概述

自 2006 年 Oracle Linux 推出以来，Oracle Linux 一直完全免费下载和使用，无需任何许可费用。Oracle 为完整的操作环境提供支持，该环境提供集成的虚拟化、管理和云原生计算工具套件，以及 Linx 操作系统。我们知道自从CENTOS断更之后，Oracle Linux，是一个可选项，那么对于目前存量系统，如何从CENTOS一键迁移到Oracle Linux呢？今天分享一键迁移脚本，让你轻松过渡至Oracle Linux

一键迁移脚本

#!/bin/bash# Copyright (c) 2020, 2021 Oracle and/or its affiliates.# Licensed under the Universal Permissive License v 1.0 as shown at  Script to switch CentOS (or other similar distribution) to the# Oracle Linux yum repository.#set -eunset CDPATHyum_url=(uname -m)bad_packages=(centos-backgrounds centos-gpg-keys centos-logos centos-release centos-release-cr desktop-backgrounds-basic \              centos-release-advanced-virtualization centos-release-ansible26 centos-release-ansible-27 \              centos-release-ansible-28 centos-release-ansible-29 centos-release-azure \              centos-release-ceph-jewel centos-release-ceph-luminous centos-release-ceph-nautilus \              centos-release-ceph-octopus centos-release-configmanagement centos-release-dotnet centos-release-fdio \              centos-release-gluster40 centos-release-gluster41 centos-release-gluster5 \              centos-release-gluster6 centos-release-gluster7 centos-release-gluster8 \              centos-release-gluster-legacy centos-release-messaging centos-release-nfs-ganesha28 \              centos-release-nfs-ganesha30 centos-release-nfv-common \              centos-release-nfv-openvswitch centos-release-openshift-origin centos-release-openstack-queens \              centos-release-openstack-rocky centos-release-openstack-stein centos-release-openstack-train \              centos-release-openstack-ussuri centos-release-opstools centos-release-ovirt42 centos-release-ovirt43 \              centos-release-ovirt44 centos-release-paas-common centos-release-qemu-ev centos-release-qpid-proton \              centos-release-rabbitmq-38 centos-release-samba411 centos-release-samba412 \              centos-release-scl centos-release-scl-rh centos-release-storage-common \              centos-release-virt-common centos-release-xen centos-release-xen-410 \              centos-release-xen-412 centos-release-xen-46 centos-release-xen-48 centos-release-xen-common \              libreport-centos libreport-plugin-mantisbt libreport-plugin-rhtsupport python3-syspurpose \              python-oauth rocky-backgrounds rocky-gpg-keys rocky-logos rocky-release sl-logos yum-rhn-plugin)usage() {    echo "Usage: ${0##*/} [OPTIONS]"    echo    echo "OPTIONS"    echo "-h"    echo "        Display this help and exit"    echo "-k"    echo "        Do not install the UEK kernel and disable UEK repos"    echo "-r"    echo "        Reinstall all CentOS RPMs with Oracle Linux RPMs"    echo "        Note: This is not necessary for support"    echo "-V"    echo "        Verify RPM information before and after the switch"    exit 1} >&2have_program() {    hash "$1" >/dev/null 2>&1}dep_check() {    if ! have_program "$1"; then        exit_message "'${1}' command not found. Please install or add it to your PATH and try again."    fi}exit_message() {    echo "$1"    echo "For assistance, please open an issue via GitHub: ${github_url}."    exit 1} >&2final_failure() {    echo "An error occurred while attempting to switch this system to Oracle Linux and it may be in an unstable/unbootable state. To avoid further issues, the script has terminated."}generate_rpms_info() {    echo "Creating a list of RPMs installed $1 the switch"    rpm -qa --qf "%{NAME}-%{EPOCH}:%{VERSION}-%{RELEASE}.%{ARCH}|%{INSTALLTIME}|%{VENDOR}|%{BUILDTIME}|%{BUILDHOST}|%{SOURCERPM}|%{LICENSE}|%{PACKAGER}\n" | sed 's/(none)://g' | sort > "/var/tmp/$(hostname)-rpms-list-$1.log"    echo "Verifying RPMs installed $1 the switch against RPM database"    rpm -Va | sort -k3 > "/var/tmp/$(hostname)-rpms-verified-$1.log"}## Start of scriptreinstall_all_rpms=falseverify_all_rpms=falseinstall_uek_kernel=truewhile getopts "hrkV" option; do    case "$option" in        h) usage ;;        r) reinstall_all_rpms=true ;;        k) install_uek_kernel=false ;;        V) verify_all_rpms=true ;;        *) usage ;;    esacdone# Force the UEK on Arm hostsif [ "$arch" == "aarch64" ]; then    install_uek_kernel=truefiif [ "$(id -u)" -ne 0 ]; then    exit_message "You must run this script as root.Try running 'su -c ${0}'."fiecho "Checking for required packages..."for pkg in rpm yum curl; do    dep_check "${pkg}"doneecho "Checking your distribution..."if ! old_release=$(rpm -q --whatprovides /etc/redhat-release); then    exit_message "You appear to be running an unsupported distribution."fiif [ "$(echo "${old_release}" | wc -l)" -ne 1 ]; then    exit_message "Could not determine your distribution because multiplepackages are providing redhat-release:$old_release"fi# Collect information about RPMs before the switchif "${verify_all_rpms}"; then    generate_rpms_info beforeficase "${old_release}" in    redhat-release*) ;;    centos-release* | centos-linux-release*) ;;    rocky-release*) ;;    sl-release*) ;;    oraclelinux-release*|enterprise-release*)        exit_message "You appear to be already running Oracle Linux."        ;;    *) exit_message "You appear to be running an unsupported distribution." ;;esacos_version=$(rpm -q "${old_release}" --qf "%{version}")major_os_version=${os_version:0:1}if "${install_uek_kernel}"; then  base_packages=(basesystem initscripts oracle-logos kernel-uek)else  base_packages=(basesystem initscripts oracle-logos)ficase "$os_version" in    8*)        repo_file=public-yum-ol8.repo        new_releases=(oraclelinux-release oraclelinux-release-el8 redhat-release)        base_packages=("${base_packages[@]}" plymouth grub2 grubby)        ;;    7*)        repo_file=public-yum-ol7.repo        new_releases=(oraclelinux-release oraclelinux-release-el7 redhat-release-server)        base_packages=("${base_packages[@]}" plymouth grub2 grubby)        ;;    6*)        repo_file=public-yum-ol6.repo        new_releases=(oraclelinux-release oraclelinux-release-el6 redhat-release-server)        base_packages=("${base_packages[@]}" oraclelinux-release-notes plymouth grub grubby)        ;;    *) exit_message "You appear to be running an unsupported distribution." ;;esac# Some packages need to be replaced as part of switch# Store as key value, if the first RPM is found then it's removed and the associated RPM installeddeclare -A packages_to_replace=(    [epel-release]="oracle-epel-release-el${major_os_version}")# Switch RPMs if they're installedfor package_name in "${!packages_to_replace[@]}"; do    if rpm -q "${package_name}" ; then        bad_packages+=("${package_name}")        base_packages+=("${packages_to_replace[${package_name}]}")    fidoneecho "Checking for yum lock..."if [ -f /var/run/yum.pid ]; then    yum_lock_pid=$(cat /var/run/yum.pid)    yum_lock_comm=$(cat "/proc/${yum_lock_pid}/comm")    exit_message "Another app is currently holding the yum lock.The other application is: $yum_lock_commRunning as pid: $yum_lock_pidRun 'kill $yum_lock_pid' to stop it, then run this script again."fiecho "Checking for required python packages..."case "$os_version" in    8*)        dep_check /usr/libexec/platform-python        ;;    *)        dep_check python2        ;;esacif [[ "$os_version" =~ 8.* ]]; then    echo "Identifying dnf modules that are enabled"    # There are a few dnf modules that are named after the distribution    #  for each steam named 'rhel' or 'rhel8' we need to make alterations to 'ol' or 'ol8'    #  Before we start the switch, identify if there are any present we don't know how to handle    mapfile -t modules_enabled < <(dnf module list --enabled | grep rhel | awk '{print $1}')    if [[ "${modules_enabled[*]}" ]]; then        # Create an array of modules we don't know how to manage        unknown_modules=()        for module in "${modules_enabled[@]}"; do            case ${module} in                container-tools|go-toolset|jmc|llvm-toolset|rust-toolset|virt)                    ;;                *)                    # Add this module name to our array of modules we don't know how to manage                    unknown_modules+=("${module}")                    ;;            esac        done        # If we have any modules we don't know how to manage, ask the user how to proceed        if [ ${#unknown_modules[@]} -gt 0 ]; then            echo "This tool is unable to automatically switch module(s) '${unknown_modules[*]}' from a CentOS 'rhel' stream toan Oracle Linux equivalent. Do you want to continue and resolve it manually?You may want select No to stop and raise an issue on ${github_url} for advice."            