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Installing, managing, and removing user-space components

Red Hat Enterprise Linux 8

Managing content in the BaseOS and AppStream repositories by using the YUM software management tool

Red Hat Customer Content Services

Abstract

Find, install, and utilize content distributed through the BaseOS and AppStream repositories by using the YUM tool. Learn how to work with packages, modules, streams, and profiles.

Making open source more inclusive

Red Hat is committed to replacing problematic language in our code, documentation, and web properties. We are beginning with these four terms: master, slave, blacklist, and whitelist. Because of the enormity of this endeavor, these changes will be implemented gradually over several upcoming releases. For more details, see our CTO Chris Wright’s message.

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Chapter 1. Using AppStream

In the following sections, learn the concepts related to the AppStream repository in Red Hat Enterprise Linux 8:

1.1. Distribution of content in RHEL 8

Red Hat Enterprise Linux 8 content is distributed through the two main repositories: BaseOS and AppStream.

BaseOS
The BaseOS repository contains the core set of the underlying operating system functionality that provides the foundation for all installations. This content is available in the form of RPM packages and is subject to support terms similar to those in earlier releases of Red Hat Enterprise Linux.
AppStream
The AppStream repository contains additional user-space applications, runtime languages, and databases in support of the varied workloads and use cases. Content in AppStream is available in one of two formats - the RPM packages and an extension to the RPM format called modules.
Important

Both BaseOS and AppStream content sets are required for a basic RHEL installation, and are available with all RHEL subscriptions. For installation instructions, see the Performing a standard RHEL 8 installation document.

1.2. Application Streams

Red Hat Enterprise Linux 8 introduces the concept of Application Streams - versions of user-space components. Multiple versions of these components are now delivered and updated more frequently than the core operating system packages. This provides greater flexibility to customize Red Hat Enterprise Linux without impacting the underlying stability of the platform or specific deployments.

Components made available as Application Streams can be packaged as modules or RPM packages, and are delivered through the AppStream repository in Red Hat Enterprise Linux 8. Each Application Stream has a given life cycle, either the same as RHEL 8 or shorter, more suitable to the particular application. Application Streams with a shorter life cycle are listed in the Red Hat Enterprise Linux 8 Application Streams Life Cycle page.

Note

Not all modules are Application Streams. Dependencies of other modules are not considered Application Streams.

Additional Resources

1.3. Packaging methods in RHEL 8

Content in the AppStream repository is packaged in two ways:

  • Individual RPM packages

    Traditional RPM packages available for immediate installation.

  • Modules

    Modules are collections of packages representing a logical unit: an application, a language stack, a database, or a set of tools. These packages are built, tested, and released together.

1.4. Package management using YUM in RHEL 8

The YUM package management tool is now based on the DNF technology and it adds support for the new modular features.

Usage of YUM has not been changed when handling individual RPM packages. For handling the modular content, the yum module command has been added. See Installing RHEL 8 content for additional details.

Where required, the modular functionality automatically selects the appropriate combination of modules and streams to enable installation of logical sets of packages for convenient usage.

Chapter 2. Introduction to modules

Besides individual RPM packages, the AppStream repository contains modules. A module is a set of RPM packages that represent a component and are usually installed together. A typical module contains packages with an application, packages with the application-specific dependency libraries, packages with documentation for the application, and packages with helper utilities.

In the following sections, learn features for organization and handling of content within modules:

2.1. Module streams

Module streams are filters that can be imagined as virtual repositories in the AppStream physical repository. Module streams represent versions of the AppStream components. Each of the streams receives updates independently.

Module streams can be active or inactive. Active streams give the system access to the RPM packages within the particular module stream, allowing installation of the respective component version. Streams are active either if marked as default or if they are explicitly enabled by a user action.

Only one stream of a particular module can be active at a given point in time. Therefore, only one version of a component can be installed on a system. Different versions can be used in separate containers.

Each module can have a default stream. Default streams make it easy to consume RHEL packages the usual way without the need to learn about modules. The default stream is active, unless the whole module has been disabled or another stream of that module enabled.

Important

The default stream does not change throughout the RHEL major release. Always consider each stream’s life cycle. Do not rely on the default stream for instances in which the default stream reaches the End of Life status prior to the end of the RHEL major release.

