RHEL-based

Contents

RHEL-based

About

Red Hat

Short facts

In 1993, Company founded
In 2012, Red Hat became the first open source technology company to surpass more than $1 billion in revenue
In 2019, IBM acquired Red Hat for approximately US$34 billion, the largest software acquisition in history
More than 100 locations in more than 40 countries

Some links

Fedora vs. CentOS vs. RHEL

All

Pros

Cons

Slow graphical installer

RHEL

Red Hat Enterprise Linux

Pros

Support
- allows SLAs (increase availability)
- performance optimizations
Updates
Access to knowledge base
High-security
- faster reactions
- security announcements
Proprietary goodies
Flavors (workstation, server, …)

Cons

Cost

Fedora

The Fedora Project releases a new version of Fedora approximately every 6 months and provides updated packages (maintenance) to these releases for approximately 13 months. This allows users to "skip a release" while still being able to always have a system that is still receiving updates.

Pros

Latest Software
Easy mayor release upgrades
Cost
Ahead of RHEL

Cons

Unstable with less testing
Fast release cycles

CentOS

from Community Enterprise Operating System

Until 2021 CentOS has been available as the classical release based CentOS Linux and the rolling CentOS Stream. Nowadays only the stream is available.

CentOS Linux

DEVELOPMENT DISCONTINUED DECEMBER 2021
END OF LIFE -Jun 30th, 2024

https://www.centos.org/centos-linux/

Consistent, manageable platform that suits a wide variety of deployments.# For some open source communities, it is a solid, predictable base to build upon

CentOS Product Specifications

Each CentOS version is maintained until the equivalent RHEL version goes out of general support. A new CentOS version is made available once a new RHEL version is rebuilt - approximately every 6-12 months for minor point releases and several years for major version bumps. The length of time the rebuild takes varies from weeks for point releases to months for major version bumps. This results in a secure, low-maintenance, reliable, predictable and reproducible Linux environment.

Pros

Stable, mature
Cost

Cons

Mature/old/antique software
Mayor release upgrades are complicated
Only 3rd-party support
Lags a little behind RHEL
- Releases 1-2 month
- Security updates (1 day) behind

CentOS Stream

Rolling-release distro that tracks just ahead of Red Hat Enterprise Linux (RHEL) development, positioned as a midstream between Fedora Linux and RHEL. For anyone interested in participating and collaborating in the RHEL ecosystem, CentOS Stream is your reliable platform for innovation.

Pros

Stable, mature enough
Rolling release with low maintenance
Cost
Lags only little behind RHEL
- Security updates (1 day) behind

Cons

Only 3rd-party support
Stream 9 installer DVD with kernel panic (on ProxMox)
CentOS 8 Stream has a very scrappy graphical installer (anaconda)
- NIC is not enabled by default
- Partitioning menu is frustrating
  - resets the entries
  - no btrfs support

Rocky Linux

Pros

Offer 10 years of support for a major release
Wiki EN Rocky Linux

Alma Linux

Pros

Offer 10 years of support for a major release
Wiki EN Alma Linux

CentOS Stream

Prepare DHCP/DNS-server
Prepare firewall/proxy to access repository
Chose your language
Switch on network card and configure the hostname
- This is necessary to download the metadata from the repository.
- (optional) Check internet access via shell
  1. CTRL+ALT+F1 #tmux console
  2. curl rockstable.it
  3. CTRL+ALT+F6 #graphical installer
Configure repository
Define a administrative user (group wheel)
(optional) Set Root password
(optional) Create a user
(optional) Change partitioning
Set time zone
Select software profile. Probably:
- Minimal installation
- Guest agents
- Headless management
- System tools
Install

The installer was quite disappointing to me.

Check that centos-release-stream.x86_64 is installed.