select yn in "Yes" "No"; do                case $yn in                    Yes )                        break                        ;;                    No )                        echo "Unsure how to switch module(s) '${unknown_modules[*]}'. Exiting as requested"                        exit 1                        ;;                esac            done        fi    fifiecho "Finding your repository directory..."case "$os_version" in    8*)reposdir=$(/usr/libexec/platform-python -c "import dnfimport osdir = dnf.Base().conf.get_reposdirif os.path.isdir(dir):    print(dir)")        ;;    *)        reposdir=$(python2 -c "import yumimport osfor dir in yum.YumBase().doConfigSetup(init_plugins=False).reposdir:    if os.path.isdir(dir):        print dir        break")        ;;esacecho "Learning which repositories are enabled..."case "$os_version" in    8*)        enabled_repos=$(/usr/libexec/platform-python -c "import dnfbase = dnf.Base()base.read_all_repos()for repo in base.repos.iter_enabled():  print(repo.id)")        ;;    *)        enabled_repos=$(python2 -c "import yumbase = yum.YumBase()base.doConfigSetup(init_plugins=False)for repo in base.repos.listEnabled():  print repo")        ;;esacecho -e "Repositories enabled before update include:\n${enabled_repos}"if [ -z "${reposdir}" ]; then    exit_message "Could not locate your repository directory."ficd "$reposdir"# No  file exists# Download the content for 6 and 7 based systems and directly enter the content for 8 based systemscase "$os_version" in    8*)        cat > "switch-to-oraclelinux.repo" <<-'EOF'		[ol8_baseos_latest]		name=Oracle Linux 8 BaseOS Latest ($basearch)		baseurl=		gpgkey=		gpgcheck=1		enabled=1		[ol8_appstream]		name=Oracle Linux 8 Application Stream ($basearch)		baseurl=		gpgkey=		gpgcheck=1		enabled=1EOF        if [ "$arch" == "x86_64" ]; then            cat >> "switch-to-oraclelinux.repo" <<-'EOF'    		[ol8_UEKR6]		name=Latest Unbreakable Enterprise Kernel Release 6 for Oracle Linux $releasever ($basearch)		baseurl=		gpgkey=		gpgcheck=1		enabled=1EOF        fi        ;;    *)        echo "Downloading Oracle Linux yum repository file..."        if ! curl -o "switch-to-oraclelinux.repo" "${yum_url}/${repo_file}"; then            exit_message "Could not download $repo_file from $yum_url.        Are you behind a proxy? If so, make sure the 'http_proxy' environment        variable is set with your proxy address."        fi        ;;esacecho "Looking for yumdownloader..."if ! have_program yumdownloader; then    # CentOS 6 mirrors are now offline, if yumdownloader tool is not present then    #  use OL6 as source for yum-utils and disable all other repos.    # Use the existing distributions copy for other platforms    case "$os_version" in        6*)            curl -o /etc/pki/rpm-gpg/RPM-GPG-KEY-oracle             yum -y install yum-utils --disablerepo \* --enablerepo ol6_latest || true            ;;        *)            yum -y install yum-utils --disablerepo ol\* || true            ;;    esac    dep_check yumdownloaderficd "$(mktemp -d)"trap final_failure ERR# Most distros keep their /etc/yum.repos.d content in the -release rpm. CentOS 8 does not and the behaviour changes between#  minor releases; 8.0 uses 'centos-repos' while 8.3 uses 'centos-linux-repos', glob for simplicity.if [[ $old_release =~ ^centos-release-8.* ]] || [[ $old_release =~ ^centos-linux-release-8.* ]]; then    old_release=$(rpm -qa centos*repos)fi# Most distros keep their /etc/yum.repos.d content in the -release rpm. Rocky Linux 8 does not.if [[ $old_release =~ ^rocky-release-8.* ]]; then    old_release=$(rpm -qa rocky*repos)fiecho "Backing up and removing old repository files..."# Identify repo files from the base OSrpm -ql "$old_release" | grep '\.repo$' > repo_files# Identify repo files from 'CentOS extras'if [ "$(rpm -qa "centos-release-*" | wc -l)" -gt 0 ] ; then    rpm -qla "centos-release-*" | grep '\.repo$' >> repo_filesfiwhile read -r repo; do    if [ -f "$repo" ]; then        cat - "$repo" > "$repo".disabled <<EOF# This is a yum repository file that was disabled by# ${0##*/}, a script to convert CentOS to Oracle Linux.# Please see $yum_url for more information.EOF        tmpfile=$(mktemp repo.XXXXX)        echo "$repo" | cat - "$repo" > "$tmpfile"        rm "$repo"    fidone < repo_files# Disable the explicit distroverpkg as centos-release provides the correct value# for system-release(releasever).