RedHat 8 and CentOS 8 support

perl-PDF-API2 is not needed since STOR2RRD v7.80+

RHEL8 and CentOS8 standard repositories do not contain perl-PDF-API2 and net-snmp-perl packages with their dependencies.
You have to download and install them manually.

Manual install

Download net-snmp-perl
Site: pkgs.org/download/net-snmp ➡ CentOS8 ➡ OKey x86_64
repo.okay.com.mx/centos/8/x86_64/release//net-snmp-perl-5.8-7.el8.2.x86_64.rpm
repo.okay.com.mx/centos/8/x86_64/release//net-snmp-5.8-7.el8.2.x86_64.rpm
repo.okay.com.mx/centos/8/x86_64/release//net-snmp-utils-5.8-7.el8.2.x86_64.rpm
repo.okay.com.mx/centos/8/x86_64/release//net-snmp-agent-libs-5.8-7.el8.2.x86_64.rpm
repo.okay.com.mx/centos/8/x86_64/release//net-snmp-libs-5.8-7.el8.2.x86_64.rpm

perl-PDF-API2 (when it does not work use CPAN method bellow)
Site: www.city-fan.org/ftp/contrib/yum-repo/rhel8/x86_64/
www.city-fan.org/ftp/contrib/yum-repo/rhel8/x86_64/perl-Graphics-TIFF-6-4.el8.x86_64.rpm
www.city-fan.org/ftp/contrib/yum-repo/rhel8/x86_64/perl-PDF-API2-2.033-6.el8.noarch.rpm
www.city-fan.org/ftp/contrib/yum-repo/rhel8/x86_64/perl-Font-TTF-1.06-8.el8.noarch.rpm

Installation
RHEL 8: enable the codeready-builder-for-rhel-8-*-rpms repository

# ARCH=$( /bin/arch )
# subscription-manager repos --enable "codeready-builder-for-rhel-8-${ARCH}-rpms"

# yum config-manager --set-enabled PowerTools
or
# dnf config-manager --set-enabled powertools

Remove SNMP packages if they are installed:

# rpm -qa| grep snmp
  net-snmp-agent-libs-5.8-7.el8.2.x86_64
  net-snmp-utils-5.8-7.el8.2.x86_64
  net-snmp-libs-5.8-7.el8.2.x86_64
  net-snmp-5.8-7.el8.2.x86_64

# yum remove net-snmp net-snmp-libs net-snmp-agent-libs net-snmp-utils

Install standard packages from RHEL8 repositores

# umask 0022
# yum install perl rrdtool rrdtool-perl httpd
# yum install epel-release ed bc sharutils
# yum install perl-TimeDate perl-XML-Simple perl-XML-SAX perl-XML-LibXML perl-Env perl-CGI perl-Data-Dumper perl-LWP-Protocol-https perl-libwww-perl libxml2

Install SNMP and PDF support packages already downloaded localy:

# yum install net-snmp-perl-5.8-7.el8.2.x86_64.rpm net-snmp-5.8-7.el8.2.x86_64.rpm net-snmp-utils-5.8-7.el8.2.x86_64.rpm net-snmp-libs-5.8-7.el8.2.x86_64.rpm net-snmp-agent-libs-5.8-7.el8.2.x86_64.rpm
# yum install perl-PDF-API2-2.033-6.el8.noarch.rpm perl-Font-TTF-1.06-8.el8.noarch.rpm perl-Graphics-TIFF-6-4.el8.x86_64.rpm

CPAN install of PDF::API2

# Prerequsites
umask 022
yum makecache
yum install perl-CPAN
yum install rpm
yum install gcc make
cpan App::cpanminus

# Check if is installed module Compress::Zlib :
cpan -l | grep -i Compress::Zlib
  Loading internal null logger. Install Log::Log4perl for logging messages
  Compress::Zlib    2.081
  IO::Compress::Zlib::Constants    2.081
  IO::Compress::Zlib::Extra    2.081

# Check if module PDF::API2: is available
cpan -l | grep -i PDF::API2
  Loading internal null logger. Install Log::Log4perl for logging messages
  PDF::API2    2.043

# Installing it
cpan PDF::API2
  Loading internal null logger. Install Log::Log4perl for logging messages
  Reading '/root/.cpan/Metadata'
  Database was generated on Thu, 16 Dec 2021 13:17:02 GMT
  CPAN: Module::CoreList loaded ok (v5.20181130)
  PDF::API2 is up to date (2.043).