Setting new value '%s' for parameter '%s' with existing value '%s'."
                             % (str(v), str(k), params[k]))
            self.params[k] = v
 
    def parse_args(self):
        """!
        Configure the job from command line arguments.
        """
 
        parser = argparse.ArgumentParser(description=self.description)
        parser.add_argument("-c", "--config-file", help="Config file locations", action='append')
        parser.add_argument("-d", "--run-dir", nargs='?', help="Job run dir")
        parser.add_argument("-o", "--out", nargs='?', help="File for component stdout (default prints to console)")
        parser.add_argument("-e", "--err", nargs='?', help="File for component stderr (default prints to console)")
        parser.add_argument("-s", "--job-steps", type=int, default=None, help="Job steps to run (single number)")
        parser.add_argument("-i", "--job-id", type=int, help="Job ID from JSON job store", default=None)
        parser.add_argument("script", nargs='?', help="Path or name of job script")
        parser.add_argument("params", nargs='?', help="Job param file in JSON format")
 
        
 
        cl = parser.parse_args(self.args)
 
        # Read in job configuration files
        if cl.config_file:
            config_files = list(map(os.path.abspath, cl.config_file))
            logger.info("Reading additional config from: {}".format(config_files))
            self.job_config.parser.read(config_files)
 
        # Set file for stdout from components
        if cl.out:
            out_file = cl.out
            if not os.path.isabs(out_file):
                out_file = os.path.abspath(out_file)
                logger.info('Job output will be written to: %s' % out_file)
            self.out = open(out_file, 'w')
 
        # Set file for stderr from components
        if cl.err:
            err_file = cl.err
            if not os.path.isabs(err_file):
                err_file = os.path.abspath(err_file)
                logger.info('Job error will be written to: %s' % err_file)
            self.err = open(err_file, 'w')
 
        if cl.run_dir:
            self.rundir = os.path.abspath(cl.run_dir)
 
        self.job_steps = cl.job_steps
        if self.job_steps is not None and self.job_steps < 1:
            raise Exception("Invalid job steps argument (must be > 0): {}".format(self.job_steps))
 
        if cl.script:
            
            self.script = cl.script
        else:
            raise Exception('Missing required script name or location.')
 
        # Params are actually optional as some job scripts might not need them.
        if cl.params:
            self.param_file = os.path.abspath(cl.params)
            params = {}
            if cl.job_id:
                # Load data from a job store containing multiple jobs.
                self.job_id = cl.job_id
                logger.debug("Loading job with ID %d from job store '%s'" % (self.job_id, self.param_file))
                jobstore = JobStore(self.param_file)
                if jobstore.has_job_id(self.job_id):
                    params = jobstore.get_job(self.job_id)
                else:
                    raise Exception("No job id %d was found in the job store '%s'" % (self.job_id, self.param_file))
            else:
                # Load data from a JSON file with a single job definition.
                logger.info('Loading job parameters from file: %s' % self.param_file)
                params = json.loads(open(self.param_file, 'r').read())
                if not isinstance(params, dict):
                    raise Exception('Job ID must be provided when running from a job store.')
 
            self._load_params(params)
 
    def _load_params(self, params):
        """!
        Load the job parameters from JSON data.
        """
 
        self.set_parameters(params)
 
        # logger.info(json.dumps(self.params, indent=4, sort_keys=False))
 
        if 'output_dir' in self.params:
            self.output_dir = self.params['output_dir']
        if not os.path.isabs(self.output_dir):
            self.output_dir = os.path.abspath(self.output_dir)
            logger.debug("Changed output dir to abs path: %s" % self.output_dir)
 
        if 'job_id' in self.params:
            self.job_id = self.params['job_id']
 
        if 'input_files' in self.params:
            self.input_files = self.params['input_files']
 
        if 'output_files' in self.params:
            self.output_files = self.params['output_files']
 
    def _set_input_files(self):
        """!
        Prepare dictionary of input files.
 