   1 rpm -qi centos-release-stream.x86_64

Repositories

Default Repositories

List enabled repos
dnf repolist

   1 repo id                        repo name
   2 appstream                      CentOS Stream 8 - AppStream
   3 baseos                         CentOS Stream 8 - BaseOS
   4 extras                         CentOS Stream 8 - Extras

Additional Repositories

CentOS Wiki Additional Repositories

List all packages in repo extras
dnf repository-packages extras list

   1 Last metadata expiration check: 0:38:58 ago on Tue 22 Sep 2020 04:30:55 PM CEST.
   2 Available Packages
   3 centos-release-advanced-virtualization.noarch     1.0-1.el8               extras
   4 centos-release-ansible-29.noarch                  1-2.el8                 extras
   5 centos-release-ceph-nautilus.noarch               1.2-2.el8               extras
   6 centos-release-ceph-octopus.noarch                1.0-1.el8               extras
   7 centos-release-configmanagement.noarch            1-1.el8                 extras
   8 centos-release-gluster6.noarch                    1.0-1.el8               extras
   9 centos-release-gluster7.noarch                    1.0-2.el8               extras
  10 centos-release-messaging.noarch                   1-2.el8                 extras
  11 centos-release-nfs-ganesha28.noarch               1.0-3.el8               extras
  12 centos-release-nfs-ganesha30.noarch               1.0-2.el8               extras
  13 centos-release-openstack-train.noarch             2-1.el8                 extras
  14 centos-release-openstack-ussuri.noarch            1-3.el8                 extras
  15 centos-release-opstools.noarch                    1-10.el8                extras
  16 centos-release-qpid-proton.noarch                 1-2.el8                 extras
  17 centos-release-rabbitmq-38.noarch                 1-2.el8                 extras
  18 centos-release-storage-common.noarch              2-2.el8                 extras
  19 centos-release-stream.x86_64                      8.1-1.1911.0.7.el8      extras
  20 centos-release-virt-common.noarch                 1-2.el8                 extras
  21 cpaste.x86_64                                     1.0.0-3.el8             extras
  22 elrepo-release.noarch                             8.1-1.el8.elrepo        extras
  23 epel-release.noarch                               8-8.el8                 extras

EPEL

Extra Packages for Enterprise Linux (EPEL)

Install epel-release

   1 dnf install epel-release.noarch
   2 #dnf install "https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm"
   3

Software Collections

Software Collections is available for Red Hat Enterprise Linux 7 and previous supported releases. Starting with Red Hat Enterprise Linux 8, the content traditionally consumed via Software Collections is now part of Application Streams. Please see the Application Streams Life Cycle documentation for that release.

Install python3 from the software-collections (SCL) repository longaside to platform-python, which is used for the system utilities.

   1 dnf install centos-release-scl

Install essential packages

Install essential packages (EPEL required)

   1 dnf install \
   2         bash-completion byobu ca-certificates curl \
   3         dmidecode bind-utils dosfstools ethtool git gpm hdparm htop iftop info \
   4         iotop jq lsof man-db mc mlocate net-tools openssl \
   5         parted pigz psmisc pv pwgen rsync screen sqlite strace \
   6         sudo sysstat tcpdump tmux util-linux-user vim wget zsh

The signing key used for the repositories must be confirmed on first manually. The user must check the fingerprint e.g. on PGP key-server 0x8483C65D. Oh, "selfsig" and "Alexey Omelchenko" signed the key. Where is the link to the web of trust? 0,o

   1 (59/62): tmux-2.7-1.el8.x86_64.rpm                                                    71 MB/s | 317 kB     00:00    
   2 (60/62): zsh-5.5.1-6.el8_1.2.x86_64.rpm                                               76 MB/s | 2.9 MB     00:00    
   3 (61/62): vim-enhanced-8.0.1763-13.el8.x86_64.rpm                                      3.8 MB/s | 1.4 MB    00:00    
   4 (62/62): vim-common-8.0.1763-13.el8.x86_64.rpm                                        13 MB/s | 6.3 MB     00:00    
   5 ----------------------------------------------------------------------------------------------------------------
   6 Total                                                                                                                                                                                                                                                                 25 MB/s |  31 MB     00:01     
   7 warning: /var/cache/dnf/AppStream-a520ed22b0a8a736/packages/SDL-1.2.15-37.el8.x86_64.rpm:
   8 Header V3 RSA/SHA256 Signature, key ID 8483c65d: NOKEY
   9 CentOS-8 - AppStream                                                                                                                                                                                                                                                 209 kB/s | 1.6 kB     00:00    
  10 Importing GPG key 0x8483C65D:
  11  Userid     : "CentOS (CentOS Official Signing Key) <security@centos.org>"
  12  Fingerprint: 99DB 70FA E1D7 CE22 7FB6 4882 05B5 55B3 8483 C65D
  13  From       : /etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
  14 Is this ok [y/N]: y
  15 Key imported successfully
  16 Running transaction check
  17 Transaction check succeeded.
  18 Running transaction test
  19 Transaction test succeeded.
  20 Running transaction
  21   Preparing        :                                                                  1/1 
  22   Installing       : perl-Exporter-5.72-396.el8.noarch                                1/62 
  23   Installing       : perl-libs-4:5.26.3-416.el8.x86_64                                2/62 
  24 …

