#!/bin/bash
# 
# migrate2rocky - Migrate another EL8 distribution to RockyLinux 8.
# By: Peter Ajamian <peter@pajamian.dhs.org>
# Adapted from centos2rocky.sh by label <label@rockylinux.org>
#
# The latest version of this script can be found at:
# https://github.com/rocky-linux/rocky-tools
#
# Copyright (c) 2021 Rocky Enterprise Software Foundation
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice (including the next
# paragraph) shall be included in all copies or substantial portions of the
# Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#

## Using this script means you accept all risks of system instability.

# These checks need to be right at the top because we start with bash-isms right
# away in this script.
if [ -n "$POSIXLY_CORRECT" ] || [ -z "$BASH_VERSION" ]; then
    printf '%s\n' "bash >= 4.2 is required for this script." >&2
    exit 1
fi

# We need bash version >= 4.2 for associative arrays and other features.
if (( BASH_VERSINFO[0]*100 + BASH_VERSINFO[1] < 402 )); then
    printf '%s\n' "bash >= 4.2 is required for this script." >&2
    exit 1
fi

# Make sure we're root.
if (( EUID != 0 )); then
    printf '%s\n' \
        "You must run this script as root.  Either use sudo or 'su -c ${0}'" >&2
    exit 1
fi


# Path to logfile
logfile=/var/log/migrate2rocky.log

# Rotate old logs
numlogs=5
if [[ -e $logfile ]]; then
    # Here we use mv before bin_check, so simply check the exit status to see if
    # it worked.
    if ! mv -f "$logfile" "$logfile.0"; then
        printf '%s\n' "Unable to rotate logfiles, continuing without rotation." >&2
    else
        for ((i=numlogs;i>0;i--)); do
            if [[ -e "$logfile.$((i-1))" ]]; then
                if ! mv -f "$logfile.$((i-1))" "$logfile.$i"; then
                    printf '%s\n' \
"Unable to rotate logfiles, continuing without rotation."
                    break
                fi
            fi
        done
    fi
fi

# Send all output to the logfile as well as stdout.
# After the following we get:
# Output to 1 goes to stdout and the logfile.
# Output to 2 goes to stderr and the logfile.
# Output to 3 just goes to stdout.
# Output to 4 just goes to stderr.
# Output to 5 just goes to the logfile.

# shellcheck disable=SC2094
exec \
    3>&1 \
    4>&2 \
    5>> "$logfile" \
    > >(tee -a "$logfile") \
    2> >(tee -a "$logfile" >&2)

# List nocolor last here so that -x doesn't bork the display.
errcolor=$(tput setaf 1)
infocolor=$(tput setaf 6)
nocolor=$(tput op)

# Single arg just gets returned verbatim, multi arg gets formatted via printf.
# First arg is the name of a variable to store the results.
msg_format () {
    local _var
    _var="$1"
    shift
    if (( $# > 1 )); then
        # shellcheck disable=SC2059
        printf -v "$_var" "$@"
    else
        printf -v "$_var" "%s" "$1"
    fi
}

# Send an info message to the log file and stdout (with color)
infomsg () {
    local msg
    msg_format msg "$@"
    printf '%s' "$msg" >&5
    printf '%s%s%s' "$infocolor" "$msg" "$nocolor" >&3
}

# Send an error message to the log file and stderr (with color)
errmsg () {
    local msg
    msg_format msg "$@"
    printf '%s' "$msg" >&5
    printf '%s%s%s' "$errcolor" "$msg" "$nocolor" >&4
}

infomsg 'migrate2rocky - Begin logging at %(%c)T.\n\n' -1

export LC_ALL=C.UTF-8
unset LANGUAGE
shopt -s nullglob

SUPPORTED_MAJOR="8"
SUPPORTED_PLATFORM="platform:el$SUPPORTED_MAJOR"
ARCH=$(arch)

gpg_key_url="https://dl.rockylinux.org/pub/rocky/RPM-GPG-KEY-rockyofficial"
gpg_key_sha512="88fe66cf0a68648c2371120d56eb509835266d9efdf7c8b9ac8fc101bdf1f0e0197030d3ea65f4b5be89dc9d1ef08581adb068815c88d7b1dc40aa1c32990f6a"

sm_ca_dir=/etc/rhsm/ca
unset tmp_sm_ca_dir

# all repos must be signed with the same key given in $gpg_key_url
declare -A repo_urls
repo_urls=(
    [rockybaseos]="https://dl.rockylinux.org/pub/rocky/${SUPPORTED_MAJOR}/BaseOS/$ARCH/os/"
    [rockyappstream]="https://dl.rockylinux.org/pub/rocky/${SUPPORTED_MAJOR}/AppStream/$ARCH/os/"
)

# These are additional packages that should always be installed.
# (currently blank, but we add to it for an EFI boot system).
always_install=()

# The repos package for CentOS stream requires special handling.
declare -g -A stream_repos_pkgs
stream_repos_pkgs=(
    [rocky-repos]=centos-stream-repos
    [epel-release]=epel-next-release
)

# Map for package name suffix for shim/grub2-efi
# on x86_64: grub2-efi-x64, shim-x64
# on aarch64: grub2-efi-aa64, shim-aa64
declare -A cpu_arch_suffix_map=(
    [x86_64]=x64
    [aarch64]=aa64
)

