If you for some reason can not use docker and don't want to pollute your system globally with cpan packages, you can use a locallib install instead. CentOS example:

  sudo yum -y install postgresql-devel   
  sudo useradd -d /home/pgsqltun -m -s /bin/bash -c"pgsql tuner user"  psqltun
  sudo su - psqltun   
  wget -O- https://cpanmin.us | perl - -l $HOME/perl5 App::cpanminus local::lib
  echo 'eval `perl -I $HOME/perl5/lib/perl5 -Mlocal::lib`' >> $HOME/.bash_profile
  echo 'export MANPATH=$HOME/perl5/man:$MANPATH' >> $HOME/.bash_profile
  . .bash_profile
  cpanm DBD::Pg
  <install postgresqltuner.pl>