LTS

    Innovation Version

      Common Skills

      Configuring the Network

      1. Configure the IP address.

        Run the ip command to configure an address for the interface. interface-name indicates the name of the NIC.

        ip addr [ add | del ] address dev interface-name
        
      2. Configure a static IP address.

        $ Configure the static IP address.
        ip address add 192.168.0.10/24 dev enp3s0
        
        # Run the following command as the root user to query the configuration result:
        ip addr show dev enp3s0
        
        # The result is as follows:
        2: enp3s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
        link/ether 52:54:00:aa:ad:4a brd ff:ff:ff:ff:ff:ff
        inet 192.168.202.248/16 brd 192.168.255.255 scope global dynamic noprefixroute enp3s0
        valid_lft 9547sec preferred_lft 9547sec
        inet 192.168.0.10/24 scope global enp3s0
        valid_lft forever preferred_lft forever
        inet6 fe80::32e8:cc22:9db2:f4d4/64 scope link noprefixroute
        valid_lft forever preferred_lft forever
        
      3. Configure a static route.

        Run the ip route add command to add a static route to the routing table and run the ip route del command to delete a static route. The common format of the ip route command is as follows:

        ip route [ add | del | change | append | replace ] destination-address
        
        • To add a static route to the host address, run the following command as the root user:
        ip route add 192.168.2.1 via 10.0.0.1 [dev interface-name]
        
        • To add a static route to the network, run the following command as the root user:
        ip route add 192.168.2.0/24 via 10.0.0.1 [dev interface-name]
        
      4. Configure the network using the ifcfg file.

        Modify the ifcfg-enp4s0 file generated in the /etc/sysconfig/network-scripts/ directory as the root user. The following is an example:

        TYPE=Ethernet
        PROXY_METHOD=none
        BROWSER_ONLY=no
        BOOTPROTO=none
        IPADDR=192.168.0.10
        PREFIX=24
        DEFROUTE=yes
        IPV4_FAILURE_FATAL=no
        IPV6INIT=yes
        IPV6_AUTOCONF=yes
        IPV6_DEFROUTE=yes
        IPV6_FAILURE_FATAL=no
        IPV6_ADDR_GEN_MODE=stable-privacy
        NAME=enp4s0static
        UUID=xx
        DEVICE=enp4s0
        ONBOOT=yes
        

      Managing RPM Packages

      The full name of RPM is RPM Package Manager, which is intended to manage Red Hat software packages. It is used in mainstream distributions such as openEuler, Fedora, Red Hat, Mandriva, SUSE and YellowDog, and distributions developed based on these distributions.

      RPM installs the required software to a set of management programs on the Linux host in database record mode. The software to be installed is compiled and packaged, and the default database record in the packaged software records the dependencies required for the software installation. When a user installs the software on a Linux host, RPM checks whether the dependencies on the Linux host meets the requirements based on the data recorded in it.

      • If yes, install the software.
      • If no, do not install the software.

      During the installation, all software information is written into the RPM database for subsequent query, verification, and uninstallation.

      en-us_other_0000001337581224

      1. Default installation path of the RPM packages

        Generally, RPM uses the default installation path. (The default installation path can be queried by running a command and will be described in detail in subsequent sections.) All installation files are distributed to the directories listed in the following table by type.

        RPM installation paths and their meanings

        Installation PathDescription
        /etc/Configuration file installation directory
        /usr/bin/Installation directory of the executable commands
        /usr/lib/Path for storing the function library used by the program
        /usr/share/docLocation where the basic software user manual is saved
        /usr/share/man/Path for saving the help file

        Note: You can manually specify the installation path of RPM, but this method is not recommended. After the installation path is manually specified, all installation files are installed in the specified path, and the command for querying the installation path in the system cannot be used. The command can be identified by the system only after being manually configured.

      2. rpm command options

        Checking the RPM Signature of the Software Package

        Before installing the RPM package on a Linux host, check the PGP signature. After ensuring that the signature integrity and source are correct, run the rpm --checksig command to verify the validity:

        rpm --checksig nano-2.3.1-10.el7.x86_64.rpm
        

        Installing RPM Packages

        To install RPM packages in Linux, use the -i option in the rpm command.

        rpm -ivh nano-2.3.1-10.el7.x86_64.rpm
        
        • -i: installs the software package.
        • -v: displays detailed information.
        • -h: lists flags during suite installation.

        Querying an Installed RPM Package

        To query an RPM package (dnf) installed in the Linux system, use the -q option in the rpm command.

        rpm -q dnf
        
        • -q: query operation

        If the specified package is not installed, the following error message is displayed:

        package dnf is not installed
        

        Querying All Installed RPM Packages

        To query all RPM packages installed in Linux, use the -qa option in the rpm command.