# Prefix to add to CentOS stream repo names when renaming them.
stream_prefix=stream-

# Always replace these stream packages with their Rocky Linux equivalents.
stream_always_replace=(
    fwupdate\*
    grub2-\*
    shim-\*
    kernel
    kernel-\*
)

# Directory to required space in MiB
declare -A dir_space_map
dir_space_map=(
    [/usr]=250
    [/var]=1536
    [/boot]=50
)

unset CDPATH

exit_message() {
  errmsg $'\n'"$1"$'\n\n'
  final_message
  exit 1
}

final_message() {
    errmsg '%s ' \
        "An error occurred while we were attempting to convert your system to" \
        "Rocky Linux. Your system may be unstable. Script will now exit to" \
        "prevent possible damage."$'\n\n'
    logmessage
}

logmessage(){
    printf '%s%s%s\n' "$infocolor" \
        "A log of this installation can be found at $logfile" \
        "$nocolor" >&3
}

# This just grabs a field from os-release and returns it.
os-release () (
    . /etc/os-release
    if ! [[ ${!1} ]]; then
        return 1
    fi
    printf '%s\n' "${!1}"
)

# Check the version of a package against a supplied version number.  Note that
# this uses sort -V to compare the versions which isn't perfect for rpm package
# versions, but to do a proper comparison we would need to use rpmdev-vercmp in
# the rpmdevtools package which we don't want to force-install.  sort -V should
# be adequate for our needs here.
pkg_ver() (
    ver=$(rpm -q --qf '%{VERSION}\n' "$1") || return 2
    if [[ $(sort -V <<<"$ver"$'\n'"$2" | head -1) != "$2" ]]; then
        return 1
    fi
    return 0
)

# Set up a temporary directory.
pre_setup () {
    if ! tmp_dir=$(mktemp -d) || [[ ! -d "$tmp_dir" ]]; then
        exit_message "Error creating temp dir"
    fi
    # failglob makes pathname expansion fail if empty, dotglob adds files
    # starting with . to pathname expansion
    if ( shopt -s failglob dotglob; : "$tmp_dir"/* ) 2>/dev/null ; then
        exit_message "Temp dir not empty"
    fi
}

# Cleanup function gets rid of the temporary directory.
exit_clean () {
    if [[ -d "$tmp_dir" ]]; then
        rm -rf "$tmp_dir"
    fi
    if [[ -f "$container_macros" ]]; then
        rm -f "$container_macros"
    fi
}

pre_check () {
    if [[ -e /etc/rhsm/ca/katello-server-ca.pem ]]; then
# shellcheck disable=SC2026
        exit_message \
'Migration from Katello-modified systems is not supported by migrate2rocky. '\
'See the README file for details.'
    fi
    if [[ -e /etc/salt/minion.d/susemanager.conf ]]; then
# shellcheck disable=SC2026
        exit_message \
'Migration from Uyuni/SUSE Manager-modified systems is not supported by '\
'migrate2rocky. See the README file for details.'
    fi

    # Get available space to compare to requirements.
    # If the stock kernel is not installed we don't require space in /boot
    if ! rpm -q --quiet kernel; then 
	dir_space_map[/boot]=0
    fi
    local -a errs dirs=("${!dir_space_map[@]}")
    local dir mount avail i=0
    local -A mount_avail_map dir_mount_map mount_space_map
    while read -r mount avail; do 
	if [[ $mount == 'Filesystem' ]]; then
	    continue
	fi

	dir=${dirs[$((i++))]}

	dir_mount_map[$dir]=$mount
	mount_avail_map[$mount]=${avail%M}
	(( mount_space_map[$mount]+=dir_space_map[$dir] ))
    done < <(df -BM --output=source,avail "${dirs[@]}")

    for mount in "${!mount_space_map[@]}"; do
	(( avail = mount_avail_map[$mount]*95/100 ))
	if (( avail < mount_space_map[$mount] )); then
	    errs+=("Not enough space in $mount, ${mount_space_map[$mount]}M required, ${avail}M available.")
	fi
    done

    if (( ${#errs[@]} )); then
	IFS=$'\n'
	exit_message "${errs[*]}"
    fi
}

# All of the binaries used by this script are available in a EL8 minimal install
# and are in /bin, so we should not encounter a system where the script doesn't
# work unless it's severely broken.  This is just a simple check that will cause
# the script to bail if any expected system utilities are missing.
bin_check() {
    # Check the platform.
    if [[ $(os-release PLATFORM_ID) != "$SUPPORTED_PLATFORM" ]]; then
# shellcheck disable=SC2026
        exit_message \
'This script must be run on an EL8 distribution.  Migration from other '\
'distributions is not supported.'
    fi

    local -a missing bins
    bins=(
        rpm dnf awk column tee tput mkdir cat arch sort uniq rmdir df
        rm head curl sha512sum mktemp systemd-detect-virt sed grep
    )
    if [[ $update_efi ]]; then
        bins+=(findmnt grub2-mkconfig efibootmgr mokutil lsblk)
    fi
    for bin in "${bins[@]}"; do
        if ! type "$bin" >/dev/null 2>&1; then
            missing+=("$bin")
        fi
    done

    local -A pkgs
    pkgs=(
        [dnf]=4.2
        [dnf-plugins-core]=0
    )

    for pkg in "${!pkgs[@]}"; do
        ver=${pkgs[$pkg]}
        if ! pkg_ver "$pkg" "$ver"; then
            # shellcheck disable=SC2140
            exit_message \
"$pkg >= $ver is required for this script.  Please run "\
"\"dnf install $pkg; dnf update\" first."
        fi
    done;

    if (( ${#missing[@]} )); then
# shellcheck disable=SC2140
        exit_message \
"Commands not found: ${missing[*]}.  Possible bad PATH setting or corrupt "\
"installation."
    fi
}

