Page MenuHomec4science
Files F63090599

bibtaskex.in
No OneTemporary
Actions

File Metadata

Created
Fri, May 17, 17:27

bibtaskex.in
View Options

## $Id$
## BibTaskEx: an example on how to write BibSched tasks.
## This file is part of the CERN Document Server Software (CDSware).
## Copyright (C) 2002 CERN.
##
## The CDSware is free software; you can redistribute it and/or
## modify it under the terms of the GNU General Public License as
## published by the Free Software Foundation; either version 2 of the
## License, or (at your option) any later version.
##
## The CDSware is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
## General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with CDSware; if not, write to the Free Software Foundation, Inc.,
## 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
## read config variables:
#include "config.wml"
#include "configbis.wml"
## start Python:
<protect>#!</protect><PYTHON>
<protect>## $Id$
<protect>## DO NOT EDIT THIS FILE! IT WAS AUTOMATICALLY GENERATED FROM CDSware WML SOURCES.</protect>
## import interesting modules:
pylibdir = "<LIBDIR>/python"
## okay, rest of the Python code goes below
#######
__version__ = "$Id$"
try:
import sys
sys.path.append('%s' % pylibdir)
from cdsware.dbquery import run_sql
import getopt
import marshal
import signal
import sre
import string
import sys
import time
import traceback
except ImportError, e:
print "Error: %s" % e
import sys
sys.exit(1)
cfg_n_default = 30 # how many Fibonacci numbers to calculate if none submitted?
def get_datetime(var, format_string="%Y-%m-%d %H:%M:%S"):
"""Returns a date string according to the format string.
It can handle normal date strings and shifts with respect
to now."""
date = time.time()
shift_re=sre.compile("([-\+]{0,1})([\d]+)([dhms])")
factors = {"d":24*3600, "h":3600, "m":60, "s":1}
m = shift_re.match(var)
if m:
sign = m.groups()[0] == "-" and -1 or 1
factor = factors[m.groups()[2]]
value = float(m.groups()[1])
date = time.localtime(date + sign * factor * value)
date = time.strftime(format_string, date)
else:
date = time.strptime(var, format_string)
date = time.strftime(format_string, date)
return date
def write_message(msg, stream=sys.stdout):
"""Write message and flush output stream (may be sys.stdout or sys.stderr). Useful for debugging stuff."""
if stream == sys.stdout or stream == sys.stderr:
stream.write(time.strftime("%Y-%m-%d %H:%M:%S --> ", time.localtime()))
stream.write("%s\n" % msg)
stream.flush()
else:
sys.stderr.write("Unknown stream %s. [must be sys.stdout or sys.stderr]\n" % stream)
return
def task_sig_sleep(sig, frame):
"""Signal handler for the 'sleep' signal sent by BibSched."""
write_message("sleeping...")
task_update_status("SLEEPING")
signal.pause() # wait for wake-up signal
def task_sig_wakeup(sig, frame):
"""Signal handler for the 'wakeup' signal sent by BibSched."""
write_message("continuing...")
task_update_status("CONTINUING")
def task_sig_stop(sig, frame):
"""Signal handler for the 'stop' signal sent by BibSched."""
write_message("stopping...")
task_update_status("STOPPING")
write_message("flushing cache or whatever...")
time.sleep(3)
write_message("closing tables or whatever...")
time.sleep(1)
write_message("stopped")
task_update_status("STOPPED")
sys.exit(0)
def task_sig_suicide(sig, frame):
"""Signal handler for the 'suicide' signal sent by BibSched."""
write_message("suiciding myself now...")
task_update_status("SUICIDING")
write_message("suicided")
task_update_status("SUICIDED")
sys.exit(0)
def task_sig_unknown(sig, frame):
"""Signal handler for the other unknown signals sent by shell or user."""
write_message("unknown signal %d ignored" % sig) # do nothing for other signals
def fib(n):
"""Returns Fibonacci number for 'n'."""
out = 1
if n >= 2:
out = fib(n-2) + fib(n-1)
return out