        If a link to a download location is given as input, the file is downloaded into the run directory before the file name is added to the input_files dict. If a regular file is provided, it is added to the dict without any additional action.
        """
        input_files_dict = {}
        for file_key, file_name in self.input_files.items():
            if 'https' in file_key:
                logger.info("Downloading input file from: %s" % file_key)
                file_name_path = self.rundir + "/" + file_name
                # \todo FIXME: We need to make sure wget is installed locally during the build or use a python lib like requests.
                subprocess.check_output(['wget', '-q', '-O', file_name_path, file_key])
                input_files_dict.update({file_name: file_name})
            else:
                input_files_dict.update({file_key: file_name})
        self.input_files = input_files_dict
 
    def _initialize(self):
        """!
        Perform basic initialization before the job script is loaded.
        """
 
        if not os.path.isabs(self.rundir):
            self.rundir = os.path.abspath(self.rundir)
            logger.info('Changed run dir to abs path: %s' % self.rundir)
            # raise Exception('The run dir is not an absolute path: %s' % self.rundir)
 
        # Set run dir if running inside LSF
        if "LSB_JOBID" in os.environ:
            self.rundir = os.path.join("/scratch", getpass.getuser(), os.environ["LSB_JOBID"])
            logger.info('Set run dir for LSF: %s' % self.rundir)
            self.delete_rundir = True
 
        # Create run dir if it does not exist
        if not os.path.exists(self.rundir):
            logger.info('Creating run dir: %s' % self.rundir)
            os.makedirs(self.rundir)
 
    def _configure(self):
        """!
        Configure job class and components.
        """
 
        # Configure job class
        self.job_config.config(self, require_section=False)
 
        # Configure the location of the fieldmap files
        self._config_fieldmap_dir()
 
        # Configure each of the job components
        for component in self.components:
 
            # Configure logging for the component.
            component.config_logging(self.job_config.parser)
 
            # Configure the component from job configuration.
            component.config(self.job_config.parser)
 
            
            if self.enable_env_config:
                # Configure from env vars, if enabled.
                component.config_from_environ()
 
            # Check that the config is acceptable.
            component.check_config()
 
    def _load_script(self):
        """!
        Load the job script.
        """
        # This might be okay if the user is manually adding components to a job for testing
        # without the command line interface. If no components are added before the job is
        # run, then this will be caught later.
        if self.script is None:
            logger.warning("No job script was provided!")
            return
 
        if not self.script.endswith('.py'):
            # Script is a name.
            script_db = JobScriptDatabase()
            if not script_db.exists(self.script):
                raise Exception("The script name is not valid: %s" % self.script)
            script_path = script_db.get_script_path(self.script)
            logger.debug("Found script '%s' from name '%s'" % (script_path, self.script))
        else:
            # Script is a path.
            script_path = self.script
 
        if not os.path.exists(script_path):
            raise Exception('Job script does not exist: %s' % script_path)
 
        logger.info('Loading job script: %s' % script_path)
 
        exec(compile(open(script_path, "rb").read(), script_path, 'exec'), {'job': self})
 
    def run(self):
        """!
        This is the primary execution method for running the job.
        """
 
        logger.info('Job ID: ' + str(self.job_id))
        logger.info('Description: %s' % self.description)
 
        # Print config to the log
        logger.info(str(self.job_config))
 
        # Initialize after CL parameters were parsed.
        self._initialize()
 
        # Load the job components from the script
        self._load_script()
 
        if not len(self.components):
            raise Exception("Job has no components to execute.")
 
        # Print list of job components
        logger.info("Job components loaded: %s" % ([c.name for c in self.components]))
 
        # Print job parameters.
        if len(self.params) > 0:
            logger.info("Job parameters loaded: %s" % str(self.params))
        else:
            logger.info("No job parameters were specified!")
 