# This function will overwrite the repoquery_results associative array with the
# info for the resulting package.  Note that we explicitly disable the epel repo
# as a special-case below to avoid having the extras repository map to epel.
repoquery () {
    local name val prev result
    result=$(
        dnf -y -q --setopt=epel.excludepkgs=epel-release repoquery -i "$1" ||
            exit_message "Failed to fetch info for package $1."
    )
    if ! [[ $result ]]; then
        # We didn't match this package, the repo could be disabled.
        return 1
    fi
    declare -gA repoquery_results=()
    while IFS=" :" read -r name val; do
        if [[ -z $name ]]; then
            repoquery_results[$prev]+=" $val"
        else
            prev=$name
            repoquery_results[$name]=$val
        fi
    done <<<"$result"
}

# This function will overwrite the repoinfo_results associative array with the
# info for the resulting repository.
repoinfo () {
    local name val result
    result=$(dnf -y -q repoinfo "$1") ||
            exit_message "Failed to fetch info for repository $1."
    if [[ $result == 'Total packages: 0' ]]; then
        # We didn't match this repo.
        return 1
    fi
    declare -gA repoinfo_results=()
    while IFS=" :" read -r name val; do
        if [[ ! ( $name || $val) ]]; then
            continue
        fi
        if [[ -z $name ]]; then
            repoinfo_results[$prev]+=" $val"
        else
            prev=$name
            repoinfo_results[$name]=$val
        fi
    done <<<"$result"

    # dnf repoinfo doesn't return the gpgkey, but we need that so we have to get
    # it from the repo file itself.
    # "end_of_file" is a hack here.  Since it is not a valid dnf setting we know
    # it won't appear in a .repo file on a line by itself, so it's safe to
    # search for the string to make the awk parser look all the way to the end
    # of the file.
    # shellcheck disable=SC2154
    repoinfo_results[Repo-gpgkey]=$(
        awk '
            $0=="['"${repoinfo_results[Repo-id]}"']",$0=="end_of_file" {
                if (l++ < 1) {next}
                else if (/^\[.*\]$/) {nextfile}
                else if (sub(/^gpgkey\s*=\s*file:\/\//,"")) {print; nextfile}
                else {next}
            }
        ' < "${repoinfo_results[Repo-filename]}"
    )

    # Add an indicator of whether this is a subscription-manager managed
    # repository.
    # shellcheck disable=SC2154
    repoinfo_results[Repo-managed]=$(
        awk '
            BEGIN {FS="[)(]"}
            /^# Managed by \(.*\) subscription-manager$/ {print $2}
        ' < "${repoinfo_results[Repo-filename]}"
    )
}

provides_pkg () (
    if [[ ! $1 ]]; then
        return 0
    fi

    set -o pipefail
    provides=$(dnf -y -q provides "$1" | awk '{print $1; nextfile}') ||
        return 1
    set +o pipefail
    pkg=$(rpm -q --queryformat '%{NAME}\n' "$provides") ||
            pkg=$(dnf -y -q repoquery --queryformat '%{NAME}\n' "$provides") ||
            exit_message "Can't get package name for $provides."
    printf '%s\n' "$pkg"
)

# If you pass an empty arg as one of the package specs to rpm it will match
# every package on the system.  This function simply strips out any empty args
# and passes the rest to rpm to avoid this side-effect.
saferpm () (
    args=()
    for a in "$@"; do
        if [[ $a ]]; then
            args+=("$a")
        fi
    done
    rpm "${args[@]}"
)

# And a similar function for dnf
safednf () (
    args=()
    for a in "$@"; do
        if [[ $a ]]; then
            args+=("$a")
        fi
    done
    dnf "${args[@]}"
)

collect_system_info () {
    # Dump the DNF cache first so we start with a clean slate.
    infomsg $'\nRemoving dnf cache\n'
    rm -rf /var/cache/{yum,dnf}
    # Check the efi mount first, so we can bail before wasting time on all these
    # other checks if it's not there.
    if [[ $update_efi ]]; then
        local efi_mount kname
        declare -g -a efi_disk efi_partition
        efi_mount=$(findmnt --mountpoint /boot/efi --output SOURCE \
            --noheadings) ||
            exit_message "Can't find EFI mount.  No EFI  boot detected."
        kname=$(lsblk -dno kname "$efi_mount")
        efi_disk=$(lsblk -dno pkname "/dev/$kname")

        if [[ $efi_disk ]]; then
            efi_partition=$(<"/sys/block/$efi_disk/$kname/partition")
        else
            # This is likely an md-raid or other type of virtual disk, we need
            # to dig a little deeper to find the actual physical disks and
            # partitions.
            kname=$(lsblk -dno kname "$efi_mount")
            cd "/sys/block/$kname/slaves" || exit_message \
"Unable to gather EFI data: Can't cd to /sys/block/$kname/slaves."
            if ! (shopt -s failglob; : ./*) 2>/dev/null; then
                exit_message \
"Unable to gather EFI data: No slaves found in /sys/block/$kname/slaves."
            fi
            efi_disk=()
            for d in *; do
                efi_disk+=("$(lsblk -dno pkname "/dev/$d")")
                efi_partition+=("$(<"$d/partition")")
                if [[ ! ${efi_disk[-1]} || ! ${efi_partition[-1]} ]]; then
                    exit_message \
"Unable to gather EFI data: Can't find disk name or partition number for $d."
                fi
            done
            cd -
        fi