Certain module streams depend on other module streams. For example, the perl-App-cpanminus, perl-DBD-MySQL, perl-DBD-Pg, perl-DBD-SQLite, perl-DBI, perl-YAML, and freeradius module streams depend on certain perl module streams.

To select a particular stream for a runtime user application or a developer application, consider the following:

  • Required functionality and which component versions support it
  • Compatibility
  • Life cycle length and your update plan

For a list of all available modules and streams, see the Package manifest. For per-component changes, see the Release Notes.

Example 2.1. postgresql module streams

The postgresql module provides the PostgreSQL database versions 9.6, 10, 12, and 13 in the respective streams 9.6, 10, 12, 13, and 15. Stream 10 is the default one. This means that the system attempts to install the postgresql-10.6 package if asked for postgresql.

Always decide which module stream you want to use, and install the version explicitly.

Additional resources

2.2. Module profiles

A profile is a list of recommended packages that are installed together for a particular use case, such as a server, client, development, minimal install, or other. These package lists can contain packages outside the module stream, usually from the BaseOS repository or the dependencies of the stream.

Installing packages by using a profile is a one-time action provided for the user’s convenience. It does not prevent installing or uninstalling any of the packages provided by the module. It is also possible to install packages by using multiple profiles of the same module stream without any further preparatory steps.

Each module stream can have any number of profiles, including none. For any given module stream, some of its profiles can be marked as default and are then used for profile installation actions when no profile is explicitly specified. However, existence of a default profile for a module stream is not required.

Example 2.2. httpd module profiles

The httpd module, which provides the Apache web server, offers the following profiles for installation:

  • common - a hardened production-ready deployment, the default profile.
  • devel - the packages necessary for making modifications to httpd.
  • minimal - the smallest set of packages that provide a running web server.

Chapter 3. Finding RHEL 8 content

In the following sections, learn how to locate and examine content in the AppStream and BaseOS repositories in Red Hat Enterprise Linux 8 by using YUM:

3.1. Searching for a package

To find a package providing a particular application or other content, complete the following steps.

Procedure

  1. Search for a package with a text string, such as application name: 

    $ yum search "text string"

  2. View details about a package: 

    $ yum info package

3.2. Listing available modules and their content

To find out which modules are available and what their details are, complete the following steps.

Procedure

  • To list module streams available to your system, use: 

    $ yum module list

    The output of this command lists module streams with name, stream, profiles, and summary on a separate line.

  • To display details about a module, including a description, a list of all profiles, and a list of all provided packages, use: 

    $ yum module info module-name

  • To list which of these packages are installed by each of module profiles, use: 

    $ yum module info --profile module-name

  • To display the current status of a module, including enabled streams and installed profiles, use: 

    $ yum module list module-name

Additional resources

Example 3.1. Finding out details about a module

The following is an example of how to list available modules in the AppStream repository and how to obtain information about the postgresql module’s contents.

Note

The outputs in this example have been edited for brevity. Actual outputs might contain more information than shown here.

  1. List available modules: 

    $ yum module list
Name         Stream   Profiles    Summary
(...)
postgresql   9.6      client,     PostgreSQL server and client module
                      server [
                      d]
postgresql   10 [d]   client,     PostgreSQL server and client module
                      server [
                      d]
postgresql   12       client,     PostgreSQL server and client module
                      server [
                      d]
postgresql   13       client,     PostgreSQL server and client module
                      server [
                      d]
postgresql   15       client,     PostgreSQL server and client module
                      server [
                      d]
(...)

Hint: [d]efault, [e]nabled, [x]disabled, [i]nstalled

  2. Examine details of the postgresql module: 

    $ yum module info postgresql

...
Name             : postgresql
Stream           : 10 [d][a]
Version          : 8070020221124143148
Context          : bd1311ed
Architecture     : x86_64
Profiles         : client, server [d]
Default profiles : server
Repo             : rhel-AppStream
Summary          : PostgreSQL server and client module
...


Name             : postgresql
Stream           : 12
Version          : 8060020221003080350
Context          : ad008a3a
Architecture     : x86_64
Profiles         : client, server [d]
Default profiles : server
Repo             : rhel-AppStream
Summary          : PostgreSQL server and client module
...

Name             : postgresql
Stream           : 13
Version          : 8070020230227142544
Context          : bd1311ed
Architecture     : x86_64
Profiles         : client, server [d]
Default profiles : server
Repo             : rhel-AppStream
Summary          : PostgreSQL server and client module
...