Automatic upgrades

yum-cron

dnf-automatic

Red Hat Enterprise Linux 9 - Chapter 7. Automating software updates in RHEL 9

Install dnf-automatic

   1 rpm -qi dnf-automatic
   2 dnf install dnf-automatic

The config is located in
/etc/dnf/automatic.conf
(enable comments to view the file)

   1 [commands]
   2 #  What kind of upgrade to perform:
   3 # default                            = all available upgrades
   4 # security                           = only the security upgrades
   5 upgrade_type = default
   6 random_sleep = 0
   7 
   8 # Maximum time in seconds to wait until the system is on-line and able to
   9 # connect to remote repositories.
  10 network_online_timeout = 60
  11 
  12 # To just receive updates use dnf-automatic-notifyonly.timer
  13 
  14 # Whether updates should be downloaded when they are available, by
  15 # dnf-automatic.timer. notifyonly.timer, download.timer and
  16 # install.timer override this setting.
  17 download_updates = yes
  18 
  19 # Whether updates should be applied when they are available, by
  20 # dnf-automatic.timer. notifyonly.timer, download.timer and
  21 # install.timer override this setting.
  22 apply_updates = yes
  23 
  24 
  25 [emitters]
  26 # Name to use for this system in messages that are emitted.  Default is the
  27 # hostname.
  28 # system_name = my-host
  29 
  30 # How to send messages.  Valid options are stdio, email and motd.  If
  31 # emit_via includes stdio, messages will be sent to stdout; this is useful
  32 # to have cron send the messages.  If emit_via includes email, this
  33 # program will send email itself according to the configured options.
  34 # If emit_via includes motd, /etc/motd file will have the messages. if
  35 # emit_via includes command_email, then messages will be send via a shell
  36 # command compatible with sendmail.
  37 # Default is email,stdio.
  38 # If emit_via is None or left blank, no messages will be sent.
  39 emit_via = stdio
  40 
  41 
  42 [email]
  43 # The address to send email messages from.
  44 email_from = root@example.com
  45 
  46 # List of addresses to send messages to.
  47 email_to = root
  48 
  49 # Name of the host to connect to to send email messages.
  50 email_host = localhost
  51 
  52 
  53 [command]
  54 # The shell command to execute. This is a Python format string, as used in
  55 # str.format(). The format function will pass a shell-quoted argument called
  56 # `body`.
  57 # command_format = "cat"
  58 
  59 # The contents of stdin to pass to the command. It is a format string with the
  60 # same arguments as `command_format`.
  61 # stdin_format = "{body}"
  62 
  63 
  64 [command_email]
  65 # The shell command to use to send email. This is a Python format string,
  66 # as used in str.format(). The format function will pass shell-quoted arguments
  67 # called body, subject, email_from, email_to.
  68 # command_format = "mail -Ssendwait -s {subject} -r {email_from} {email_to}"
  69 
  70 # The contents of stdin to pass to the command. It is a format string with the
  71 # same arguments as `command_format`.
  72 # stdin_format = "{body}"
  73 
  74 # The address to send email messages from.
  75 email_from = root@example.com
  76 
  77 # List of addresses to send messages to.
  78 email_to = root
  79 
  80 
  81 [base]
  82 # This section overrides dnf.conf
  83 
  84 # Use this to filter DNF core messages
  85 debuglevel = 1

No modification (besides the email addresses) needed the mode can be selected using a specific timer unit.