        # We need to make sure that these packages are always installed in an
        # EFI system.
        always_install+=(
            "shim-${cpu_arch_suffix_map[$ARCH]}"
            "grub2-efi-${cpu_arch_suffix_map[$ARCH]}"
        )
    fi

    # Don't enable these module streams, even if they are enabled in the source
    # distro.
    declare -g -a module_excludes
    module_excludes=(
        libselinux-python:2.8
    )

    # Some OracleLinux modules have stream names of ol8 instead of rhel8 and ol
    # instead of rhel.  This is a map that does a glob match and replacement.
    local -A module_glob_map
    module_glob_map=(
        ['%:ol8']=:rhel8
        ['%:ol']=:rhel
    );

    # We need to map rockylinux repository names to the equivalent repositories
    # in the source distro.  To do that we look for known packages in each
    # repository and see what repo they came from.  We need to use repoquery for
    # this which requires downloading the package, so we pick relatively small
    # packages for this.
    declare -g -A repo_map pkg_repo_map
    declare -g -a managed_repos
    pkg_repo_map=(
        [baseos]=rootfiles.noarch
        [appstream]=apr-util-ldap.$ARCH
        [ha]=pacemaker-doc.noarch
        [powertools]=libaec-devel.$ARCH
        [extras]=epel-release.noarch
    )
#        [devel]=quota-devel.$ARCH

    PRETTY_NAME=$(os-release PRETTY_NAME)
    infomsg '%s' \
        "Preparing to migrate $PRETTY_NAME to Rocky Linux 8."$'\n\n' \
        "Determining repository names for $PRETTY_NAME"

    for r in "${!pkg_repo_map[@]}"; do
        printf '.'
        p=${pkg_repo_map[$r]}
        repoquery "$p" || continue
        repo_map[$r]=${repoquery_results[Repository]}
    done

    printf '%s\n' '' '' \
"Found the following repositories which map from $PRETTY_NAME to Rocky Linux 8:"
    column -t -s $'\t' -N "$PRETTY_NAME,Rocky Linux 8" < <(
        for r in "${!repo_map[@]}"; do
            printf '%s\t%s\n' "${repo_map[$r]}" "$r"
        done
    )

    infomsg $'\n'"Getting system package names for $PRETTY_NAME"

    # We don't know what the names of these packages are, we have to discover
    # them via various means. The most common means is to look for either a
    # distro-agnostic provides or a filename.  In a couple of cases we need to
    # jump through hoops to get a filename that is provided specifically by the
    # source distro.
    # Get info for each repository to determine which ones are subscription
    # managed.
    # system-release here is a bit of a hack, but it ensures that the
    # rocky-repos package will get installed.
    for r in "${!repo_map[@]}"; do
        repoinfo "${repo_map[$r]}"
        if [[ $r == "baseos" ]]; then
            local baseos_filename=system-release
            if [[ ! ${repoinfo_results[Repo-managed]} ]]; then
                baseos_filename="${repoinfo_results[Repo-filename]}"
            fi
            local baseos_gpgkey="${repoinfo_results[Repo-gpgkey]}"
        fi
        if [[ ${repoinfo_results[Repo-managed]} ]]; then
            managed_repos+=("${repo_map[$r]}")
        fi
    done

    # First get info for the baseos repo
    repoinfo "${repo_map[baseos]}"
    declare -g -A pkg_map provides_pkg_map
    declare -g -a addl_provide_removes addl_pkg_removes
    provides_pkg_map=(
        [rocky-backgrounds]=system-backgrounds
        [rocky-indexhtml]=redhat-indexhtml
        [rocky-repos]="$baseos_filename"
        [rocky-logos]=system-logos
        [rocky-logos-httpd]=system-logos-httpd
        [rocky-logos-ipa]=system-logos-ipa
        [rocky-gpg-keys]="$baseos_gpgkey"
        [rocky-release]=system-release
    )
    addl_provide_removes=(
        redhat-release
        redhat-release-eula
    )

    # Check to make sure that we don't already have a full or partial
    # RockyLinux install.
    if [[ $(rpm -qa "${!provides_pkg_map[@]}") ]]; then
        exit_message \
$'Found a full or partial RockyLinux install already in place.  Aborting\n'
$'because continuing with the migration could cause further damage to system.'
    fi

    for pkg in "${!provides_pkg_map[@]}"; do
        printf '.'
        prov=${provides_pkg_map[$pkg]}
        pkg_map[$pkg]=$(provides_pkg "$prov") ||
            exit_message "Can't get package that provides $prov."
    done
    for prov in "${addl_provide_removes[@]}"; do
        printf '.'
        local pkg;
        pkg=$(provides_pkg "$prov") || continue
        addl_pkg_removes+=("$pkg")
    done