Name             : postgresql
Stream           : 15
Version          : 8080020230212204728
Context          : fd72936b
Architecture     : x86_64
Profiles         : client, server [d]
Default profiles : server
Repo             : rhel-AppStream
Summary          : PostgreSQL server and client module
...

Name             : postgresql
Stream           : 9.6
Version          : 8040020210602182503
Context          : 522a0ee4
Architecture     : x86_64
Profiles         : client, server [d]
Default profiles : server
Repo             : rhel-AppStream
Summary          : PostgreSQL server and client module
...

Hint: [d]efault, [e]nabled, [x]disabled, [i]nstalled, [a]ctive

    If you do not specify any stream, yum lists all available streams.

  3. Examine profiles available in stream 10 of the postgresql module: 

    $ yum module info --profile postgresql:10
(...)
Name   : postgresql:10:8070020221124143148:bd1311ed:x86_64
client : postgresql
server : postgresql-server

    Note that each of the profiles installs a different set of packages, including their dependencies.

  4. Install the postgresql module by using the default stream 10 and the default profile server: 

    # yum module install postgresql
...
Dependencies resolved.
===================================================================================================================
 Package                  Architecture  Version                                        Repository             Size
===================================================================================================================
Installing group/module packages:
 postgresql-server        x86_64        10.23-1.module+el8.7.0+17280+3a452e1f          rhel-AppStream        5.1 M
Installing dependencies:
 libpq                    x86_64        13.5-1.el8                                     rhel-AppStream        198 k
 postgresql               x86_64        10.23-1.module+el8.7.0+17280+3a452e1f          rhel-AppStream        1.5 M
Installing module profiles:
 postgresql/server
Enabling module streams:
 postgresql                             10

Transaction Summary
===================================================================================================================
Install  3 Packages

Total download size: 6.7 M
Installed size: 26 M
Is this ok [y/N]: y
...

Installed:
  libpq-13.5-1.el8.x86_64
  postgresql-10.23-1.module+el8.7.0+17280+3a452e1f.x86_64
  postgresql-server-10.23-1.module+el8.7.0+17280+3a452e1f.x86_64

Complete!

  5. Inspect the current status of the postgresql module: 

    $ yum module list postgresql
rhel-AppStream
Name                Stream             Profiles                        Summary
postgresql          9.6                client, server [d]              PostgreSQL server and client module
postgresql          10 [d][e]          client, server [d] [i]          PostgreSQL server and client module
postgresql          12                 client, server [d]              PostgreSQL server and client module
postgresql          13                 client, server [d]              PostgreSQL server and client module
postgresql          15                 client, server [d]              PostgreSQL server and client module

Hint: [d]efault, [e]nabled, [x]disabled, [i]nstalled

    The output shows that the default stream 10 is enabled and its profile server is installed.

3.3. Commands for listing content

The following are the commonly used commands for finding content and its details in Red Hat Enterprise Linux 8.

CommandDescription

yum list available

List available packages.

yum repoquery package

Search available YUM repositories for a selected package.

yum search "text string"

Search for a package by using arbitrary text string.

yum info package

Display details for a package.

yum module provides package

Display which modules provide a package.

If the package is available outside any modules, the output of this command is empty.

yum module list

List available modules.

yum module info module-name

Display details of a module.

yum module info --profile module-name

List packages installed by profiles of a module by using the default stream.

yum module info --profile module-name:stream

Display packages installed by profiles of a module by using a specified stream.

yum module list module-name

Display the current status of a module.

Chapter 4. Installing RHEL 8 content

In the following sections, learn how to install content in Red Hat Enterprise Linux 8:

4.1. Installing a package

To install a package, complete the following steps.

Procedure

  • Install a package: 

    # yum install package

    Replace package with the name of the package.

    • If the package is not provided by any module stream, this procedure is identical to the procedure used on earlier versions of Red Hat Enterprise Linux.
    • If the package is provided by an module stream that is enabled, the package is installed without any further manipulation.

    • If the package is provided by a module stream marked as default, yum automatically enables that module stream before installing this package.

      Important

      It is recommended to always select a specific module stream for installation instead of relying on the default stream. Certain default module streams reach the End of Life status prior to the end of the RHEL major release. Always consider each stream’s lifecycle.

  • If the package is provided by a module stream that is not active (neither of the above cases), it is not recognized until you manually enable the respective module stream.

