#!/usr/bin/env python3 # log.py - PVC daemon logger functions # Part of the Parallel Virtual Cluster (PVC) system # # Copyright (C) 2018-2022 Joshua M. Boniface # # 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 . # ############################################################################### from collections import deque from threading import Thread from queue import Queue from datetime import datetime from time import sleep from daemon_lib.zkhandler import ZKHandler class Logger(object): # Define a logger class for a daemon instance # Keeps record of where to log, and is passed messages which are # formatted in various ways based off secondary characteristics. # ANSII colours for output fmt_red = "\033[91m" fmt_green = "\033[92m" fmt_yellow = "\033[93m" fmt_blue = "\033[94m" fmt_purple = "\033[95m" fmt_cyan = "\033[96m" fmt_white = "\033[97m" fmt_bold = "\033[1m" fmt_end = "\033[0m" last_colour = "" last_prompt = "" # Format maps format_map_colourized = { # Colourized formatting with chevron prompts (log_colours = True) "o": {"colour": fmt_green, "prompt": ">>> "}, "e": {"colour": fmt_red, "prompt": ">>> "}, "w": {"colour": fmt_yellow, "prompt": ">>> "}, "t": {"colour": fmt_purple, "prompt": ">>> "}, "i": {"colour": fmt_blue, "prompt": ">>> "}, "s": {"colour": fmt_cyan, "prompt": ">>> "}, "d": {"colour": fmt_white, "prompt": ">>> "}, "x": {"colour": last_colour, "prompt": last_prompt}, } format_map_textual = { # Uncolourized formatting with text prompts (log_colours = False) "o": {"colour": "", "prompt": "ok: "}, "e": {"colour": "", "prompt": "failed: "}, "w": {"colour": "", "prompt": "warning: "}, "t": {"colour": "", "prompt": "tick: "}, "i": {"colour": "", "prompt": "info: "}, "s": {"colour": "", "prompt": "system: "}, "d": {"colour": "", "prompt": "debug: "}, "x": {"colour": "", "prompt": last_prompt}, } # Initialization of instance def __init__(self, config): self.config = config if self.config["file_logging"]: self.logfile = self.config["log_directory"] + "/pvc.log" # We open the logfile for the duration of our session, but have a hup function self.writer = open(self.logfile, "a", buffering=0) self.last_colour = "" self.last_prompt = "" if self.config["zookeeper_logging"]: self.zookeeper_queue = Queue() self.zookeeper_logger = ZookeeperLogger(self.config, self.zookeeper_queue) self.zookeeper_logger.start() # Provide a hup function to close and reopen the writer def hup(self): self.writer.close() self.writer = open(self.logfile, "a", buffering=0) # Provide a termination function so all messages are flushed before terminating the main daemon def terminate(self): if self.config["file_logging"]: self.writer.close() if self.config["zookeeper_logging"]: self.out("Waiting for Zookeeper message queue to drain", state="s") tick_count = 0 while not self.zookeeper_queue.empty(): sleep(0.5) tick_count += 1 if tick_count > 30: break self.zookeeper_logger.stop() self.zookeeper_logger.join() # Output function def out(self, message, state=None, prefix=""): # Get the date if self.config["log_dates"]: date = "{} ".format(datetime.now().strftime("%Y/%m/%d %H:%M:%S.%f")) else: date = "" # Get the format map if self.config["log_colours"]: format_map = self.format_map_colourized endc = Logger.fmt_end else: format_map = self.format_map_textual endc = "" # Define an undefined state as 'x'; no date in these prompts if not state: state = "x" date = "" # Get colour and prompt from the map colour = format_map[state]["colour"] prompt = format_map[state]["prompt"] # Append space and separator to prefix if prefix != "": prefix = prefix + " - " # Assemble message string message = colour + prompt + endc + date + prefix + message # Log to stdout if self.config["stdout_logging"]: print(message) # Log to file if self.config["file_logging"]: self.writer.write(message + "\n") # Log to Zookeeper if self.config["zookeeper_logging"]: self.zookeeper_queue.put(message) # Set last message variables self.last_colour = colour self.last_prompt = prompt class ZookeeperLogger(Thread): """ Defines a threaded writer for Zookeeper locks. Threading prevents the blocking of other daemon events while the records are written. They will be eventually-consistent """ def __init__(self, config, zookeeper_queue): self.config = config self.node = self.config["node"] self.max_lines = self.config["node_log_lines"] self.zookeeper_queue = zookeeper_queue self.connected = False self.running = False self.zkhandler = None Thread.__init__(self, args=(), kwargs=None) def start_zkhandler(self): # We must open our own dedicated Zookeeper instance because we can't guarantee one already exists when this starts if self.zkhandler is not None: try: self.zkhandler.disconnect() except Exception: pass while True: try: self.zkhandler = ZKHandler(self.config, logger=None) self.zkhandler.connect(persistent=True) break except Exception: sleep(0.5) continue self.connected = True # Ensure the root keys for this are instantiated self.zkhandler.write([("base.logs", ""), (("logs", self.node), "")]) def run(self): self.start_zkhandler() self.running = True while self.running: # Get a new message try: message = self.zookeeper_queue.get(timeout=1) if not message: continue except Exception: continue if not self.config["log_dates"]: # We want to log dates here, even if the log_dates config is not set date = "{} ".format(datetime.now().strftime("%Y/%m/%d %H:%M:%S.%f")) else: date = "" try: with self.zkhandler.writelock(("logs.messages", self.node)): # Get the logs that are currently in Zookeeper and populate our deque cur_logs = self.zkhandler.read(("logs.messages", self.node)) if cur_logs is None: cur_logs = "" logs = deque(cur_logs.split("\n"), self.max_lines - 1) # Add the message to the deque logs.append(f"{date}{message}") # Write the updated messages into Zookeeper self.zkhandler.write( [(("logs.messages", self.node), "\n".join(logs))] ) except Exception: continue return def stop(self): self.running = False