# shellcheck disable=SC2140
    printf '%s\n' '' '' \
"Found the following system packages which map from $PRETTY_NAME to Rocky "\
"Linux 8:"
    column -t -s $'\t' -N "$PRETTY_NAME,Rocky Linux 8" < <(
        for p in "${!pkg_map[@]}"; do
            printf '%s\t%s\n' "${pkg_map[$p]}" "$p"
        done
    )

    infomsg $'\n'"Getting list of installed system packages."$'\n'

    readarray -t installed_packages < <(
        saferpm -qa --queryformat="%{NAME}\n" "${pkg_map[@]}"
    )
    declare -g -A installed_pkg_check installed_pkg_map
    for p in "${installed_packages[@]}"; do
        installed_pkg_check[$p]=1
    done
    for p in "${!pkg_map[@]}"; do
        if [[ ${pkg_map[$p]} && ${installed_pkg_check[${pkg_map[$p]}]} ]]; then
            installed_pkg_map[$p]=${pkg_map[$p]}
         fi
    done;

    # Special Handling for CentOS Stream Repos
    installed_sys_stream_repos_pkgs=()
    installed_stream_repos_pkgs=()
    for p in "${!stream_repos_pkgs[@]}"; do
        if [[ ${installed_pkg_map[$p]} &&
              ${installed_pkg_map[$p]} == "${stream_repos_pkgs[$p]}" ]]
        then
            # System package that needs to be swapped / disabled
            installed_pkg_map[$p]=
            installed_sys_stream_repos_pkgs+=( ${stream_repos_pkgs[$p]} )
        elif rpm --quiet -q "${stream_repos_pkgs[$p]}"; then
            # Non-system package, repos just need to be disabled.
            installed_stream_repos_pkgs+=( ${stream_repos_pkgs[$p]} )
        fi
    done

# shellcheck disable=SC2140
    printf '%s\n' '' \
"We will replace the following $PRETTY_NAME packages with their Rocky Linux 8 "\
"equivalents"
    column -t -s $'\t' -N "Packages to be Removed,Packages to be Installed" < <(
        for p in "${!installed_pkg_map[@]}"; do
            printf '%s\t%s\n' "${installed_pkg_map[$p]}" "$p"
        done
    )

    if (( ${#installed_sys_stream_repos_pkgs[@]} )); then
# shellcheck disable=SC2026
        printf '%s\n' '' \
'Also to aid the transition from CentOS Stream the following packages will be '\
'removed from the rpm database but the included repos will be renamed and '\
'retained but disabled:' \
            "${installed_sys_stream_repos_pkgs[@]}"
    fi

    if (( ${#installed_stream_repos_pkgs[@]} )); then
# shellcheck disable=SC2026
        printf '%s\n' '' \
'Also to aid the transition from CentOS Stream the repos included in the '\
'following packages will be renamed and retained but disabled:' \
            "${installed_stream_repos_pkgs[@]}"
    fi

    if (( ${#addl_pkg_removes[@]} )); then
        printf '%s\n' '' \
"In addition to the above the following system packages will be removed:" \
            "${addl_pkg_removes[@]}"
    fi

    # Release packages that are part of SIG's should be listed below when they
    # are available.
    # UPDATE: We may or may not do something with SIG's here, it could just be
    # left as a separate exercise to swap out the sig repos.
    #sigs_to_swap=()

    infomsg '%s' $'\n' \
        $'Getting a list of enabled modules for the system repositories.\n'

    # Get a list of system enabled modules.
    readarray -t enabled_modules < <(
        set -e -o pipefail
        safednf -y -q "${repo_map[@]/#/--repo=}" module list --enabled |
        awk '
            $1 == "@modulefailsafe", /^$/ {next}
            $1 == "Name", /^$/ {if ($1!="Name" && !/^$/) print $1":"$2}
            ' | sort -u
        set +e +o pipefail
    )

    # Map the known module name differences.
    disable_modules=()
    local i gl repl mod
    for i in "${!enabled_modules[@]}"; do
        mod=${enabled_modules[$i]}
        for gl in "${!module_glob_map[@]}"; do
            repl=${module_glob_map[$gl]}
            mod=${mod/$gl/$repl}
        done
        if [[ $mod != "${enabled_modules[$i]}" ]]; then
            disable_modules+=(${enabled_modules[$i]})
            enabled_modules[$i]=$mod
        fi
    done

    # Remove entries matching any excluded modules.
    if (( ${#module_excludes[@]} )); then
        printf '%s\n' '' "Excluding modules:" "${module_excludes[@]}"
        local -A module_check='()'
        local -a tmparr='()'
        for m in "${module_excludes[@]}"; do
            module_check[$m]=1
        done
        for m in "${enabled_modules[@]}"; do
            if [[ ! ${module_check[$m]} ]]; then
                tmparr+=("$m")
            fi
        done
        enabled_modules=("${tmparr[@]}")
    fi

    printf '%s\n' '' "Found the following modules to re-enable at completion:" \
        "${enabled_modules[@]}" ''

    if (( ${#managed_repos[@]} )); then
# shellcheck disable=SC2026
        printf '%s\n' '' \
'In addition, since this system uses subscription-manager the following '\
'managed repos will be disabled:' \
            "${managed_repos[@]}"
    fi
}

convert_info_dir=/root/convert
unset convert_to_rocky reinstall_all_rpms verify_all_rpms update_efi \
    container_macros

usage() {
  printf '%s\n' \
      "Usage: ${0##*/} [OPTIONS]" \
      '' \
      'Options:' \
      '-h Display this help' \
      '-r Convert to rocky' \
      '-V Verify switch' \
      '   !! USE WITH CAUTION !!'
  exit 1
} >&2