The service units are static and have no [Install] section. They are ment to be called by timers when the time arrives.

Timer units

Timer unit	Function	Overrides `apply_updates` and `download_updates`
`dnf-automatic-download.timer`	Update cache and download	Yes
`dnf-automatic-install.timer`	Update cache, download and install	Yes
`dnf-automatic-notifyonly.timer`	Update cache and notify	Yes
`dnf-automatic.timer`	Behavior depends on `/etc/dnf/automatic.conf`	No

Enable dnf-automatic-install.timer

   1 % systemctl enable --now dnf-automatic-install.timer
   2 Created symlink /etc/systemd/system/timers.target.wants/dnf-automatic-install.timer → /usr/lib/systemd/system/dnf-automatic-install.timer.

Please don't wait and wonder. It will start the next day.

Verify

   1 % systemctl status dnf-automatic-install.timer
   2 % systemctl list-timers --all

Configure zsh

Needs python3

   1 dnf repoquery --whatprovides python3
   2 Last metadata expiration check: 2:27:05 ago on Tue 22 Sep 2020 04:30:55 PM CEST.
   3 python36-0:3.6.8-2.module_el8.3.0+389+6a62c88d.x86_64
   4 dnf install python3

   1 git clone git://git.grml.org/grml-etc-core.git /opt/grml-etc-core
   2 ln -s /opt/grml-etc-core/etc/zsh /etc/zsh
   3 echo -e '\n[ -f "/etc/zsh/zshrc" ] && \\\n\tsource "/etc/zsh/zshrc"' >> /etc/zshrc
   4 chsh -s /bin/zsh
   5 exec zsh

hostname

Manpage of SystemD hostnamectl

   1 man hostnamectl

Check hostname with hostnamectl

   1    Static hostname: localhost.localdomain
   2 Transient hostname: ipa1
   3          Icon name: computer-vm
   4            Chassis: vm
   5         Machine ID: bd9f9c9446c643fd86c3d283cad1a5ea
   6            Boot ID: 960f855492ce4b3b9a02e38424a25734
   7     Virtualization: kvm
   8   Operating System: CentOS Stream 8
   9        CPE OS Name: cpe:/o:centos:centos:8
  10             Kernel: Linux 4.18.0-236.el8.x86_64
  11       Architecture: x86-64

Set hostname if you only got a transient one

   1 hostnamectl set-hostname ipa1.2a.rockstable.it

Check again

   1 hostnamectl
   2    Static hostname: ipa1.2a.rockstable.it
   3          Icon name: computer-vm
   4            Chassis: vm
   5         Machine ID: bd9f9c9446c643fd86c3d283cad1a5ea
   6            Boot ID: 960f855492ce4b3b9a02e38424a25734
   7     Virtualization: kvm
   8   Operating System: CentOS Stream 8
   9        CPE OS Name: cpe:/o:centos:centos:8
  10             Kernel: Linux 4.18.0-236.el8.x86_64
  11       Architecture: x86-64

yum and dnf

Group

The package management offers groups of packages

   1 root@ipa1 ~ # dnf group
   2 Last metadata expiration check: 0:39:39 ago on Thu 24 Sep 2020 10:33:06 AM CEST.
   3 Installed Groups: 2
   4 Available Groups: 10
   5 root@ipa1 ~ # dnf group list
   6 dnf group list -v         
   7 …
   8 Available Environment Groups:
   9    Server with GUI (graphical-server-environment)
  10    Minimal Install (minimal-environment)
  11    Workstation (workstation-product-environment)
  12    Virtualization Host (virtualization-host-environment)
  13    Custom Operating System (custom-environment)
  14 Installed Environment Groups:
  15    Server (server-product-environment)
  16 Installed Groups:
  17    Headless Management (headless-management)
  18    System Tools (system-tools)
  19 Available Groups:
  20    Container Management (container-management)
  21    .NET Core Development (dotnet-core)
  22    RPM Development Tools (rpm-development-tools)
  23    Development Tools (development)
  24    Graphical Administration Tools (graphical-admin-tools)
  25    Legacy UNIX Compatibility (legacy-unix)
  26    Network Servers (network-server)
  27    Scientific Support (scientific)
  28    Security Tools (security-tools)
  29    Smart Card Support (smart-card)

The package management offers and even more hidden groups of packages.