        $ rpm -qa 
        dracut-config-rescue-055-7.oe2203sp2.x86_64
        parted-3.5-1.oe2203sp2.x86_64
        irqbalance-1.8.0-9.oe2203sp2.x86_64
        ......
        

        Note: When using the -qa option, use the pipe character (|) together to improve the search accuracy.

        Querying Details About an Installed RPM Package

        Use the -qi option in the rpm command to query the details of an RPM package installed in the system.

        $ rpm -qi python3
        Name        : python3
        Version     : 3.9.9
        Release     : 24.oe2203sp2
        Architecture: x86_64
        Install Date: Wed 05 Jul 2023 08:30:23 PM CST
        Group       : Unspecified
        Size        : 35916839
        License     : Python-2.0
        Signature   : RSA/SHA1, Wed 28 Jun 2023 01:11:59 PM CST, Key ID d557065eb25e7f66
        Source RPM  : python3-3.9.9-24.oe2203sp2.x86_64.rpm
        Build Date  : Wed 28 Jun 2023 01:11:59 PM CST
        Build Host  : obs-worker1639015616-x86-0001
        Packager    : http://openeuler.org
        Vendor      : http://openeuler.org
        URL         : https://www.python.org/
        Summary     : Interpreter of the Python3 programming language
        Description :
        Python combines remarkable power with very clear syntax. It has modules,
        classes, exceptions, very high level dynamic data types, and dynamic
        typing. There are interfaces to many system calls and libraries, as well
        as to various windowing systems. New built-in modules are easily written
        in C or C++ (or other languages, depending on the chosen implementation).
        Python is also usable as an extension language for applications written
        in other languages that need easy-to-use scripting or automation interfaces.
        
        This package Provides python version 3.
        

        Querying All Files in an RPM Package

        To query the file list of an RPM package that is not installed, use the -qlp option in the rpm command.

        $ rpm -qlp pkgship-2.2.0-10.oe2203sp2.noarch.rpm
        /etc/ima/digest_lists.tlv/0-metadata_list-compact_tlv-pkgship-2.2.0-10.oe2203sp2.noarch
        /etc/ima/digest_lists/0-metadata_list-compact-pkgship-2.2.0-10.oe2203sp2.noarch
        /etc/pkgship/auto_install_pkgship_requires.sh
        /etc/pkgship/conf.yaml
        /etc/pkgship/package.ini
        ......
        

        Querying RPM Package Dependencies

        To query the list of dependency packages compiled by a specified RPM package that is not installed, use the -qRp option in the rpm command.

        $ rpm -qRp pkgship-2.2.0-10.oe2203sp2.noarch.rpm
        /bin/bash
        /bin/sh
        /usr/bin/python3
        config(pkgship) = 2.2.0-10.oe2203sp2
        python3
        python3-Flask-Limiter
        ......
        

        Verifying All Installed RPM Packages

        To verify an installed RPM package, use the -Va option in the rpm command to compare the information about the files installed in the package with the information about the files obtained from the package metadata stored in the RPM database.

        $ rpm -Va
        S.5....T.  c /root/.bashrc
        .......T.  c /etc/yum.repos.d/openEuler.repo
        S.5....T.  c /etc/issue
        S.5....T.  c /etc/issue.net
        S.5....T.  c /etc/csh.login
        S.5....T.  c /etc/profile
        .M....G..  g /var/log/lastlog
        .M.......  c /boot/grub2/grubenv
        ......
        

        Output fields of the rpm -Va command and their meanings

        FieldDescription
        SThe file length changes.
        MThe access permission or type of a file changes.
        5The MD5 checksum changes.
        DThe attributes of a device node change.
        LThe symbolic link of a file changes.
        UThe owner of a file, subdirectory, or device node changes.
        GThe group of a file, subdirectory, or device node changes.
        TThe last modification time of a file changes.

        Querying the RPM Package of a Specific File

        To query an RPM package that provides a specific binary file on Linux, use the -qf option in the rpm command.

        $ rpm -qf /usr/share/doc/pkgship
        pkgship-2.2.0-10.oe2203sp2.noarch.rpm
        

        Querying Files in an Installed RPM Package

        To query the list of installation files of an RPM package, use the -ql option in the rpm command.

        $ rpm -ql dnf
        /etc/bash_completion.d/dnf
        /etc/ima/digest_lists.tlv/0-metadata_list-compact_tlv-dnf-4.14.0-14.oe2203sp2.noarch
        /etc/ima/digest_lists/0-metadata_list-compact-dnf-dnf-4.14.0-14.oe2203sp2.noarch
        /usr/bin/dnf
        /usr/lib/systemd/system/dnf-makecache.service
        /usr/lib/systemd/system/dnf-makecache.timer
        /usr/share/doc/dnf
        /usr/share/doc/dnf/AUTHORS
        /usr/share/doc/dnf/README.rst
        /usr/share/licenses/dnf
        /usr/share/licenses/dnf/COPYING
        /usr/share/licenses/dnf/PACKAGE-LICENSING
        /var/cache/dnf
        

        Querying the Recently Installed RPM Packages

        Linux is a multi-user OS. During the use of Linux, other users may have installed some software packages. To query the recently installed packages in the system, use the -qa --last options in the rpm command.

