Modified yumhelper for centos8

yumhelper.py

# Python helper script to query for the packages that have
# pending updates. Called by the yum package provider
#
# (C) 2007 Red Hat Inc.
# David Lutterkort <dlutter @redhat.com>
#
# cparker modified to work with python 3 on centos 8

import sys
import string
import re

# this maintains compatibility with really old platforms with python 1.x
from os import popen, WEXITSTATUS

# Try to use the yum libraries by default, but shell out to the yum executable
# if they are not present (i.e. yum <= 2.0). This is only required for RHEL3
# and earlier that do not support later versions of Yum. Once RHEL3 is EOL,
# shell_out() and related code can be removed.
###
# (Interestingly, the shell_out stuff is what makes it work with RHEL8)

OVERRIDE_OPTS = {
    'debuglevel': 0,
    'errorlevel': 0,
    'logfile': '/dev/null'
}

enable = []
disable = []
args = list(sys.argv)

while len(args) > 0:
    a = args.pop(0)
    if a == "-d":
        next = args.pop(0)
        disable.extend( next.split(",") )
    if a == "-e":
        next = args.pop(0)
        enable.extend( next.split(",") )

def shell_out():
    try:
        repostring = ""
        if disable:
            repostring += " '--disablerepo=%s'" % ",".join(disable)
        if enable:
            repostring += " '--disablerepo=%s'" % ",".join(enable)
        p = popen("/usr/bin/env yum%s check-update 2>&1" % repostring)
        output = p.readlines()
        rc = p.close()

        if rc is not None:
            # None represents exit code of 0, otherwise the exit code is in the
            # format returned by wait(). Exit code of 100 from yum represents
            # updates available.
            if WEXITSTATUS(rc) != 100:
                return WEXITSTATUS(rc)
        else:
            # Exit code is None (0), no updates waiting so don't both parsing output
            return 0

        # Yum prints a line of hyphens (old versions) or a blank line between
        # headers and package data, so skip everything before them
        skipheaders = 0
        for line in output:
            if not skipheaders:
                if re.compile("^((-){80}|)$").search(line):
                    skipheaders = 1
                continue

            # Skip any blank lines
            if re.compile("^[ \t]*$").search(line):
                continue
            #ignore everything after Obsoleting
            if re.compile("^Obsoleting").search(line):
                return 0
            # Format is:
            # Yum 1.x: name arch (epoch:)?version
            # Yum 2.0: name arch (epoch:)?version repo
            # epoch is optional if 0

            p = str.split(line)
            na = p[0]
            pevr = p[1]
            p = str.split(na,'.')
            pname = p[0]
            parch = p[1]

            # Separate out epoch:version-release
            evr_re = re.compile("^(\d:)?(\S+)-(\S+)$")
            evr = evr_re.match(pevr)
            pepoch = ""
            if evr.group(1) is None:
                pepoch = "0"
            else:
                pepoch = evr.group(1).replace(":", "")
            pversion = evr.group(2)
            prelease = evr.group(3)

            print("_pkg", pname, pepoch, pversion, prelease, parch)

        return 0
    except:
        print (sys.exc_info()[0])
        return 1

rc = shell_out()
sys.exit(rc)