        # This will configure the Job class and its components by copying
        # information into them from loaded config files.
        self._configure()
 
        # This (re)sets the input correctly
        self._set_input_files()
 
        # Set component parameters from job JSON file.
        self._set_parameters()
 
        # Perform component setup to prepare for execution.
        # May use config and parameters that were set from above.
        self._setup()
 
        if not self.dry_run:
            if self.enable_copy_input_files:
                # Copy input files to the run dir.
                self._copy_input_files()
            else:
                # Symlink input files if copying is disabled.
                self._symlink_input_files()
 
        # Save job start time
        start_time = time.time()
 
        # Execute the job.
        self._execute()
 
        # Copy the output files to the output dir if enabled and not in dry run.
        if not self.dry_run:
 
            # Print job timer info
            stop_time = time.time()
            elapsed = stop_time - start_time
            logger.info("Job execution took {} seconds".format(round(elapsed, 4)))
 
            # Copy by file path or ptag
            if self.enable_copy_output_files:
                
                self._copy_output_files()
            else:
                logger.warning('Copy output files is disabled!')
 
            # Perform job cleanup.
            if self.enable_cleanup:
                self._cleanup()
 
        logger.info('Successfully finished running job: %s' % self.description)
 
    def _execute(self):
        """!
        Execute all components in job.
 
        If dry_run is set to True, the components will not be exectuted,
        list of components will be put out instead.
        """
        if not self.dry_run:
 
            for component in self.components:
 
                logger.info("Executing '%s' with command: %s" % (component.name, component.cmd_line_str()))
                # logger.info("Component IO: {} -> {}".format(str(component.input_files(), component.output_files())))
 
                # Print header to stdout
                self.component_out.write('================ Component: %s ================\n' % component.name)
                self.component_out.flush()
 
                # Print header to stderr if output is going to a file
                if self.component_err != sys.stderr:
                    self.component_err.write('================ Component: %s ================\n' % component.name)
                    self.component_err.flush()
 
                start = time.time()
                returncode = component.execute(self.component_out, self.component_err)
                end = time.time()
                elapsed = end - start
                logger.info("Execution of {} took {} second(s) with return code: {}"
                            .format(component.name, round(elapsed, 4), str(returncode)))
 
                if not self.ignore_return_codes and returncode:
                    raise Exception("Non-zero return code %d from '%s'" % (returncode, component.name))
 
                if self.check_output_files:
                    for outputfile in component.output_files():
                        if not os.path.isfile(outputfile):
                            raise Exception("Output file '%s' is missing after execution." % outputfile)
        else:
            # Dry run mode. Just print component command but do not execute it.
            logger.info("Dry run enabled. Components will NOT be executed!")
            for component in self.components:
                logger.info("'%s' with args: %s (DRY RUN)" % (component.name, ' '.join(component.cmd_args())))
 
    def _setup(self):
        """!
        Necessary setup before job can be executed.
        """
 
        # Change to run dir
        logger.info('Changing to run dir: %s' % self.rundir)
        os.chdir(self.rundir)
 
        # Create a symlink to the fieldmap directory
        self._symlink_fieldmap_dir()
 
        # Limit components according to job steps
        if self.job_steps is not None:
            if self.job_steps > 0:
                self.components = self.components[0:self.job_steps]
                logger.info("Job is limited to first %d steps." % self.job_steps)
 
        if self.enable_file_chaining:
            self._config_file_pipeline()
 
        # Run setup methods of each component
        for component in self.components:
            logger.debug('Setting up component: %s' % (component.name))
            component.rundir = self.rundir
            component.setup()
            if self.check_commands and not component.cmd_exists():
                raise Exception("Command '%s' does not exist for '%s'." % (component.command, component.name))
 
    def _config_file_pipeline(self):
        """!
        Pipe component outputs to inputs automatically.
        """
        for i in range(0, len(self.components)):
            component = self.components[i]
            logger.debug("Configuring file IO for component '%s' with order %d" % (component. name, i))
            if i == 0:
                logger.debug("Setting inputs on '%s' to: %s"
                             % (component.name, str(list(self.input_files.values()))))
                if not len(component.inputs):
                    component.inputs = list(self.input_files.values())
            elif i > -1:
                logger.debug("Setting inputs on '%s' to: %s"
                             % (component.name, str(self.components[i - 1].output_files())))
                if len(component.inputs) == 0:
                    component.inputs = self.components[i - 1].output_files()
 
    def _set_parameters(self):
        """!
        Push JSON job parameters to components.
        """
        for component in self.components:
            component.set_parameters(self.params)
 