generate_rpm_info() {
    mkdir -p "$convert_info_dir"
    infomsg  "Creating a list of RPMs installed: $1"$'\n'
# shellcheck disable=SC2140
    rpm -qa --qf \
"%{NAME}|%{VERSION}|%{RELEASE}|%{INSTALLTIME}|%{VENDOR}|%{BUILDTIME}|"\
"%{BUILDHOST}|%{SOURCERPM}|%{LICENSE}|%{PACKAGER}\n" |
        sort > "${convert_info_dir}/$HOSTNAME-rpm-list-$1.log"
    infomsg "Verifying RPMs installed against RPM database: $1"$'\n\n'
    rpm -Va | sort -k3 > \
        "${convert_info_dir}/$HOSTNAME-rpm-list-verified-$1.log"
}

# Run a dnf update before the actual migration.
pre_update() {
    infomsg '%s\n' "Running dnf update before we attempt the migration."
    dnf -y update || exit_message \
$'Error running pre-update.  Stopping now to avoid putting the system in an\n'\
$'unstable state.  Please correct the issues shown here and try again.'
}

package_swaps() {
    # Save off any subscription-manager keys, just in case.
    if ( shopt -s failglob dotglob; : "$sm_ca_dir"/* ) 2>/dev/null ; then
        tmp_sm_ca_dir=$tmp_dir/sm-certs
        mkdir "$tmp_sm_ca_dir" ||
            exit_message "Could not create directory: $tmp_sm_ca_dir"
        cp -f -dR --preserve=all "$sm_ca_dir"/* "$tmp_sm_ca_dir/" ||
            exit_message "Could not copy certs to $tmp_sm_ca_dir"
    fi

    # prepare repo parameters
    local -a dnfparameters
    for repo in "${!repo_urls[@]}"; do
        dnfparameters+=( "--repofrompath=${repo},${repo_urls[${repo}]}" )
        dnfparameters+=( "--setopt=${repo}.gpgcheck=1" )
        dnfparameters+=( "--setopt=${repo}.gpgkey=file://${gpg_key_file}" )
    done

    # CentOS Stream specific processing
    if (( ${#installed_stream_repos_pkgs[@]} ||
          ${#installed_sys_stream_repos_pkgs[@]} )); then
        # Get a list of the repo files.
        local -a repos_files
        readarray -t repos_files < <(
            saferpm -ql "${installed_sys_stream_repos_pkgs[@]}" \
                "${installed_stream_repos_pkgs[@]}" |
            grep '^/etc/yum\.repos\.d/.\+\.repo$'
        )

        if (( ${#installed_sys_stream_repos_pkgs[@]} )); then
            # Remove the package from the rpm db.
            saferpm -e --justdb --nodeps -a \
                "${installed_sys_stream_repos_pkgs[@]}" ||
            exit_message \
"Could not remove packages from the rpm db: ${installed_sys_stream_repos_pkgs[*]}"
        fi

        # Rename the stream repos with a prefix and fix the baseurl.
        sed -i \
            -e 's/^\[/['"$stream_prefix"'/' \
            -e 's|^mirrorlist=|#mirrorlist=|' \
            -e 's|^#baseurl=http://mirror.centos.org/$contentdir/$stream/|baseurl=http://mirror.centos.org/centos/8-stream/|' \
            -e 's|^baseurl=http://vault.centos.org/$contentdir/$stream/|baseurl=https://vault.centos.org/centos/8-stream/|' \
            "${repos_files[@]}"
    fi

    # Use dnf shell to swap the system packages out.
    safednf -y shell --disablerepo=\* --noautoremove \
        --setopt=protected_packages= --setopt=keepcache=True \
        "${dnfparameters[@]}" \
        <<EOF
        remove ${installed_pkg_map[@]} ${addl_pkg_removes[@]}
        install ${!installed_pkg_map[@]}
        run
        exit
EOF

    # rocky-repos and rocky-gpg-keys are now installed, so we don't need the
    # key file anymore
    rm -rf "$gpg_tmp_dir"

    # We need to check to make sure that all of the original system packages
    # have been removed and all of the new ones have been added. If a package
    # was supposed to be removed and one with the same name added back then
    # we're kind of screwed for this check, as we can't be certain, but all the
    # packages we're adding start with "rocky-*" so this really shouldn't happen
    # and we can safely not check for it.  The worst that will happen is a rocky
    # linux package will be removed and then installed again.
    local -a check_removed check_installed
    readarray -t check_removed < <(
        saferpm -qa --qf '%{NAME}\n' "${installed_pkg_map[@]}" \
            "${addl_pkg_removes[@]}" | sort -u
    )

    if (( ${#check_removed[@]} )); then
        infomsg '%s' $'\n' \
            "Packages found on system that should still be removed.  Forcibly" \
            " removing them with rpm:"$'\n'
        # Removed packages still found on the system.  Forcibly remove them.
        for pkg in "${check_removed[@]}"; do
            # Extra safety measure, skip if empty string
            if [[ -z $pkg ]]; then
                continue
            fi
            printf '%s\n' "$pkg"
            saferpm -e --allmatches --nodeps "$pkg" ||
            saferpm -e --allmatches --nodeps --noscripts --notriggers "$pkg"
        done
    fi