        $ rpm -qa --last
        ntp-4.2.8p15-11.oe2203sp2.x86_64
        ntpstat-0.6-4.oe2203sp2.noarch
        ntp-help-4.2.8p15-11.oe2203sp2.noarch
        

        Querying Only the Documents of the Installed RPM Packages

        You can obtain the help information of any command from the Linux Man page (path for storing /usr/share/doc/Package_Name-Version_Number/docs* documents). To query the list of documents associated with the installed RPM packages, use the -qdf option in the rpm command and enter the binary file path.

        $ rpm -qdf /usr/bin/grep
        /usr/share/doc/grep/NEWS
        /usr/share/doc/grep/README
        /usr/share/doc/grep/THANKS
        /usr/share/doc/grep/TODO
        /usr/share/info/grep.info.gz
        /usr/share/man/man1/egrep.1.gz
        /usr/share/man/man1/fgrep.1.gz
        /usr/share/man/man1/grep.1.gz
        

        Upgrading an Installed RPM Package

        You can easily upgrade the installed RPM package to the latest version by using the -Uvh option and the rpm command.

        $ rpm -Uvh pkgship-2.2.0-10.oe2203sp2.noarch.rpm
        Preparing...        ################################# [100%]
        

        Note: When the installed RPM package is upgraded, the old RPM package is deleted and the new RPM package is installed.

        Removing an Installed RPM Package

        To remove an RPM package installed on the system, use the -ev or -e option in the rpm command.

        rpm -ev pkgship
        

        Rebuilding the Damaged RPM Database

        When you try to update the system using the yum update command, you may receive an error message indicating that the RPM database is damaged. If you receive this message, use the --rebuilddb option in the rpm command to rebuild the database.

        rm /var/lib/rpm/__db*
        rpm --rebuilddb
        

        Checking Whether Vulnerabilities in Specific Packages Have Been Fixed

        You can use the --changelog option in the rpm command and enter the corresponding CVE ID.

        rpm -q --changelog python-2.6.6 | grep -i "CVE-2019-9636"
        

        Importing the RPM GPG Key

        By default, when a new repository is added to the Linux system, the GPG key is automatically imported. You can also use --import in the rpm command to manually import the RPM GPG key to check the integrity of a package when downloading it from the repository.

        rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-OpenEuler-22.03-LTS-SP2
        
      3. DNF commands

        DNF commands

        CommandDescription
        repolistDisplays the configured software repository source.
        installInstalls one or more software packages on Linux.
        upgradeUpgrades one or more software packages on Linux.
        listLists a software package or a group of software packages.
        infoDisplays detailed information about a package or package group.
        updateinfoDisplays the bulletin information about a package.
        searchSearches for the specified character string in the software package details.
        check-updateChecks for software package update.
        removeRemoves one or more software packages from the system.
        reinstallReinstalls a package.
        downgradeDowngrades a software package.
        autoremoveRemoves all unnecessary software packages that are installed due to dependency relationships.
        distro-syncSynchronizes the installed software package to the latest available version.
        makecacheCreates a metadata cache.
        repository-packageRuns commands on all software packages in a specified repository.
        providesSearches for the software package that provides the specified content.
        groupDisplays or uses group information.
        historyDisplays or uses transaction history.
        cleanDeletes cached data.

        Displaying Configured Software Repositories

        By default, the --enabled option is added to display the enabled software repositories.

        $ dnf repolist --enabled
        repo id                                                                   repo name
        EPOL                                                                      EPOL
        OS                                                                        OS
        debuginfo                                                                 debuginfo
        everything                                                                everything
        pkgship_elasticsearch                                                     Elasticsearch repositor
        source                                                                    source
        update                                                                    update
        
        • --all: displays all software repositories.
        • --disabled: displays disabled software repositories.
        • --enabled: displays enabled repositories (default).