   1 root@ipa1 ~ # dnf group --hidden
   2 Last metadata expiration check: 0:39:43 ago on Thu 24 Sep 2020 10:33:06 AM CEST.
   3 Installed Groups: 6
   4 Available Groups: 61
   5 root@ipa1 ~ #  dnf group list --hidden -v
   6 …
   7 Available Environment Groups:
   8    Server with GUI (graphical-server-environment)
   9    Minimal Install (minimal-environment)
  10    Workstation (workstation-product-environment)
  11    Virtualization Host (virtualization-host-environment)
  12    Custom Operating System (custom-environment)
  13 Installed Environment Groups:
  14    Server (server-product-environment)
  15 Installed Groups:
  16    Core (core)
  17    Hardware Support (hardware-support)
  18    Headless Management (headless-management)
  19    Server product core (server-product)
  20    Standard (standard)
  21    System Tools (system-tools)
  22 Available Groups:
  23    Backup Client (backup-client)
  24    base-x (base-x)
  25    Conflicts AppStream (conflicts-appstream)
  26    Container Management (container-management)
  27    Debugging Tools (debugging)
  28    Desktop Debugging and Performance Tools (desktop-debugging)
  29    .NET Core Development (dotnet-core)
  30    FTP Server (ftp-server)
  31    GNOME Applications (gnome-apps)
  32    Graphics Creation Tools (graphics)
  33    Guest Agents (guest-agents)
  34    Guest Desktop Agents (guest-desktop-agents)
  35    Input Methods (input-methods)
  36    Internet Applications (internet-applications)
  37    Internet Browser (internet-browser)
  38    Java Platform (java-platform)
  39    Legacy X Window System Compatibility (legacy-x)
  40    Multimedia (multimedia)
  41    Office Suite and Productivity (office-suite)
  42    Atomic Host ostree support (ostree-support)
  43    KVM platform specific packages (platform-kvm)
  44    Hyper-v platform specific packages (platform-microsoft)
  45    VMware platform specific packages (platform-vmware)
  46    Printing Client (print-client)
  47    Remote Desktop Clients (remote-desktop-clients)
  48    RPM Development Tools (rpm-development-tools)
  49    TeX formatting system (texlive)
  50    Virtualization Client (virtualization-client)
  51    Virtualization Hypervisor (virtualization-hypervisor)
  52    Virtualization Platform (virtualization-platform)
  53    Virtualization Tools (virtualization-tools)
  54    Basic Web Server (web-server)
  55    Additional Development (additional-devel)
  56    Anaconda tools (anaconda-tools)
  57    Base (base)
  58    Conflicts BaseOS (conflicts-baseos)
  59    Development Tools (development)
  60    Dial-up Networking Support (dial-up)
  61    File and Storage Server (file-server)
  62    Fonts (fonts)
  63    GNOME (gnome-desktop)
  64    Graphical Administration Tools (graphical-admin-tools)
  65    Hardware Monitoring Utilities (hardware-monitoring)
  66    Infiniband Support (infiniband)
  67    Large Systems Performance (large-systems)
  68    Legacy UNIX Compatibility (legacy-unix)
  69    Mail Server (mail-server)
  70    Mainframe Access (mainframe-access)
  71    Network File System Client (network-file-system-client)
  72    Network Servers (network-server)
  73    Networking Tools (network-tools)
  74    Common NetworkManager submodules (networkmanager-submodules)
  75    Performance Tools (performance)
  76    Platform Development (platform-devel)
  77    Python Web (python-web)
  78    Remote Management for Linux (remote-system-management)
  79    Scientific Support (scientific)
  80    Security Tools (security-tools)
  81    Smart Card Support (smart-card)
  82    Windows File Server (smb-server)
  83    Workstation product core (workstation-product)

I don't exactly know why the option --hidden and other useful filters like --ids or --installed are mutually exclusive, but -v does the job too. That's probably a logical bug.

   1 Command line error: argument --hidden: not allowed with argument --ids

These pretty names with spaces are not convinient on the cli ("System Tools").