    # Check to make sure we installed everything we were supposed to.
    readarray -t check_installed < <(
        {
            printf '%s\n' "${!installed_pkg_map[@]}" | sort -u
            saferpm -qa --qf '%{NAME}\n' "${!installed_pkg_map[@]}" | sort -u
        } | sort | uniq -u
    )
    if (( ${#check_installed[@]} )); then
        infomsg '%s' $'\n' \
            "Some required packages were not installed by dnf.  Attempting to" \
            " force with rpm:"$'\n'

        # Get a list of rpm packages to package names
        local -A rpm_map
        local -a file_list
        for rpm in /var/cache/dnf/{rockybaseos,rockyappstream}-*/packages/*.rpm
        do
            rpm_map[$(
                    rpm -q --qf '%{NAME}\n' --nodigest "$rpm" 2>/dev/null
                    )]=$rpm
        done

        # Attempt to install.
        for pkg in "${check_installed[@]}"; do
            printf '%s\n' "$pkg"
            if ! rpm -i --force --nodeps --nodigest "${rpm_map[$pkg]}" \
                2>/dev/null; then
                # Try to install the package in just the db, then clean it up.
                rpm -i --force --justdb --nodeps --nodigest "${rpm_map[$pkg]}" \
                    2>/dev/null

                # Get list of files that are still causing problems and donk
                # them.
                readarray -t file_list < <(
                    rpm -V "$pkg" 2>/dev/null | awk '$1!="missing" {print $2}'
                )
                for file in "${file_list[@]}"; do
                    rmdir "$file" ||
                    rm -f "$file" ||
                    rm -rf "$file"
                done

                # Now try re-installing the package to replace the missing
                # files.  Regardless of the outcome here we just accept it and
                # move on and hope for the best.
                rpm -i --reinstall --force --nodeps --nodigest \
                    "${rpm_map[$pkg]}" 2>/dev/null
            fi
        done
    fi

    # Distrosync
    infomsg $'Ensuring repos are enabled before the package swap\n'
    safednf -y --enableplugin=config_manager config-manager \
        --set-enabled "${!repo_map[@]}" || {
        printf '%s\n' 'Repo name missing?'
        exit 25
    }

    if (( ${#managed_repos[@]} )); then
        # Filter the managed repos for ones still in the system.
        readarray -t managed_repos < <(
            safednf -y -q repolist "${managed_repos[@]}" |
                    awk '$1!="repo" {print $1}'
        )

        if (( ${#managed_repos[@]} )); then
            infomsg $'\nDisabling subscription managed repos\n'
            safednf -y --enableplugin=config_manager config-manager \
                --disable "${managed_repos[@]}"
        fi
    fi

    if (( ${#disable_modules[@]} )); then
        infomsg $'Disabling modules\n\n'
        safednf -y module disable "${disable_modules[@]}" ||
            exit_message "Can't disable modules ${disable_modules[*]}"
    fi

    if (( ${#enabled_modules[@]} )); then
        infomsg $'Enabling modules\n\n'
        safednf -y module enable "${enabled_modules[@]}" ||
                exit_message "Can't enable modules ${enabled_modules[*]}"
    fi

    # Make sure that excluded modules are disabled.
    infomsg $'Disabling excluded modules\n\n'
    safednf -y module disable "${module_excludes[@]}" ||
            exit_message "Can't disable modules ${module_excludes[*]}"

    infomsg $'\nSyncing packages\n\n'
    dnf -y distro-sync || exit_message "Error during distro-sync."

    # Disable Stream repos.
    if (( ${#installed_sys_stream_repos_pkgs[@]} ||
          ${#installed_stream_repos_pkgs[@]} )); then
        dnf -y --enableplugin=config_manager config-manager --set-disabled \
            "$stream_prefix*" ||
            errmsg \
$'Failed to disable CentOS Stream repos, please check and disable manually.\n'

        if (( ${#stream_always_replace[@]} )) &&
            [[ $(saferpm -qa "${stream_always_replace[@]}") ]]; then
            safednf -y distro-sync "${stream_always_replace[@]}" ||
                exit_message "Error during distro-sync."
        fi

        infomsg $'\nCentOS Stream Migration Notes:\n\n'
        cat <<EOF
Because CentOS Stream leads RockyLinux by the next point release many packages
in Stream will have higher version numbers than those in RockyLinux, some will
even be rebased to a new upstream version.  Downgrading these packages to the
versions in RockyLinux carries the risk that the older version may not
recognize config files, data or other files generated by the newer version in
Stream.

To avoid issues with this the newer package versions from CentOS Stream have
been retained.  Also the CentOS Stream repositories have been retained but
renamed with a prefix of "stream-" to avoid clashing with RockyLinux
repositories, but these same repos have also been disabled so that future
package installs will come from the stock RockyLinux repositories.

If you do nothing except update to the next point release of RockyLinux when it
becomes available then the packages retained from Stream should be replaced at
that time.  If you need to update a package from Stream (eg: to fix a bug or
security issue) then you will need to enable the appropriate repository to do
so.
EOF
    fi

    if rpm --quiet -q subscription-manager; then
        infomsg $'Subscription Manager found on system.\n\n'
        cat <<EOF
If you're converting from a subscription-managed distribution such as RHEL then
you may no longer need subscription-manager or dnf-plugin-subscription-manager.
While it won't hurt anything to have it on your system you may be able to safely
remove it with:

"dnf remove subscription-manager dnf-plugin-subscription-manager".

