Crated proper directory

operations/tape/cta-supply-pool-mechanism/supply-pool-refill-mechanism

+#!/usr/bin/python36
+
+# The CERN Tape Archive (CTA) project
+# Copyright (C) 2019  CERN
+#
+# This program 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 3 of the License, or
+# (at your option) any later version.
+#
+# This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Logic:
+# * CTA tape pool should have at least X partial tapes available for writing
+# * Eligible partial tapes are those that are not DISABLED, not FULL and not
+#   in a DISABLED logical tape library
+# * If the number of eligible partial tapes for a given pool falls below the
+#   configured limit, the pool needs to be re-supplied with fresh tapes
+# * Fresh supply tapes are taken from tape pools defined in the "supply" column
+# * Supply tape pools can be separated by a separator (usually comma)
+# * There is no distinction between what is a supply pool and what is not, if
+#   a pool has a value in the "supply" column, tapes are taken from there.
+#   Because of this, irregularities, cyclical loops and other misconfiguration
+#   are possible - please be careful
+# * This script is intended to run every 15 minutes
+#
+# Author: Vladimir Bahyl - 7/2019
+
+import sys
+import json
+import logging
+from random import shuffle
+from datetime import datetime
+from subprocess import STDOUT, check_output
+
+##########
+#
+# CONFIGURATION
+#
+##########
+
+timeout = 10	# how many seconds to wait for the external command to finish
+separator = ","	# characted which separates multiple tape pools in the CTA "supply" column
+ctaadmin = "/usr/bin/cta-admin"
+
+# Configure logging
+logfile = sys.argv[0] + ".log"
+logging.basicConfig (
+    level    = logging.INFO,				# only messages with log level above this are logged (DEBUG, INFO, WARN, ERROR)
+    format   = "[%(levelname)-5.5s] %(message)s",	# format of the logging (can be very complex - see the manual)
+    handlers = [
+        logging.FileHandler(logfile), 			# log to a logfile
+        logging.StreamHandler()				# log to console STDOUT
+    ])
+
+##########
+#
+# FUNCTIONS
+#
+##########
+
+# Extract eligible (not DISABLED, not FULL and NOT in a DISABLED library) tapes from a given tape pool
+def extract_eligible_tapes(disabledlibraries, tapepool):
+    tapes = []
+    command = [ctaadmin, "--json", "tape", "ls", "--tapepool", tapepool, "--disabled", "false", "--full", "false"]
+    try:
+        logging.debug("Executing command " + format(command) + " with timeout of " + format(timeout) + " seconds")
+        output = check_output(command, stderr = STDOUT, timeout = timeout).decode("UTF-8")
+    except Exception as error:
+        logging.error(format(error))
+        sys.exit(-1)
+
+    if output:
+        tapes = [line["vid"] for line in json.loads(output) if not line["logicalLibrary"] in disabledlibraries]
+    else:
+        logging.warn("No eligible tapes identified in the tape pool: " + tapepool)
+
+    return tapes
+
+##########
+#
+# MAIN
+#
+##########
+logging.info("Current time: " + format(datetime.now().strftime('%Y-%m-%d %H:%M:%S')))
+
+# Extract the list of all tape pools from CTA (in the JSON format)
+command = [ctaadmin, "--json", "tapepool", "ls"]
+try:
+    logging.debug("Executing command " + format(command) + " with timeout of " + format(timeout) + " seconds")
+    output = check_output(command, stderr = STDOUT, timeout = timeout).decode("UTF-8")
+except Exception as error:
+    logging.error(format(error))
+    sys.exit(-1)
+if output:
+    tapepools = json.loads(output)
+else:
+    logging.error("List of CTA tape pools is empty, nothing to do, exiting")
+    sys.exit(0)
+#logging.debug("List of extracted tape pools from CTA: " + format(tapepools))
+
+# Extract the list of DISABLED tape libraries from CTA (in the JSON format)
+command = [ctaadmin, "--json", "logicallibrary", "ls"]
+try:
+    logging.debug("Executing command " + format(command) + " with timeout of " + format(timeout) + " seconds")
+    output = check_output(command, stderr = STDOUT, timeout = timeout).decode("UTF-8")
+except Exception as error:
+    logging.error(format(error))
+    sys.exit(-1)
+if output:
+    disabledlibraries = [line["name"] for line in json.loads(output) if line["isDisabled"] ]
+else:
+    logging.info("No DISABLED logical tape libraries detected, considering tapes from all libraries")
+if disabledlibraries: logging.warn("List of DISABLED logical tape libraries: " + format(disabledlibraries))
+
+# Iterate over the extracted CTA tape pools and re-fill them with supply tapes as needed
+for tapepool in tapepools:
+    logging.info("Tape pool: " + tapepool["name"] + " which should have at least: " + tapepool["numPartialTapes"] + " eligible partial tape(s) is supplied from: " + tapepool["supply"])
+
+    if (tapepool["numPartialTapes"] and tapepool["supply"]):
+
+        # Check if re-filling is actually needed
+        currentpartialtapes = len([tape for tape in extract_eligible_tapes(disabledlibraries, tapepool["name"])])
+        if (currentpartialtapes < int(tapepool["numPartialTapes"])):
+            logging.info("Tape pool: " + tapepool["name"] + " only has: " + format(currentpartialtapes) + " eligible partial tape(s) available, re-filling")
+        else:
+            logging.info("Tape pool: " + tapepool["name"] + " already has: " + format(currentpartialtapes) + " eligible partial tape(s) available, skipping")
+            continue
+
+        # Prepare the eligible supply tapes from a given supply pool(s)
+        supplytapes = []
+        for supplypool in tapepool["supply"].split(separator):
+            supplytapes.extend([tape for tape in extract_eligible_tapes(disabledlibraries, supplypool)])
+        shuffle(supplytapes) # Randomize it (so that tapes are picked at random from multiple pools)
+
+        # Move the required number of supply tapes to the given tape pool (if any eligible tapes were identified)
+        if len(supplytapes):
+            logging.info("Identified: " + format(len(supplytapes)) + " supply tapes, moving random " + format(int(tapepool["numPartialTapes"]) - currentpartialtapes) + " to the pool: " + tapepool["name"])
+            for i in range(int(tapepool["numPartialTapes"]) - currentpartialtapes):
+                if i < len(supplytapes):
+                    command = [ctaadmin, "tape", "ch", "--vid", supplytapes[i], "--tapepool", tapepool["name"]]
+                    try:
+                        logging.debug("Executing command " + format(command) + " with timeout of " + format(timeout) + " seconds")
+#                        output = check_output(command, stderr = STDOUT, timeout = timeout).decode("UTF-8")
+                    except Exception as error:
+                        logging.error(format(error))
+                        sys.exit(-1)
+                    logging.info("Tape: " + format(supplytapes[i]) + " moved to the pool: " + tapepool["name"])
+                else:
+                    logging.warn("Unable to completely re-fill the tape pool: " + tapepool["name"] + ", run out of supply tapes")
+        else:
+            logging.warn("Unable to re-fill the tape pool: " + tapepool["name"] + ", no eligible supply tapes identified")
+
+    else:
+        logging.warn("Unable to re-fill the tape pool: " + tapepool["name"] + " because either the number of eligible partial tapes: " + tapepool["numPartialTapes"] + " or the supply pool: " + tapepool["supply"] + " is not properly configured")