What are all of the users and groups in a base RHEL installation?

Diagnostic Steps

1. On the matching version RHEL machine switch to a directory with at least 100G of space:

   cd _/path/to/large/volume_
   

2. Download RHEL DVD iso from https://access.redhat.com/downloads/ to your current directory.

3. Download and install a basic set of packages and their dependencies required for functional use of chroot:

   yumdownloader --resolve --alldeps --downloaddir ./pkgs redhat-release filesystem setup glibc bash coreutils dnf strace
   dnf install strace -y
   time strace -qfTttvys 192 -e trace=read,execve -o ./rpm-strace-minimal-package-set-filtered-read-execve.txt rpm -iv --root `pwd`/fakeroot ./pkgs/*
   

4. Obtain a first set of users and groups installed by the basic set of packages:

   grep "read(.*\.rpm>\|execve(.*\(\"/\(usr/sbin\|sbin\)/\(useradd\|adduser\|newusers\|usermod\)\"\|\"/\(usr/sbin\|sbin\)/\(groupadd\|groupmems\|groupmod\)\"\)" ./rpm-strace-minimal-package-set-filtered-read-execve.txt | sed -e "s#^[0-9]\+[ ]\+.*read([0-9]\+<.*/\(.*\.rpm\)>.*#\1#" > ./partial-results-minimal-package-set-grep-read-execve-sed-get-rpm-filename.txt
   
   uniq ./partial-results-minimal-package-set-grep-read-execve-sed-get-rpm-filename.txt | grep execve -B 1 > ./partial-results-minimal-package-set-uniq-grep-execve-B-1.txt 
   
   sed -e "s#^[0-9]\+[ ]\+.*execve(\(\"/\(usr/sbin\|sbin\)/\(useradd\|adduser\|newusers\|usermod\)\"\|\"/\(usr/sbin\|sbin\)/\(groupadd\|groupmems\|groupmod\)\"\).* \[\(.*\)\], \[\"[A-Z_]\+.*#\6#" -e "s#[,]##g" ./partial-results-minimal-package-set-uniq-grep-execve-B-1.txt > ./final-results-minimal-package-set.txt
   

5. Set up a yum ISO repository:

   cat > ./fakeroot/etc/yum.repos.d/media.repo <<MEDIA.REPO_EOF
   [InstallMedia-BaseOS]
   name=Red Hat Enterprise Linux BaseOS
   mediaid=None
   metadata_expire=-1
   gpgcheck=0
   cost=500
   enabled=1
   baseurl=file:///mnt/rhel_iso/BaseOS/
   
   [InstallMedia-AppStream]
   name=Red Hat Enterprise Linux AppStream
   mediaid=None
   metadata_expire=-1
   gpgcheck=0
   cost=500
   enabled=1
   baseurl=file:///mnt/rhel_iso/AppStream/
   MEDIA.REPO_EOF
   
   chmod 644 ./fakeroot/etc/yum.repos.d/media.repo; \
   
   mkdir -p ./fakeroot/mnt/rhel_iso
   

6. Get into chroot and mount the ISO:

   • Download chroot-fakeroot.sh and make it executable:

     chmod +x ./chroot-fakeroot.sh
     

     • On RHEL 8:

       mv ./RHEL-8.7.0-20221013.1-x86_64-dvd1.iso ./fakeroot/root/
       ./chroot-fakeroot.sh -r ./fakeroot/
       mount -o loop ~/RHEL-8.7.0-20221013.1-x86_64-dvd1.iso /mnt/rhel_iso/
       cd
       

     • On RHEL 9:

       mv ./RHEL-9.1.0-20221027.3-x86_64-dvd1.iso ./fakeroot/root/
       

       ./chroot-fakeroot.sh -r ./fakeroot/
       mount -o loop ~/RHEL-9.1.0-20221027.3-x86_64-dvd1.iso /mnt/rhel_iso/
       cd