Take care that it doesn't remove something that you want to keep.

The subscription-manager dnf plugin may be enabled for the benefit of
Subscription Management. If no longer desired, you can use
"subscription-manager config --rhsm.auto_enable_yum_plugins=0" to block this
behavior.
EOF
    fi

    if (( ${#always_install[@]} )); then
        safednf -y install "${always_install[@]}" || exit_message \
            "Error installing required packages: ${always_install[*]}"
    fi

    if [[ $tmp_sm_ca_dir ]]; then
        # Check to see if there's Subscription Manager certs which have been
        # removed
        local -a removed_certs
        readarray -t removed_certs < <((
            shopt -s nullglob dotglob
            local -a certs
            cd "$sm_ca_dir" && certs=(*)
            cd "$tmp_sm_ca_dir" && certs+=(*)
            IFS=$'\n'
            printf '%s' "${certs[*]}"
        ) | sort | uniq -u)

        if (( ${#removed_certs[@]} )); then
            cp -n -dR --preserve=all "$tmp_sm_ca_dir"/* "$sm_ca_dir/" ||
                exit_message "Could not copy certs back to $sm_ca_dir"
            
            infomsg '%s' \
                $'Some Subscription Manager certificates ' \
                "were restored to $sm_ca_dir after"$'\n' \
                $'migration so that the subscription-manager ' \
                $'command will continue to work:\n\n'
            printf '%s\n' "${removed_certs[@]}" ''
            cat <<EOF
If you no longer need to use the subscription-manager command then you may
safely remove these files.
EOF
        fi
    fi
}

# Check if this system is running on EFI
# If yes, we'll need to run fix_efi() at the end of the conversion
efi_check () {
    # Check if we have /sys mounted and it is looking sane
    if ! [[ -d /sys/class/block ]]; then
        exit_message "/sys is not accessible."
    fi
    
    # Now that we know /sys is reliable, use it to check if we are running on
    # EFI or not
    if systemd-detect-virt --quiet --container; then
        declare -g container_macros
        container_macros=$(mktemp /etc/rpm/macros.zXXXXXX)
        printf '%s\n' '%_netsharedpath /sys:/proc' > "$container_macros"
    elif [[ -d /sys/firmware/efi/ ]]; then
        declare -g update_efi
        update_efi=true
    fi
}

# Called to update the EFI boot.
fix_efi () (
    grub2-mkconfig -o /boot/efi/EFI/rocky/grub.cfg ||
            exit_message "Error updating the grub config."
    for i in "${!efi_disk[@]}"; do
        efibootmgr -c -d "/dev/${efi_disk[$i]}" -p "${efi_partition[$i]}" \
            -L "Rocky Linux" -l "/EFI/rocky/shim${cpu_arch_suffix_map[$ARCH]}.efi" ||
            exit_message "Error updating uEFI firmware."
    done
)

# Download and verify the Rocky Linux package signing key
establish_gpg_trust () {
    # create temp dir and verify it is really created and empty, so we are sure
    # deleting it afterwards won't cause any harm
    declare -g gpg_tmp_dir
    gpg_tmp_dir=$tmp_dir/gpg
    if ! mkdir "$gpg_tmp_dir" || [[ ! -d "$gpg_tmp_dir" ]]; then
        exit_message "Error creating temp dir"
    fi
    # failglob makes pathname expansion fail if empty, dotglob adds files
    # starting with . to pathname expansion
    if ( shopt -s failglob dotglob; : "$gpg_tmp_dir"/* ) 2>/dev/null ; then
        exit_message "Temp dir not empty"
    fi

    # extract the filename from the url, use the temp dir just created
    declare -g gpg_key_file="$gpg_tmp_dir/${gpg_key_url##*/}"

    if ! curl -L -o "$gpg_key_file" --silent --show-error "$gpg_key_url"; then
        rm -rf "$gpg_tmp_dir"
        exit_message "Error downloading the Rocky Linux signing key."
    fi

    if ! sha512sum --quiet -c <<<"$gpg_key_sha512 $gpg_key_file"; then
        rm -rf "$gpg_tmp_dir"
        exit_message "Error validating the signing key."
    fi
}

## End actual work

noopts=0
while getopts "hrVR" option; do
  (( noopts++ ))
  case "$option" in
    h)
      usage
      ;;
    r)
      convert_to_rocky=true
      ;;
    V)
      verify_all_rpms=true
      ;;
    *)
      errmsg $'Invalid switch\n'
      usage
      ;;
  esac
done
if (( ! noopts )); then
    usage
fi

pre_setup
trap exit_clean EXIT
pre_check
efi_check
bin_check

if [[ $verify_all_rpms ]]; then
  generate_rpm_info begin
fi

if [[ $convert_to_rocky ]]; then
    collect_system_info
    establish_gpg_trust
    pre_update
    package_swaps
fi

if [[ $verify_all_rpms && $convert_to_rocky ]]; then
  generate_rpm_info finish
  infomsg $'You may review the following files:\n'
  printf '%s\n' "$convert_info_dir/$HOSTNAME-rpm-list-"*.log
fi

if [[ $update_efi && $convert_to_rocky ]]; then
    fix_efi
fi

printf '\n\n\n'
if [[ $convert_to_rocky ]]; then
    infomsg $'\nDone, please reboot your system.\n'
fi
logmessage