Split health monitoring into discrete daemon/pkg

health-daemon/pvchealthd/Daemon.py

@@ -0,0 +1,145 @@
+#!/usr/bin/env python3
+
+# Daemon.py - Health daemon main entrypoing
+# Part of the Parallel Virtual Cluster (PVC) system
+#
+#    Copyright (C) 2018-2022 Joshua M. Boniface <joshua@boniface.me>
+#
+#    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, version 3.
+#
+#    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 <https://www.gnu.org/licenses/>.
+#
+###############################################################################
+
+import pvchealthd.util.config
+import pvchealthd.util.zookeeper
+
+import pvchealthd.objects.MonitoringInstance as MonitoringInstance
+import pvchealthd.objects.NodeInstance as NodeInstance
+
+import daemon_lib.log as log
+
+from time import sleep
+
+import os
+import signal
+
+# Daemon version
+version = "0.9.82"
+
+
+##########################################################
+# Entrypoint
+##########################################################
+
+
+def entrypoint():
+    monitoring_instance = None
+
+    # Get our configuration
+    config = pvchealthd.util.config.get_configuration()
+    config["daemon_name"] = "pvchealthd"
+    config["daemon_version"] = version
+
+    # Set up the logger instance
+    logger = log.Logger(config)
+
+    # Print our startup message
+    logger.out("")
+    logger.out("|------------------------------------------------------------|")
+    logger.out("|                                                            |")
+    logger.out("|            ███████████ ▜█▙      ▟█▛ █████ █ █ █            |")
+    logger.out("|                     ██  ▜█▙    ▟█▛  ██                     |")
+    logger.out("|            ███████████   ▜█▙  ▟█▛   ██                     |")
+    logger.out("|            ██             ▜█▙▟█▛    ███████████            |")
+    logger.out("|                                                            |")
+    logger.out("|------------------------------------------------------------|")
+    logger.out("| Parallel Virtual Cluster health daemon v{0: <18} |".format(version))
+    logger.out("| Debug: {0: <51} |".format(str(config["debug"])))
+    logger.out("| FQDN: {0: <52} |".format(config["node_fqdn"]))
+    logger.out("| Host: {0: <52} |".format(config["node_hostname"]))
+    logger.out("| ID: {0: <54} |".format(config["node_id"]))
+    logger.out("| IPMI hostname: {0: <43} |".format(config["ipmi_hostname"]))
+    logger.out("| Machine details:                                           |")
+    logger.out("|   CPUs: {0: <50} |".format(config["static_data"][0]))
+    logger.out("|   Arch: {0: <50} |".format(config["static_data"][3]))
+    logger.out("|   OS: {0: <52} |".format(config["static_data"][2]))
+    logger.out("|   Kernel: {0: <48} |".format(config["static_data"][1]))
+    logger.out("|------------------------------------------------------------|")
+    logger.out("")
+    logger.out(f'Starting pvchealthd on host {config["node_fqdn"]}', state="s")
+
+    # Connect to Zookeeper and return our handler and current schema version
+    zkhandler, _ = pvchealthd.util.zookeeper.connect(logger, config)
+
+    # Define a cleanup function
+    def cleanup(failure=False):
+        nonlocal logger, zkhandler, monitoring_instance
+
+        logger.out("Terminating pvchealthd and cleaning up", state="s")
+
+        # Shut down the monitoring system
+        try:
+            logger.out("Shutting down monitoring subsystem", state="s")
+            monitoring_instance.shutdown()
+        except Exception:
+            pass
+
+        # Close the Zookeeper connection
+        try:
+            zkhandler.disconnect(persistent=True)
+            del zkhandler
+        except Exception:
+            pass
+
+        logger.out("Terminated health daemon", state="s")
+        logger.terminate()
+
+        if failure:
+            retcode = 1
+        else:
+            retcode = 0
+
+        os._exit(retcode)
+
+    # Termination function
+    def term(signum="", frame=""):
+        cleanup(failure=False)
+
+    # Hangup (logrotate) function
+    def hup(signum="", frame=""):
+        if config["file_logging"]:
+            logger.hup()
+
+    # Handle signals gracefully
+    signal.signal(signal.SIGTERM, term)
+    signal.signal(signal.SIGINT, term)
+    signal.signal(signal.SIGQUIT, term)
+    signal.signal(signal.SIGHUP, hup)
+
+    this_node = NodeInstance.NodeInstance(
+        config["node_hostname"],
+        zkhandler,
+        config,
+        logger,
+    )
+
+    # Set up the node monitoring instance and thread
+    monitoring_instance = MonitoringInstance.MonitoringInstance(
+        zkhandler, config, logger, this_node
+    )
+
+    # Tick loop; does nothing since everything is async
+    while True:
+        try:
+            sleep(1)
+        except Exception:
+            break