7. Install all packages under chroot:

   dnf -y module enable \*
   
   time strace -qfTttvys 192 -e trace=read,execve -o yum-strace-filtered-read-execve.txt dnf -y --skip-broken install \*
   
   grep "read(.*\.rpm>\|execve(.*\(\"/\(usr/sbin\|sbin\)/\(useradd\|adduser\|newusers\|usermod\)\"\|\"/\(usr/sbin\|sbin\)/\(groupadd\|groupmems\|groupmod\)\"\)" yum-strace-filtered-read-execve.txt | sed -e "s#^[0-9]\+[ ]\+.*read([0-9]\+<.*/\(.*\.rpm\)>.*#\1#" > partial-results-grep-read-execve-sed-get-rpm-filename.txt
   
   uniq partial-results-grep-read-execve-sed-get-rpm-filename.txt | grep execve -B 1 > partial-results-uniq-grep-execve-B-1.txt
   
   sed -e "s#^[0-9]\+[ ]\+.*execve(\(\"/\(usr/sbin\|sbin\)/\(useradd\|adduser\|newusers\|usermod\)\"\|\"/\(usr/sbin\|sbin\)/\(groupadd\|groupmems\|groupmod\)\"\).* \[\(.*\)\], \[\"[A-Z_]\+.*#\6#" -e "s#[,]##g" partial-results-uniq-grep-execve-B-1.txt > final-results.txt
   
   exit
   

8. Combine the users and groups added while creating the chroot environment and those installed while running under chroot, as well as adding results for conflicting packages:

   • On RHEL 8:

     cat ./final-results-minimal-package-set.txt > ./full-final-results.txt
     
     cat ./fakeroot/root/final-results.txt >> ./full-final-results.txt
     
     cat >> ./full-final-results.txt <<CONFLICTS_OR_MISSING_RHEL8_EOF
     --
     mysql-server-8.0.30-1.module+el8.6.0+16523+5cb0e868.x86_64.rpm
     "/usr/sbin/groupadd" "-g" "27" "-o" "-r" "mysql"
     "/usr/sbin/useradd" "-M" "-N" "-g" "mysql" "-o" "-r" "-d" "/var/lib/mysql" "-s" "/sbin/nologin" "-c" "MySQL Server" "-u" "27" "mysql"
     --
     dnsmasq-2.79-24.el8.x86_64.rpm
     "/usr/sbin/groupadd" "-r" "dnsmasq"
     "useradd" "-r" "-g" "dnsmasq" "-d" "/var/lib/dnsmasq" "-s" "/usr/sbin/nologin" "-c" "Dnsmasq DHCP and DNS server" "dnsmasq"
     CONFLICTS_OR_MISSING_RHEL8_EOF
     

   • On RHEL 9:

     cat >> ./full-final-results.txt <<CONFLICTS_OR_MISSING_RHEL9_EOF
     --
     mysql-server-8.0.30-3.el9_0.x86_64.rpm
     "/usr/sbin/groupadd" "-g" "27" "-o" "-r" "mysql"
     "/usr/sbin/useradd" "-M" "-N" "-g" "mysql" "-o" "-r" "-d" "/var/lib/mysql" "-s" "/sbin/nologin" "-c" "MySQL Server" "-u" "27" "mysql"
     --
     dnsmasq-2.85-5.el9.x86_64.rpm
     "/usr/sbin/groupadd" "-r" "dnsmasq"
     "useradd" "-r" "-g" "dnsmasq" "-d" "/var/lib/dnsmasq" "-s" "/usr/sbin/nologin" "-c" "Dnsmasq DHCP and DNS server" "dnsmasq"
     CONFLICTS_OR_MISSING_RHEL9_EOF
     

9. Parse the results:

   • Download parse-results.sh and make it executable:

     chmod +x ./parse-results.sh
     

     • On RHEL 8:

       cat full-final-results.txt | ./parse-results.sh > current-results-RHEL-8.7.iso.txt
       

     • On RHEL 9:

       cat full-final-results.txt | ./parse-results.sh > current-results-RHEL-9.1.iso.txt