def getpass(prompt = "Password: "):
"""Prompts for a password without echoing it back to the screen"""
import termios, sys
fd = sys.stdin.fileno()
old = termios.tcgetattr(fd)
new = termios.tcgetattr(fd)
new[3] = new[3] & ~termios.ECHO # lflags
passwd = ""
try:
termios.tcsetattr(fd, termios.TCSADRAIN, new)
passwd = raw_input(prompt)
print
finally:
termios.tcsetattr(fd, termios.TCSADRAIN, old)
return passwd
def authenticate(user):
"""Authenticates a user against the user database.
NOTE: Access might be more complex in the future"""
print "BibTaskEx Task Submission"
print "========================="
if user == "":
print >> sys.stdout, "\rUsername: ",
user = string.strip(string.lower(sys.stdin.readline()))
else:
print >> sys.stdout, "\rUsername:", user
res = run_sql("select password from user where email=%s", (user,), 1)
if res:
row = res[0]
password_db = row[0]
if password_db != '':
# authentication needed
password_entered = getpass()
if password_db == password_entered:
return user
else:
print "Sorry, you seem to be unauthorized user. Exiting."
sys.exit(1)
else:
# no authentication needed
return user
else:
print "Sorry, %s seems to be unauthorized user. Exiting." % user
sys.exit(1)
def task_submit(options):
"""Submits task to the BibSched task queue. This is what people will be invoking via command line."""
## sanity check: remove eventual "task" option:
if options.has_key("task"):
del options["task"]
## authenticate user:
user = authenticate(options.get("user", ""))
## submit task:
if options["verbose"] >= 9:
print ""
write_message("storing task options %s\n" % options)
task_id = run_sql("""INSERT INTO schTASK (id,proc,user,runtime,sleeptime,status,arguments)
VALUES (NULL,'bibtaskex',%s,%s,%s,'WAITING',%s)""",
(user, options["runtime"], options["sleeptime"], marshal.dumps(options)))
## update task number:
options["task"] = task_id
run_sql("""UPDATE schTASK SET arguments=%s WHERE id=%s""", (marshal.dumps(options),task_id))
write_message("Task #%d submitted." % task_id)
return task_id
def task_update_progress(msg):
"""Updates progress information in the BibSched task table."""
global task_id, options
if options["verbose"] >= 9:
write_message("Updating task progress to %s." % msg)
return run_sql("UPDATE schTASK SET progress=%s where id=%s", (msg, task_id))
def task_update_status(val):
"""Updates status information in the BibSched task table."""
global task_id, options
if options["verbose"] >= 9:
write_message("Updating task status to %s." % msg)
return run_sql("UPDATE schTASK SET status=%s where id=%s", (val, task_id))
def task_read_status(task_id):
"""Read status information in the BibSched task table."""
res = run_sql("SELECT status FROM schTASK where id=%s", (task_id,), 1)
try:
out = res[0][0]
except:
out = 'UNKNOWN'
return out
def task_get_options(id):
"""Returns options for the task 'id' read from the BibSched task queue table."""
out = {}
res = run_sql("SELECT arguments FROM schTASK WHERE id=%s AND proc='bibtaskex'", (id,))
try:
out = marshal.loads(res[0][0])
except:
write_message("Error: BibTaskEx task %d does not seem to exist." % id, sys.stderr)
sys.exit(1)
return out
def task_run():
"""Runs the task by fetching arguments from the BibSched task queue. This is what BibSched will be invoking via daemon call.
The task prints Fibinacci numbers for up to NUM on the stdout, and some messages on stderr.
Return 1 in case of success and 0 in case of failure."""
global task_id, options
options = task_get_options(task_id) # get options from BibSched task table
## check task id:
if not options.has_key("task"):
write_message("Error: The task #%d does not seem to be a BibTaskEx task." % task_id, sys.stderr)
return 0
## check task status:
task_status = task_read_status(task_id)
if task_status != "WAITING":
write_message("Error: The task #%d is %s. I expected WAITING." % (task_id, task_status), sys.stderr)