Groups can depend on packages or other groups

   1 root@ipa1 ~ # dnf group info "System Tools"
   2 Last metadata expiration check: 0:10:47 ago on Thu 24 Sep 2020 10:33:06 AM CEST.
   3 
   4 Group: System Tools
   5  Description: This group is a collection of various tools for the system, such as the client for connecting to SMB shares and tools to monitor network traffic.                                                                                                                                     
   6  Default Packages:
   7    NetworkManager-libreswan
   8    chrony
   9    cifs-utils
  10    libreswan
  11    nmap
  12    openldap-clients
  13    samba-client
  14    setserial
  15    tigervnc
  16    tmux
  17    xdelta
  18    zsh
  19  Optional Packages:
  20    PackageKit-command-not-found
  21    aide
  22    amanda-client
  23    arpwatch
  24    autofs
  25    chrpath
  26    convmv
  27    createrepo_c
  28    environment-modules
  29    freerdp
  30    fuse
  31    gpm
  32    gssdp
  33    gupnp
  34    hardlink
  35    iotop
  36    lzop
  37    mc
  38    mrtg
  39    mtx
  40    net-snmp-utils
  41    oddjob
  42    oddjob-mkhomedir
  43    pmdk-convert
  44    rear
  45    speech-dispatcher
  46    speech-dispatcher-espeak-ng
  47    sysstat
  48    wireshark
  49    x3270-x11
  50 
  51 root@ipa1 ~ # dnf group info "Server"
  52 Last metadata expiration check: 0:11:54 ago on Thu 24 Sep 2020 10:33:06 AM CEST.
  53 Environment Group: Server
  54  Description: An integrated, easy-to-manage server.
  55 no group 'dns-server' from environment 'server-product-environment'
  56  Mandatory Groups:
  57    Container Management
  58    Core
  59    Hardware Support
  60    Headless Management
  61    Server product core
  62    Standard
  63  Optional Groups:
  64    Basic Web Server
  65    Debugging Tools
  66    FTP Server
  67    File and Storage Server
  68    GNOME
  69    Guest Agents
  70    Hardware Monitoring Utilities
  71    Infiniband Support
  72    Mail Server
  73    Network File System Client
  74    Network Servers
  75    Performance Tools
  76    Remote Management for Linux
  77    Virtualization Hypervisor
  78    Windows File Server

I'm not convinced of the top-level groups, but there are some very useful hidden groups, i guess.

Hidden groups?

Modularity

Yeah, it's getting more complicated. CentOS 8 has a brand new feature "modularity"
https://docs.pagure.org/modularity/