# See  "Removing CentOS-specific yum configuration from /etc/yum.conf"sed -i.bak -e 's/^distroverpkg/#&/g' -e 's/^bugtracker_url/#&/g' /etc/yum.confecho "Downloading Oracle Linux release package..."if ! yumdownloader "${new_releases[@]}"; then    {        echo "Could not download the following packages from $yum_url:"        echo "${new_releases[@]}"        echo        echo "Are you behind a proxy? If so, make sure the 'http_proxy' environment"        echo "variable is set with your proxy address."    } >&2    final_failurefiecho "Switching old release package with Oracle Linux..."rpm -i --force "${new_releases[@]/%/*.rpm}"rpm -e --nodeps "$old_release"rm -f "${reposdir}/switch-to-oraclelinux.repo"# Disable UEK repos if UEK kernel is not being installedif ! "${install_uek_kernel}"; then  echo "Disabling UEK repositories since we are not installing the UEK kernel"  yum-config-manager --disable \*UEK*fi# At this point, the switch is completed.trap - ERR# When an additional enabled CentOS repository has a match with Oracle Linux#  then automatically enable the OL repository to ensure the RPM is maintained## Create an associate array where the key is the CentOS reponame and the value#  contains the method of getting the content (Enable a repo or install an RPM)#  and the details of the repo or RPMcase "$os_version" in    6*)        declare -A repositories=(            [base-debuginfo]="REPO ;            [updates]="REPO ol6_latest"        )        ;;    7*)        declare -A repositories=(            [base-debuginfo]="REPO ;            [updates]="REPO ol7_latest,ol7_optional_latest"            [centos-ceph-jewel]="RPM oracle-ceph-release-el7"            [centos-gluster41]="RPM oracle-gluster-release-el7"            [centos-gluster5]="RPM oracle-gluster-release-el7"            [centos-gluster46]="RPM oracle-gluster-release-el7"            [centos-nfs-ganesha30]="RPM oracle-gluster-release-el7"            [centos-ovirt42]="RPM oracle-ovirt-release-el7"            [centos-ovirt43]="RPM oracle-ovirt-release-el7"            [centos-sclo-sclo]="RPM oracle-softwarecollection-release-el7"            [centos-sclo-rh]="RPM oracle-softwarecollection-release-el7"        )        ;;    8*)        declare -A repositories=(            [AppStream]="REPO ol8_appstream"            [appstream]="REPO ol8_appstream"            [BaseOS]="REPO ol8_baseos_latest"            [baseos]="REPO ol8_baseos_latest"            [HighAvailability]="REPO ol8_addons"            [ha]="REPO ol8_addons"            [PowerTools]="REPO ol8_codeready_builder"            [powertools]="REPO ol8_codeready_builder"            [centos-release-nfs-ganesha28]="RPM oracle-gluster-release-el8"            [centos-gluster6-test]="RPM oracle-gluster-release-el8"            [centos-gluster7]="RPM oracle-gluster-release-el8"            [centos-gluster8]="RPM oracle-gluster-release-el8"        )        ;;esac# For each entry in the list, enable itfor reponame in ${enabled_repos}; do    # action[0] will be REPO or RPM    # action[1] will be the repos details or the RPMs name    IFS=" " read -r -a action <<< "${repositories[${reponame}]}"    if [[ -n ${action[0]} ]]; then        if [ "${action[0]}" == "REPO" ] ; then            matching_repo=${action[1]}            echo "Enabling ${matching_repo} which replaces ${reponame}"            # An RPM that describes debuginfo repository does not exist            #  check to see if the repo id starts with https, if it does then            #  create a new repo pointing to the repository            if [[ ${matching_repo} =~ https.* ]]; then                yum-config-manager --add-repo "${matching_repo}"            else                yum-config-manager --enable "${matching_repo}"            fi        elif [ "${action[0]}" == "RPM" ] ; then            matching_rpm=${action[1]}            echo "Installing ${matching_rpm} to get content that replaces ${reponame}"            yum --assumeyes --disablerepo "*" --enablerepo "ol*_latest" install "${matching_rpm}"        fi    fidoneecho "Installing base packages for Oracle Linux..."if ! yum shell -y <<EOFremove ${bad_packages[@]}install ${base_packages[@]}runEOFthen    exit_message "Could not install base packages.Run 'yum distro-sync' to manually install them."fiif [ -x /usr/libexec/plymouth/plymouth-update-initrd ]; then    echo "Updating initrd..."    /usr/libexec/plymouth/plymouth-update-initrdfiecho "Switch successful. Syncing with Oracle Linux repositories."if ! yum -y distro-sync; then    exit_message "Could not automatically sync with Oracle Linux repositories.Check the output of 'yum distro-sync' to manually resolve the issue."fi# CentOS specific replacementscase "$os_version" in    7*)        # Prior to switch this is a dependancy of the yum rpm, now we've switched we can remove it        if rpm -q yum-plugin-fastestmirror; then            yum erase -y yum-plugin-fastestmirror        fi        ;;    8*)        # There are a few dnf modules that are named after the distribution        #  for each steam named 'rhel' or 'rhel8' perform a module reset and enable        if [[ "${modules_enabled[*]}" ]]; then            for module in "${modules_enabled[@]}"; do                dnf module reset -y "${module}"                case ${module} in                container-tools|go-toolset|jmc|llvm-toolset|rust-toolset)                    dnf module enable -y "${module}":ol8                    ;;                virt)                    dnf module enable -y "${module}":ol                    ;;                *)                    echo "Unsure how to transform module ${module}"                    ;;                esac            done            dnf --assumeyes --disablerepo "*" --enablerepo "ol8_appstream" update        fi        # Two logo RPMs aren't currently covered by 'replaces' metadata, replace by hand.        if rpm -q centos-logos-ipa; then            dnf swap -y centos-logos-ipa oracle-logos-ipa        fi        if rpm -q centos-logos-httpd; then            dnf swap -y centos-logos-httpd oracle-logos-httpd        fi        ;;esacif "${reinstall_all_rpms}"; then    echo "Testing for remaining CentOS RPMs"    # If CentOS and Oracle Linux have identically versioned RPMs then those RPMs are left unchanged.    #  This should have no technical impact but for completeness, reinstall these RPMs    #  so there is no accidental cross pollination.    case "$arch" in        x86_64)            mapfile -t list_of_centos_rpms < <(rpm -qa --qf "%{NAME}-%{VERSION}-%{RELEASE} %{VENDOR}\n" | grep CentOS |  awk '{print $1}')            ;;        aarch64)            mapfile -t list_of_centos_rpms < <(rpm -qa --qf "%{NAME}-%{VERSION}-%{RELEASE} %{VENDOR}\n" | grep CentOS | grep -v kernel | awk '{print $1}')            ;;    esac    if [[ -n "${list_of_centos_rpms[*]}" ]] && [[ "${list_of_centos_rpms[*]}" -ne 0 ]]; then        echo "Reinstalling RPMs: ${list_of_centos_rpms[*]}"        yum --assumeyes --disablerepo "*" --enablerepo "ol*" reinstall "${list_of_centos_rpms[@]}"    fi    # See if non-Oracle RPMs are present and print them    mapfile -t non_oracle_rpms < <(rpm -qa --qf "%{NAME}-%{VERSION}-%{RELEASE}|%{VENDOR}|%{PACKAGER}\n" |grep -v Oracle)    if [[ -n "${non_oracle_rpms[*]}" ]]; then        echo "The following non-Oracle RPMs are installed on the system:"        printf '\t%s\n' "${non_oracle_rpms[@]}"        echo "This may be expected of your environment and does not necessarily indicate a problem."        echo "If a large number of CentOS RPMs are included and you're unsure why please open an issue on ${github_url}"    fifiecho "Sync successful."if [ "$arch" == "aarch64" ]; then    echo "Host is running an Arm CPU: removing RHCK."    echo "Important: you MUST reboot this instance as soon as possible."    dnf config-manager --setopt=protect_running_kernel=0 --save    dnf -y remove kernel kernel-core kernel-modules    dnf config-manager --setopt=protect_running_kernel=1 --saveficase "$os_version" in    7* | 8*)        echo "Updating the GRUB2 bootloader."        if [ -d /sys/firmware/efi ]; then            grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg        else            grub2-mkconfig -o /boot/grub2/grub.cfg        fi    ;;esacif "${install_uek_kernel}"; then    echo "Switching default boot kernel to the UEK."    uek_path=$(find /boot -name "vmlinuz-*.el${os_version}uek.${arch}")    grubby --set-default="${uek_path}"fiecho "Removing yum cache"rm -rf /var/cache/{yum,dnf}# Collect information about RPMs after the switchif "${verify_all_rpms}"; then    generate_rpms_info after    echo "Review the output of following files:"    find /var/tmp/ -type f -name "$(hostname)-rpms-*.log"fiecho "Switch complete."case "$arch" in    "x86_64")        echo "Oracle recommends rebooting this system."    ;;    "aarch64")        echo "This instance must be rebooted as soon as possible."    ;;esac

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