        Installing One or More Software Packages

        You can run the install command to install RPM packages.

        dnf install software_package
        

        Conflicting packages or packages that cannot be installed may exist during software package installation. You can add --allowerasing to the command to replace the conflicting packages or --skip-broken to skip the packages that cannot be installed.

        dnf install software_package [software_package ...] --allowerasing --skip-broken
        

        When dnf is used to install a software package, add --installroot to set the root directory for installing the software package.

        dnf install software_package --installroot software_package_root_directory
        

        If you need to temporarily specify a repository source for installation, you can add the --setopt=reposdir= option to specify the loading directory of the repository source.

        dnf install software_package --setopt=reposdir=repo_source_directory
        

        If interactive confirmation is not required during installation, you can add -y or --assumeyes to enable all software packages to be installed to automatically answer Yes.

        dnf install software_package -y
        

        To install an RPM package by specifying a specific repository source, you can specify the --repo or --enablerepo option. To achieve the same effect, you can also use the --disablerepo option to disable the matched repository source. You are advised to use the --repo option to install the RPM package.

        dnf install software_package --repo=repo_source_
        

        Reinstalling a Software Package

        You can run the reinstall command to reinstall a software package in the system.

        dnf reinstall software_package
        

        Upgrading One or More Software Packages

        • You can use the upgrade command to upgrade one or more software packages on Linux.
        dnf upgrade software_package [software_package ...]
        
        • You can also run the update command to upgrade one or more software packages.
        dnf update software_package [software_package ...]
        

        Downgrading a Software Package

        If a compatibility problem occurs because the version of a software package is too late, you can downgrade the software package.

        dnf downgrade software_package
        

        Listing a Package or a Group of Packages

        You can run the list command to list the software packages installed in the system and the software packages in the configured repository.

        dnf list
        

        You can add options to filter the displayed package list.

        • --all: displays all software packages (default).
        • --available: displays only available software packages.
        • --installed: displays only installed software packages.
        • --extras: displays only additional software packages.
        • --updates: displays only the software packages to be upgraded.
        • --upgrades: displays only the software packages to be upgraded.
        • --autoremove: displays only the software packages to be removed.
        • --recent: displays the software packages that have been changed recently.

        Querying Details About a Software Package

        You can run the info command to query details about a software package.

        dnf info software_package
        

        Searching for a Software Package

        If you need to install a software package in the system but you are not sure about the full name of the software package, you can run the search command to search for the matched package.

        dnf search software_package
        

        Uninstalling One or More Software Packages

        You can run the remove command to remove an expired or duplicate software package.

        dnf remove software_package
        
        • --duplicates: removes installed (duplicate) software packages.
        • --oldinstallonly: removes expired installation-only software packages.

        Automatically Removing Software Packages Installed Due to Dependency Relationships

        You can run the autoremove command to remove unnecessary software packages that are installed due to dependency relationships.

        dnf autoremove software_package
        

      Configuring SSH

      1. Introduction to the SSH service

        Secure Shell (SSH) is a reliable protocol that ensures the security of remote login sessions and other network services. The SSH protocol can effectively prevent information leakage during remote management. SSH encrypts transferred data to prevent domain name server (DNS) spoofing and IP spoofing. OpenSSH was created as an open source alternative to the proprietary SSH protocol.

      2. Configuring the SSH Service

        # Open and modify the /etc/ssh/sshd_config file.
        vi /etc/ssh/sshd_config
        
        # Restart the SSH service.
        systemctl restart sshd
        
        # Check the SSH service status.
        systemctl status sshd
        
      3. Main options in the SSH service configuration file

        $ Specify the SSH protocol version.
        Protocol 2
        
        # Allowed users
        AllowUsers xxx
        
        # Denied users
        DenyUser root
        
        # Configure session timeout.
        ClientAliveInterval 120
        
        # Disable SSH root login.
        PermitRootLogin no
        
        # Configure or change the SSH port number.
        Port 1234
        
        # Disable SSH password authentication.
        PasswordAuthentication no
        

      Bug Catching

      Buggy Content

      Bug Description

      Submit As Issue

      It's a little complicated....

      I'd like to ask someone.

      PR

      Just a small problem.

      I can fix it online!

      Bug Type
      Specifications and Common Mistakes

      ● Misspellings or punctuation mistakes;

      ● Incorrect links, empty cells, or wrong formats;

      ● Chinese characters in English context;

      ● Minor inconsistencies between the UI and descriptions;

      ● Low writing fluency that does not affect understanding;

      ● Incorrect version numbers, including software package names and version numbers on the UI.

      Usability

      ● Incorrect or missing key steps;

      ● Missing prerequisites or precautions;

      ● Ambiguous figures, tables, or texts;

      ● Unclear logic, such as missing classifications, items, and steps.

      Correctness

      ● Technical principles, function descriptions, or specifications inconsistent with those of the software;

      ● Incorrect schematic or architecture diagrams;

      ● Incorrect commands or command parameters;

      ● Incorrect code;

      ● Commands inconsistent with the functions;

      ● Wrong screenshots.

      Risk Warnings

      ● Lack of risk warnings for operations that may damage the system or important data.

      Content Compliance

      ● Contents that may violate applicable laws and regulations or geo-cultural context-sensitive words and expressions;

      ● Copyright infringement.

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