Man pages

   1 man dnf
   2 man dnf.modularity

List modules

   1 root@ipa1 ~ # dnf module list
   2 Last metadata expiration check: 0:41:05 ago on Thu 24 Sep 2020 11:28:11 AM CEST.
   3 CentOS Stream 8 - AppStream
   4 Name                 Stream       Profiles                              Summary
   5 389-ds               1.4 [e]                                            389 Directory Server (base)
   6 ant                  1.10 [d]     common [d]                            Java build tool
   7 container-tools      rhel8 [d]    common [d]                            Common tools and dependencies for container runtimes
   8 container-tools      1.0          common [d]                            Common tools and dependencies for container runtimes
   9 container-tools      2.0          common [d]                            Common tools and dependencies for container runtimes
  10 freeradius           3.0 [d]      server [d]                            High-performance and highly configurable free RADIUS server
  11 gimp                 2.8 [d]      common [d], devel                     gimp module
  12 go-toolset           rhel8 [d]    common [d]                            Go
  13 httpd                2.4 [d][e]   common [d], devel, minimal            Apache HTTP Server
  14 idm                  DL1 [e]      adtrust, client, common [d], dns, ser The Red Hat Enterprise Linux Identity Management system module
  15                                   ver
  16 idm                  client [d]   common [d]                            RHEL IdM long term support client module
  17 inkscape             0.92.3 [d]   common [d]                            Vector-based drawing program using SVG
  18 javapackages-runtime 201801 [d]   common [d]                            Basic runtime utilities to support Java applications
  19 jmc                  rhel8 [d]    common [d], core                      Java Mission Control is a profiling and diagnostics tool for the Hotspot J
  20                                                                         VM
  21 libselinux-python    2.8          common                                Python 2 bindings for libselinux
  22 llvm-toolset         rhel8 [d]    common [d]                            LLVM
  23 mailman              2.1 [d]      common [d]                            Electronic mail discussion and e-newsletter lists managing software
  24 mariadb              10.3 [d]     client, galera, server [d]            MariaDB Module
  25 maven                3.5 [d]      common [d]                            Java project management and project comprehension tool
  26 maven                3.6          common [d]                            Java project management and project comprehension tool
  27 mercurial            4.8 [d]      common [d]                            Mercurial -- a distributed SCM
  28 mod_auth_openidc     2.3                                                Apache module suporting OpenID Connect authentication
  29 mysql                8.0 [d]      client, server [d]                    MySQL Module
  30 nginx                1.14 [d]     common [d]                            nginx webserver
  31 nginx                1.16         common [d]                            nginx webserver
  32 nginx                1.18         common [d]                            nginx webserver
  33 nodejs               10 [d]       common [d], development, minimal, s2i Javascript runtime
  34 nodejs               12           common [d], development, minimal, s2i Javascript runtime
  35 nodejs               14           common [d], development, minimal, s2i Javascript runtime
  36 parfait              0.5          common                                Parfait Module
  37 perl                 5.24         common [d], minimal                   Practical Extraction and Report Language
  38 perl                 5.26 [d][e]  common [d], minimal                   Practical Extraction and Report Language
  39 perl                 5.30         common [d], minimal                   Practical Extraction and Report Language
  40 perl-App-cpanminus   1.7044 [d]   common [d]                            Get, unpack, build and install CPAN modules
  41 perl-DBD-MySQL       4.046 [d]    common [d]                            A MySQL interface for Perl
  42 perl-DBD-Pg          3.7 [d]      common [d]                            A PostgreSQL interface for Perl
  43 perl-DBD-SQLite      1.58 [d]     common [d]                            SQLite DBI driver
  44 perl-DBI             1.641 [d]    common [d]                            A database access API for Perl
  45 perl-FCGI            0.78 [d]     common [d]                            FastCGI Perl bindings
  46 perl-IO-Socket-SSL   2.066 [d][e] common [d]                            Perl library for transparent TLS
  47 perl-YAML            1.24 [d]     common [d]                            Perl parser for YAML
  48 perl-libwww-perl     6.34 [d][e]  common [d]                            A Perl interface to the World-Wide Web
  49 php                  7.2 [d]      common [d], devel, minimal            PHP scripting language
  50 php                  7.3          common [d], devel, minimal            PHP scripting language
  51 php                  7.4          common [d], devel, minimal            PHP scripting language
  52 pki-core             10.6 [e]                                           PKI Core module for PKI 10.6 or later
  53 pki-deps             10.6 [e]                                           PKI Dependencies module for PKI 10.6 or later
  54 postgresql           9.6          client, server [d]                    PostgreSQL server and client module
  55 postgresql           10 [d]       client, server [d]                    PostgreSQL server and client module
  56 postgresql           12           client, server [d]                    PostgreSQL server and client module
  57 python27             2.7 [d]      common [d]                            Python programming language, version 2.7
  58 python36             3.6 [d][e]   build, common [d]                     Python programming language, version 3.6
  59 python38             3.8 [d]      build, common [d]                     Python programming language, version 3.8
  60 redis                5 [d]        common [d]                            Redis persistent key-value database
  61 rhn-tools            1.0 [d]      common [d]                            Red Hat Satellite 5 tools for RHEL
  62 ruby                 2.5 [d]      common [d]                            An interpreter of object-oriented scripting language
  63 ruby                 2.6          common [d]                            An interpreter of object-oriented scripting language
  64 ruby                 2.7          common [d]                            An interpreter of object-oriented scripting language
  65 rust-toolset         rhel8 [d]    common [d]                            Rust
  66 satellite-5-client   1.0 [d]      common [d], gui                       Red Hat Satellite 5 client packages
  67 scala                2.10 [d]     common [d]                            A hybrid functional/object-oriented language for the JVM
  68 squid                4 [d]        common [d]                            Squid - Optimising Web Delivery
  69 subversion           1.10 [d]     common [d], server                    Apache Subversion
  70 swig                 3.0 [d]      common [d], complete                  Connects C/C++/Objective C to some high-level programming languages
  71 varnish              6 [d]        common [d]                            Varnish HTTP cache
  72 virt                 rhel [d]     common [d]                            Virtualization module
  73 
  74 Hint: [d]efault, [e]nabled, [x]disabled, [i]nstalled

Okay that's a lot.

