librenms-librenms/LibreNMS/library.py

#! /usr/bin/env python3
#  -*- coding: utf-8 -*-

import sys
import os
import logging
import tempfile
import subprocess
import threading
import time
from logging.handlers import RotatingFileHandler

try:
    import MySQLdb
except ImportError:
    try:
        import pymysql

        pymysql.install_as_MySQLdb()
        import MySQLdb
    except ImportError as exc:
        print("ERROR: missing the mysql python module please run:")
        print("pip install -r requirements.txt")
        print("ERROR: %s" % exc)
        sys.exit(2)

logger = logging.getLogger(__name__)

# Logging functions ########################################################

FORMATTER = logging.Formatter("%(asctime)s :: %(levelname)s :: %(message)s")


def logger_get_console_handler():
    try:
        console_handler = logging.StreamHandler(sys.stdout)
    except OSError as exc:
        print("Cannot log to stdout, trying stderr. Message %s" % exc)
        try:
            console_handler = logging.StreamHandler(sys.stderr)
            console_handler.setFormatter(FORMATTER)
            return console_handler
        except OSError as exc:
            print("Cannot log to stderr neither. Message %s" % exc)
            return False
    else:
        console_handler.setFormatter(FORMATTER)
        return console_handler


def logger_get_file_handler(log_file):
    err_output = None
    try:
        file_handler = RotatingFileHandler(
            log_file, mode="a", encoding="utf-8", maxBytes=1024000, backupCount=3
        )
    except OSError as exc:
        try:
            print(
                "Cannot create logfile. Trying to obtain temporary log file.\nMessage: %s"
                % exc
            )
            err_output = str(exc)
            temp_log_file = tempfile.gettempdir() + os.sep + __name__ + ".log"
            print("Trying temporary log file in " + temp_log_file)
            file_handler = RotatingFileHandler(
                temp_log_file,
                mode="a",
                encoding="utf-8",
                maxBytes=1000000,
                backupCount=1,
            )
            file_handler.setFormatter(FORMATTER)
            err_output += "\nUsing [%s]" % temp_log_file
            return file_handler, err_output
        except OSError as exc:
            print(
                "Cannot create temporary log file either. Will not log to file. Message: %s"
                % exc
            )
            return False
    else:
        file_handler.setFormatter(FORMATTER)
        return file_handler, err_output


def logger_get_logger(log_file=None, temp_log_file=None, debug=False):
    # If a name is given to getLogger, than modules can't log to the root logger
    _logger = logging.getLogger()
    if debug is True:
        _logger.setLevel(logging.DEBUG)
    else:
        _logger.setLevel(logging.INFO)
    console_handler = logger_get_console_handler()
    if console_handler:
        _logger.addHandler(console_handler)
    if log_file is not None:
        file_handler, err_output = logger_get_file_handler(log_file)
        if file_handler:
            _logger.addHandler(file_handler)
            _logger.propagate = False
            if err_output is not None:
                print(err_output)
                _logger.warning(
                    "Failed to use log file [%s], %s.", log_file, err_output
                )
    if temp_log_file is not None:
        if os.path.isfile(temp_log_file):
            try:
                os.remove(temp_log_file)
            except OSError:
                logger.warning("Cannot remove temp log file [%s]." % temp_log_file)
        file_handler, err_output = logger_get_file_handler(temp_log_file)
        if file_handler:
            _logger.addHandler(file_handler)
            _logger.propagate = False
            if err_output is not None:
                print(err_output)
                _logger.warning(
                    "Failed to use log file [%s], %s.", log_file, err_output
                )
    return _logger


# Generic functions ########################################################


def check_for_file(file):
    try:
        with open(file) as f:
            pass
    except IOError as exc:
        logger.error("Oh dear... %s does not seem readable" % file)
        logger.debug("ERROR:", exc_info=True)
        sys.exit(2)


# Config functions #########################################################


def get_config_data(install_dir):
    config_cmd = ["/usr/bin/env", "php", "%s/config_to_json.php" % install_dir]
    try:
        proc = subprocess.Popen(
            config_cmd, stdout=subprocess.PIPE, stdin=subprocess.PIPE
        )
        return proc.communicate()[0].decode()
    except Exception as e:
        print("ERROR: Could not execute: %s" % config_cmd)
        print(e)
        sys.exit(2)


# Database functions #######################################################


def db_open(db_socket, db_server, db_port, db_username, db_password, db_dbname):
    try:
        options = dict(
            host=db_server,
            port=int(db_port),
            user=db_username,
            passwd=db_password,
            db=db_dbname,
        )

        if db_socket:
            options["unix_socket"] = db_socket

        return MySQLdb.connect(**options)
    except Exception as dbexc:
        print("ERROR: Could not connect to MySQL database!")
        print("ERROR: %s" % dbexc)
        sys.exit(2)