python-mylib/mylib/telltale.py

""" Telltale files helpers """

import argparse
import datetime
import logging
import os
import sys

from mylib import pretty_format_timedelta
from mylib.scripts.helpers import get_opts_parser, init_logging

log = logging.getLogger(__name__)

DEFAULT_WARNING_THRESHOLD = 90
DEFAULT_CRITICAL_THRESHOLD = 240


class TelltaleFile:
    """Telltale file helper class"""

    def __init__(self, filepath=None, filename=None, dirpath=None):
        assert filepath or filename, "filename or filepath is required"
        if filepath:
            assert (
                not filename or os.path.basename(filepath) == filename
            ), "filepath and filename does not match"
            assert (
                not dirpath or os.path.dirname(filepath) == dirpath
            ), "filepath and dirpath does not match"
        self.filename = filename if filename else os.path.basename(filepath)
        self.dirpath = (
            dirpath if dirpath else (os.path.dirname(filepath) if filepath else os.getcwd())
        )
        self.filepath = filepath if filepath else os.path.join(self.dirpath, self.filename)

    @property
    def last_update(self):
        """Retrieve last update datetime of the telltall file"""
        try:
            return datetime.datetime.fromtimestamp(os.stat(self.filepath).st_mtime)
        except FileNotFoundError:
            log.info("Telltale file not found (%s)", self.filepath)
        return None

    def update(self):
        """Update the telltale file"""
        log.info("Update telltale file (%s)", self.filepath)
        try:
            os.utime(self.filepath, None)
        except FileNotFoundError:
            # pylint: disable=consider-using-with
            open(self.filepath, "a", encoding="utf-8").close()

    def remove(self):
        """Remove the telltale file"""
        try:
            os.remove(self.filepath)
            return True
        except FileNotFoundError:
            return True

    @classmethod
    def check_entrypoint(
        cls,
        argv=None,
        description=None,
        default_filepath=None,
        default_warning_threshold=None,
        default_critical_threshold=None,
        fail_message=None,
        success_message=None,
    ):
        """Entry point of the script to check a telltale file last update"""
        argv = argv if argv else sys.argv
        description = description if description else "Check last execution date"
        parser = get_opts_parser(desc=description, exit_on_error=False)

        parser.add_argument(
            "-p",
            "--telltale-file-path",
            action="store",
            type=str,
            dest="telltale_file_path",
            help=f"Telltale file path (default: {default_filepath})",
            default=default_filepath,
            required=not default_filepath,
        )

        default_warning_threshold = (
            default_warning_threshold
            if default_warning_threshold is not None
            else DEFAULT_WARNING_THRESHOLD
        )
        default_critical_threshold = (
            default_critical_threshold
            if default_critical_threshold is not None
            else DEFAULT_CRITICAL_THRESHOLD
        )

        parser.add_argument(
            "-w",
            "--warning",
            type=int,
            dest="warning",
            help=(
                "Specify warning threshold (in minutes, default: "
                f"{default_warning_threshold} minutes)"
            ),
            default=default_warning_threshold,
        )

        parser.add_argument(
            "-c",
            "--critical",
            type=int,
            dest="critical",
            help=(
                "Specify critical threshold (in minutes, default: "
                f"{default_critical_threshold} minutes)"
            ),
            default=default_critical_threshold,
        )

        try:
            options = parser.parse_args(argv[1:])
        except argparse.ArgumentError as err:
            print(f"UNKNOWN - {err}")
            sys.exit(3)

        # Initialize logs
        init_logging(options, argv[0])

        telltale_file = cls(filepath=options.telltale_file_path)
        last = telltale_file.last_update
        if not last:
            status = "UNKNOWN"
            exit_code = 3
            msg = (
                fail_message
                if fail_message
                else "Fail to retrieve last successful date of execution"
            )
        else:
            delay = datetime.datetime.now() - last
            msg = (
                success_message
                if success_message
                else "Last successful execution was {last_delay} ago ({last_date})"
            ).format(
                last_delay=pretty_format_timedelta(delay),
                last_date=last.strftime("%Y/%m/%d %H:%M:%S"),
            )

            if delay >= datetime.timedelta(minutes=options.critical):
                status = "CRITICAL"
                exit_code = 2
            elif delay >= datetime.timedelta(minutes=options.warning):
                status = "WARNING"
                exit_code = 1
            else:
                status = "OK"
                exit_code = 0

        print(f"{status} - {msg}")
        sys.exit(exit_code)