Adding first draft version of the supply pool refill mechanism

operations/tape/supply-pool-refill-mechanism

+#!/usr/bin/python36
+
+import sys
+import json
+import logging
+from random import shuffle
+from subprocess import STDOUT, check_output, CalledProcessError
+
+##########
+#
+# 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
+
+# Configure logging
+logfile = sys.argv[0] + ".log"
+logging.basicConfig (
+    level    = logging.DEBUG,				# only messages with log level above this are logged
+    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_tapes(tapelibrary, tapepool):
+    tapes = []
+    command = ["/usr/bin/cta-admin", "--json", "tape", "ls", "--tapepool", tapepool, "--disabled", "false", "--full", "false"]
+    if ((tapelibrary) and (tapelibrary != "ALL")):
+        command.extend(["--logicallibrary", tapelibrary])
+    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 == "]": output = "" # TEMPORARY UNTIL --json FIXED !!!
+    if output:
+        tapes = [line["vid"] for line in json.loads(output)]
+    else:
+        logging.warn("No eligible tapes extracted from the tape pool: " + tapepool)
+
+    return tapes
+
+##########
+#
+# MAIN
+#
+##########
+
+# Extract the list of all tape pools in CTA in JSON format
+command = ["/usr/bin/cta-admin", "--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)
+
+# Extract the list of DISABLED tape libraries
+# LATER as --json not yet implemented
+
+#logging.debug("List of extracted tape pools from CTA:\n" + format(tapepools))
+
+# 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"] + " 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_tapes("ALL", tapepool["name"])])
+        if (currentpartialtapes < int(tapepool["numPartialTapes"])):
+            logging.info("Tape pool: " + tapepool["name"] + " only has: " + format(currentpartialtapes) + " partial tape(s) available, re-filling")
+        else:
+            logging.info("Tape pool: " + tapepool["name"] + " already has: " + format(currentpartialtapes) + " partial tape(s) available, skipping")
+            continue
+
+        # Prepare the eligible supply tapes from a given supply pool
+        supplytapes = []
+        for supplypool in tapepool["supply"].split(separator):
+            supplytapes.extend([tape for tape in extract_tapes("ALL", supplypool)])
+        shuffle(supplytapes) # Randomize it (so that tapes are picked at random from multiple pools)
+
+        if len(supplytapes):
+            # Move the required number of supply tapes to the given tape pool
+            logging.info("Identified: " + format(len(supplytapes)) + " supply tapes, moving " + format(int(tapepool["numPartialTapes"]) - currentpartialtapes) + " to the pool: " + tapepool["name"])
+            for i in range(int(tapepool["numPartialTapes"]) - currentpartialtapes):
+                command = ["/usr/bin/cta-admin", "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 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 partial tapes: " + tapepool["numPartialTapes"] + " or the supply pool: " + tapepool["supply"] + " is not properly configured")