Change the version by changing the enabled module, hmm.

Enable a module here identity management

   1 [root@ipa2 ~]# dnf module enable idm:DL1
   2 Last metadata expiration check: 2:01:12 ago on Thu 24 Sep 2020 10:28:31 AM CEST.
   3 Dependencies resolved.
   4 ============================================================================================================
   5  Package                  Architecture            Version                    Repository                Size
   6 ============================================================================================================
   7 Enabling module streams:
   8  389-ds                                           1.4
   9  httpd                                            2.4
  10  idm                                              DL1
  11  pki-core                                         10.6
  12  pki-deps                                         10.6
  13 
  14 Transaction Summary
  15 ============================================================================================================
  16 
  17 Is this ok [y/N]: y
  18 Complete!

Trouble Shooting

I got error only in CentOS 8-Stream

   1 dnf module enable idm:DL1
   2 dnf module install idm:DL1/{client,dns,server}
   3 …
   4 [SKIPPED] xmlrpc-c-1.51.0-5.el8.x86_64.rpm: Already downloaded                                                
   5 [SKIPPED] xmlrpc-c-client-1.51.0-5.el8.x86_64.rpm: Already downloaded                                         
   6 Running transaction check
   7 No available modular metadata for modular package '389-ds-base-1.4.3.8-5.module_el8.3.0+473+53682548.x86_64', it cannot be installed on the system
   8 No available modular metadata for modular package '389-ds-base-libs-1.4.3.8-5.module_el8.3.0+473+53682548.x86_64', it cannot be installed on the system
   9 No available modular metadata for modular package 'python3-lib389-1.4.3.8-5.module_el8.3.0+473+53682548.noarch', it cannot be installed on the system
  10 The downloaded packages were saved in cache until the next successful transaction.
  11 You can remove cached packages by executing 'dnf clean packages'.
  12 Error: No available modular metadata for modular package

There were no module artifacts listed

   1 dnf module info 389-ds
   2 Last metadata expiration check: 0:08:07 ago on Wed 23 Sep 2020 06:10:31 PM CEST.
   3 Name             : 389-ds
   4 Stream           : 1.4 [e] [a]
   5 Version          : 8030020200831174107
   6 Context          : 618f7055
   7 Architecture     : x86_64
   8 Profiles         : 
   9 Default profiles : 
  10 Repo             : appstream
  11 Summary          : 389 Directory Server (base)
  12 Description      : 389 Directory Server is an LDAPv3 compliant server.  The base package includes the LDAP server and command line utilities for server administration.
  13 Requires         : platform:[el8]
  14 Artifacts        : 
  15 
  16 Hint: [d]efault, [e]nabled, [x]disabled, [i]nstalled, [a]ctive

According to this thread seemed to be an issue with the module metadata.

Since then the builds seemed to fail on the CentOS CI 8-Stream.

I probably can only wait.

http_proxy dnf

/etc/dnf/dnf.conf

   1 [main]
   2 gpgcheck=1
   3 installonly_limit=3
   4 clean_requirements_on_remove=True
   5 best=False
   6 skip_if_unavailable=True
   7 proxy=http://10.0.0.4:3128

Fedora

Install essential packages

   1 dnf install \
   2         bash-completion byobu btrfs-progs ca-certificates curl \
   3         dmidecode bind-utils dosfstools ethtool git gpm hdparm htop iftop info \
   4         iotop jq lsof man-db mc mlocate net-tools openssl \
   5         parted pigz psmisc pv pwgen rsync screen sqlite strace \
   6         sudo sysstat tmux util-linux-user vim wget zsh