    def _cleanup(self):
        """!
        Perform post-job cleanup.
        """
        for component in self.components:
            logger.info('Running cleanup for component: %s' % str(component.name))
            component.cleanup()
        if self.delete_rundir:
            logger.info('Deleting run dir: %s' % self.rundir)
            if os.path.exists("%s/__swif_env__" % self.rundir):
                for f in os.listdir(self.rundir):
                    if ('.log' not in f) and ('__swif_' not in f):
                        os.system('rm -r %s' % f)
            else:
                shutil.rmtree(self.rundir)
        if self.component_out != sys.stdout:
            try:
                self.component_out.flush()
                self.component_out.close()
            except Exception as e:
                logger.warn(e)
 
        if self.component_err != sys.stderr:
            try:
                self.component_err.flush()
                self.component_err.close()
            except Exception as e:
                logger.warn(e)
 
    def _copy_output_files(self):
        """!
        Copy output files to output directory, handling ptags if necessary.
        """
 
        if not os.path.exists(self.output_dir):
            logger.debug('Creating output dir: %s' % self.output_dir)
            os.makedirs(self.output_dir, 0o755)
 
        for src, dest in self.output_files.items():
            src_file = src
            if Job.is_ptag(src):
                ptag_src = Job.get_ptag_from_src(src)
                if ptag_src in list(self.ptags.keys()):
                    src_file = self.ptags[ptag_src]
                    logger.info("Resolved ptag: {} -> {}".format(ptag_src, src_file))
                else:
                    raise Exception('Undefined ptag used in job params: %s' % ptag_src)
            self._copy_output_file(src_file, dest)
 
    def _copy_output_file(self, src, dest):
        """!
        Copy an output file from src to dest.
        """
 
        src_file = os.path.join(self.rundir, src)
        dest_file = os.path.join(self.output_dir, dest)
 
        # Create directory if not exists; this allows relative path segments
        # in output file strings.
        if not os.path.exists(os.path.dirname(dest_file)):
            os.makedirs(os.path.dirname(dest_file), 0o755)
 
        # Check if the file is already there and does not need copying (e.g. if running in local dir)
        samefile = False
        if os.path.exists(dest_file):
            if os.path.samefile(src_file, dest_file):
                samefile = True
 
        # If target file already exists then see if it can be deleted; otherwise raise an error
        if os.path.isfile(dest_file):
            if self.delete_existing:
                logger.debug('Deleting existing file: %s' % dest_file)
                os.remove(dest_file)
            else:
                raise Exception('Output file already exists: %s' % dest_file)
 
        # Copy the file to the destination dir if not already created by the job
        logger.info("Copying '%s' to '%s'" % (src_file, dest_file))
        if not samefile:
            # shutil will throw and error if the copy obviously fails
            shutil.copyfile(src_file, dest_file)
            # take the time to double-check that the copy is identical to the original
            #   this catches any sneaky network-dropping related copy failures
            if not filecmp.cmp(src_file, dest_file, shallow=False):
                raise Exception("Copy from '%s' to '%s' failed." % (src_file, dest_file))
        else:
            logger.warning("Skipping copy of '%s' to '%s' because they are the same file!" % (src_file, dest_file))
 
    def _copy_input_files(self):
        """!
        Copy input files to the run dir.
        """
        for src, dest in self.input_files.items():
            # if not os.path.isabs(src):
            
            if os.path.dirname(dest):
                raise Exception("The input file destination '%s' is not valid." % dest)
            logger.info("Copying input file: %s -> %s" % (src, os.path.join(self.rundir, dest)))
            if '/mss/' in src:
                src = src.replace('/mss/', '/cache/')
            if os.path.exists(os.path.join(self.rundir, dest)):
                logger.info("The input file '%s' already exists at destination '%s'" % (dest, self.rundir))
                os.chmod(os.path.join(self.rundir, dest), 0o666)
            else:
                shutil.copyfile(src, os.path.join(self.rundir, dest))
            os.chmod(dest, 0o666)
 
