Native Python Tasks

Here is an example of a script as a local native python task:

There are several ways of doing this. The following are examples.

•  There are two ways of accessing the ecflow child commands(init,event,meter, label,abort,complete). 
   We can either call the child commands directly using ecflow extension, or we can call system command to access ecflow_clent. 
   The following examples will use ecflow python extension. However this requires that PYTHONPATH is set directory where ecflow.so extension was installed.

• definition file:
  The default ECF_MICRO is %, this may interfere with your python scripts. In this case you either redefine it, in the task definition or directly in the python script.

    task python
      edit ECF_MICRO '$'
      edit ECF_JOB_CMD 'python $ECF_JOB$ > $ECF_JOBOUT$ 2>&1'
      label info "none"
      meter step -1 100 100
      event 1
      event 2

• Header

  python header

  import os, time, signal, sys
  import ecflow
   
  print "PYTHONPATH====================================================="
  print os.environ['PYTHONPATH'].split(os.pathsep)
  class Client(object):
     def __init__(self):
        print "Creating Client"
        self.ci = ecflow.Client()
        self.ci.set_host_port("%ECF_NODE%","%ECF_PORT%")
        self.ci.set_child_pid(os.getpid())
        self.ci.set_child_path("%ECF_NAME%")
        self.ci.set_child_password("%ECF_PASS%")
        self.ci.set_child_try_no(%ECF_TRYNO%)
     
        print "Only wait 20 seconds, if the server cannot be contacted (note default is 24 hours) before failing"
        self.ci.set_child_timeout(20) 
      
        signal.signal(signal.SIGINT,  self.signal_handler) 
        signal.signal(signal.SIGHUP,  self.signal_handler)
        signal.signal(signal.SIGQUIT, self.signal_handler)
        signal.signal(signal.SIGILL,  self.signal_handler)
        signal.signal(signal.SIGTRAP, self.signal_handler)
        signal.signal(signal.SIGIOT,  self.signal_handler)
        signal.signal(signal.SIGBUS,  self.signal_handler)
        signal.signal(signal.SIGFPE,  self.signal_handler)
        signal.signal(signal.SIGUSR1, self.signal_handler)
        signal.signal(signal.SIGUSR2, self.signal_handler)
        signal.signal(signal.SIGPIPE, self.signal_handler)
        signal.signal(signal.SIGTERM, self.signal_handler)
        signal.signal(signal.SIGXCPU, self.signal_handler)
        signal.signal(signal.SIGPWR,  self.signal_handler)
      
     def signal_handler(self,signum, frame):
        print 'Aborting: Signal handler called with signal ', signum
        self.ci.child_abort("Signal handler called with signal " + str(signum));
      
     def __enter__(self):
        self.ci.child_init()
        return self.ci
      
     def __exit__(self,ex_type,value,tb):
        print "Client:__exit__: ex_type:" + str(ex_type) + " value:" + str(value) + "\n" + str(tb)
        if ex_type != None:
           self.ci.child_abort("Aborted with exception type " + str(ex_type) + str(value))
           return False
        self.ci.child_complete()
        return False

  This header will automatically handle calling the child command init() and complete(), it will also handle any signals, and exceptions. In which case it call abort automatically

  task wrapper:

  $include <head.py>
  $manual
     This is the manual section. Instead of calling python from the ECF_JOB_CMD we could alternatively place,
         #!/bin/env/python
     on the first line of this file.
  $end
  
  $comment
     Note: We do not need a tail,
  $end
   
  # This will also handle call to sys.exit(), i.e Client.__exit__ will still be called.
  with Client() as ci:
     for i in range(1,100):
        ci.child_meter('step',i)
        ci.child_label('info', "value_" + str(i))
        time.sleep(1)
        
     ci.child_event('event_fred')
     print "Finished event,meter and label child commands"