return 0
## we can run the task now:
if options["verbose"]:
write_message("Task #%d started." % task_id)
task_update_status("RUNNING")
## initialize signal handler:
signal.signal(signal.SIGUSR1, task_sig_sleep)
signal.signal(signal.SIGTERM, task_sig_stop)
signal.signal(signal.SIGABRT, task_sig_suicide)
signal.signal(signal.SIGCONT, task_sig_wakeup)
signal.signal(signal.SIGINT, task_sig_unknown)
## run the task:
if options.has_key("number"):
n = options["number"]
else:
n = cfg_n_default
if options["verbose"] >= 9:
write_message("Printing %d Fibonacci numbers." % n)
for i in range(0,n):
if i > 0 and i % 4 == 0:
if options["verbose"] >= 3:
write_message("Error: water in the CPU. Ignoring and continuing.", sys.stderr)
elif i > 0 and i % 5 == 0:
if options["verbose"]:
write_message("Error: floppy drive dropped on the floor. Ignoring and continuing.", sys.stderr)
if options["verbose"]:
write_message("fib(%d)=%d" % (i, fib(i)))
task_update_progress("Done %d out of %d." % (i,n))
time.sleep(1)
## we are done:
task_update_progress("Done %d out of %d." % (n,n))
task_update_status("DONE")
if options["verbose"]:
write_message("Task #%d finished." % task_id)
return 1
def usage(exitcode=1, msg=""):
"""Prints usage info."""
if msg:
sys.stderr.write("Error: %s.\n" % msg)
sys.stderr.write("Usage: %s [options]\n" % sys.argv[0])
sys.stderr.write("Command options:\n")
sys.stderr.write(" -n, --number=NUM\t Print Fibonacci numbers for up to NUM. [default=%d]\n" % cfg_n_default)
sys.stderr.write("Scheduling options:\n")
sys.stderr.write(" -u, --user=USER \t User name to submit the task as, password needed.\n")
sys.stderr.write(" -t, --runtime=TIME \t Time to execute the task (now), e.g.: +15s, 5m, 3h, 2002-10-27 13:57:26\n")
sys.stderr.write(" -s, --sleeptime=SLEEP \t Sleeping frequency after which to repeat task (no), e.g.: 30m, 2h, 1d\n")
sys.stderr.write("General options:\n")
sys.stderr.write(" -h, --help \t\t Print this help.\n")
sys.stderr.write(" -V, --version \t\t Print version information.\n")
sys.stderr.write(" -v, --verbose=LEVEL \t Verbose level (0=min, 1=default, 9=max).\n")
sys.exit(exitcode)
def main():
"""Main function that analyzes command line input and calls whatever is appropriate.
Useful for learning on how to write BibSched tasks."""
global task_id, options
## parse command line:
if len(sys.argv) == 2 and sys.argv[1].isdigit():
## A - run the task
task_id = int(sys.argv[1])
try:
if not task_run():
write_message("Error occurred. Exiting.", sys.stderr)
except StandardError, e:
write_message("Unexpected error occurred: %s." % e, sys.stderr)
write_message("Traceback is:", sys.stderr)
traceback.print_tb(sys.exc_info()[2])
write_message("Exiting.", sys.stderr)
task_update_status("ERROR")
else:
## B - submit the task
# set default values:
options = {}
options["runtime"] = time.strftime("%Y-%m-%d %H:%M:%S")
options["sleeptime"] = "0"
options["verbose"] = 1
# set user-defined options:
try:
opts, args = getopt.getopt(sys.argv[1:], "hVv:n:u:s:t:", ["help", "version", "verbose=","number=","user=","sleep=","time="])
except getopt.GetoptError, err:
usage(1, err)
try:
for opt in opts:
if opt[0] in ["-h", "--help"]:
usage(0)
elif opt[0] in ["-V", "--version"]:
print __version__
sys.exit(0)
elif opt[0] in [ "-u", "--user"]:
options["user"] = opt[1]
elif opt[0] in ["-v", "--verbose"]:
options["verbose"] = int(opt[1])
elif opt[0] in ["-n", "--number"]:
options["number"]=int(opt[1])
elif opt[0] in [ "-s", "--sleeptime" ]:
get_datetime(opt[1]) # see if it is a valid shift
options["sleeptime"] = opt[1]
elif opt[0] in [ "-t", "--runtime" ]:
options["runtime"] = get_datetime(opt[1])
else:
usage(1)
except StandardError, e:
usage(e)
task_submit(options)
return
### okay, here we go:
if __name__ == '__main__':
main()

Event Timeline

c4science · Help