    def _symlink_input_files(self):
        """!
        Symlink input files.
        """
        for src, dest in self.input_files.items():
            if not os.path.isabs(src):
                raise Exception('The input source file is not an absolute path: %s' % src)
            if os.path.dirname(dest):
                raise Exception('The input file destination is not valid: %s' % dest)
            logger.debug("Symlinking input '%s' to '%s'" % (src, os.path.join(self.rundir, dest)))
            os.symlink(src, os.path.join(self.rundir, dest))
 
    def ptag(self, tag, filename):
        """!
        Map a key to an output file name so a user can reference it in their job params.
        """
        if tag not in list(self.ptags.keys()):
            self.ptags[tag] = filename
            logger.info("Added ptag %s -> %s" % (tag, filename))
        else:
            raise Exception('The ptag already exists: %s' % tag)
 
    @staticmethod
    def is_ptag(src):
        return src.startswith(Job.PTAG_PREFIX)
 
    @staticmethod
    def get_ptag_from_src(src):
        if src.startswith(Job.PTAG_PREFIX):
            return src[len(Job.PTAG_PREFIX):]
        else:
            raise Exception('File src is not a ptag: %s' % src)
 
    def resolve_output_src(self, src):
        if Job.is_ptag(src):
            return self.ptags[Job.get_ptag_from_src(src)]
        else:
            return src
 
    def _config_fieldmap_dir(self):
        """!
        Set fieldmap dir to install location if not provided in config
        """
        if self.hps_fieldmaps_dir is None:
            self.hps_fieldmaps_dir = "{}/share/fieldmap".format(self.hpsmc_dir)
            if not os.path.isdir(self.hps_fieldmaps_dir):
                raise Exception("The fieldmaps dir does not exist: {}".format(self.hps_fieldmaps_dir))
            logger.debug("Using fieldmap dir from install: {}".format(self.hps_fieldmaps_dir))
        else:
            logger.debug("Using fieldmap dir from config: {}".format(self.hps_fieldmaps_dir))
 
    def _symlink_fieldmap_dir(self):
        """!
        Symlink to the fieldmap directory
        """
        fieldmap_symlink = pathlib.Path(os.getcwd(), "fieldmap")
        if not fieldmap_symlink.exists():
            logger.debug("Creating symlink to fieldmap directory: {}".format(fieldmap_symlink))
            os.symlink(self.hps_fieldmaps_dir, "fieldmap")
        else:
            if fieldmap_symlink.is_dir() or os.path.islink(fieldmap_symlink):
                logger.debug("Fieldmap symlink or directory already exists: {}".format(fieldmap_symlink))
            else:
                raise Exception("A file called 'fieldmap' exists but it is not a symlink or directory!")
 
 
cmds = {
    'run': 'Run a job script',
    'script': 'Show list of available job scripts (provide script name for detailed info)',
    'component': 'Show list of available components (provide component name for detailed info)'}
 
 
def print_usage():
    print("Usage: job.py [command] [args]")
    print("    command:")
    for name, descr in cmds.items():
        print("        %s: %s" % (name, descr))
 
 
if __name__ == '__main__':
    if len(sys.argv) > 1:
        cmd = sys.argv[1]
        if cmd not in list(cmds.keys()):
            print_usage()
            raise Exception('The job command is not valid: %s' % cmd)
        args = sys.argv[2:]
        if cmd == 'run':
            job = Job(args)
            job.parse_args()
            job.run()
        elif cmd == 'script':
            if len(sys.argv) > 2:
                script = sys.argv[2]
                from hpsmc.help import print_job_script
                print_job_script(script)
            else:
                scriptdb = JobScriptDatabase()
                print("AVAILABLE JOB SCRIPTS: ")
                for name in sorted(scriptdb.get_script_names()):
                    print('    %s: %s' % (name, scriptdb.get_script_path(name)))
        elif cmd == 'component':
            if len(sys.argv) > 2:
                from hpsmc.help import print_component
                component_name = sys.argv[2]
                print_component(component_name)
            else:
                from hpsmc.help import print_components
                print_components()
 
    else:
        print_usage()