Additional resources

4.2. Selecting a stream before installation of packages

It is recommended to always select a specific module stream for installation. Always consider each stream’s life cycle.

Important

Certain default module streams reach the End of Life status prior to the end of the RHEL major release.

To install packages from a non-default stream, enable the stream first.

Prerequisites

Procedure

  • Enable the module stream: 

    # yum module enable module-name:stream

    Replace module-name and stream with names of the module and stream.

    yum asks for confirmation and the stream is enabled and active.

    Note

    If another stream of the module was previously active because it was default, it is no longer active.

Additional resources

4.3. Installing modular content

To install modular content provided by a module stream or a profile, complete the following steps.

Prerequisites

Procedure

  • To install a selected module stream, use: 

    # yum module install module-name:stream

    By running this command, you automatically enable selected stream. Note that if a default profile is defined for the stream, this profile is automatically installed.

    Important

    Always consider the module stream’s life cycle.

  • To install a selected profile of the module stream, use: 

    # yum module install module-name:stream/profile

    By running this command, you enable the stream and install the recommended set of packages for a given stream (version) and profile (purpose) of the module.

Additional resources

Example 4.1. Installing a non-default stream of an application

The following is an example of how to install an application from a non-default stream (version), namely, the PostgreSQL server (the postgresql-server package) in version 13. The default stream provides version 10.

Procedure

  1. List modules that provide the postgresql-server package to see which streams are available: 

    $ yum module list postgresql
Name        Stream  Profiles            Summary
postgresql  9.6     client, server [d]  PostgreSQL server and client module
postgresql  10 [d]  client, server [d]  PostgreSQL server and client module
postgresql  12      client, server [d]  PostgreSQL server and client module
postgresql  13      client, server [d]  PostgreSQL server and client module
postgresql  15      client, server [d]  PostgreSQL server and client module

Hint: [d]efault, [e]nabled, [x]disabled, [i]nstalled

    The output shows that the postgresql module is available with streams 9.6, 10, 12, 13, and 15. The default stream is 10.

  2. Install the packages provided by the postgresql module in stream 13: 

    # yum module install postgresql:13
...
Dependencies resolved.
===================================================================================================================
 Package                  Architecture  Version                                        Repository             Size
===================================================================================================================
Installing group/module packages:
 postgresql-server        x86_64        13.10-1.module+el8.7.0+18279+1ca8cf12          rhel-AppStream        5.6 M
Installing dependencies:
 libicu                   x86_64        60.3-2.el8_1                                   rhel                  8.8 M
 libpq                    x86_64        13.5-1.el8                                     rhel-AppStream        198 k
 postgresql               x86_64        13.10-1.module+el8.7.0+18279+1ca8cf12          rhel-AppStream        1.5 M
Installing module profiles:
 postgresql/server
Enabling module streams:
 postgresql                             13

Transaction Summary
===================================================================================================================
Install  4 Packages

Total download size: 16 M
Installed size: 61 M
Is this ok [y/N]: y

...

Installed:
  libicu-60.3-2.el8_1.x86_64
  libpq-13.5-1.el8.x86_64
  postgresql-13.10-1.module+el8.7.0+18279+1ca8cf12.x86_64
  postgresql-server-13.10-1.module+el8.7.0+18279+1ca8cf12.x86_64

Complete!

    Because the installation profile was not specified, the default profile server was used.

  3. Verify the installed version of PostgreSQL: 

    $ postgres --version
postgres (PostgreSQL) 13.10

4.4. Running installed content

New commands are usually enabled after you install content from RHEL 8 repositories. If the commands originated from RPM packages that were enabled by a module, the experience of using these command should be no different.

Procedure

  • To run the new commands, enter them directly: 

    $ command

    Replace command with the name of the command you want to run.

Note

In RHEL 8, GCC Toolset is packaged as a Software Collection. To run a command from a component packaged as a Software Collection, use: 

$ scl enable collection 'command'

Replace collection with the name of the Software Collection.

For more information, see Using GCC Toolset.

4.5. Commands for installing RHEL 8 content

The following are the commonly used commands for installing Red Hat Enterprise Linux 8 content.

CommandDescription

yum install package

Install a package.

If the package is provided by a module stream, yum resolves the required module stream and enables it automatically while installing this package. This also happens recursively for all package dependencies. If more module streams satisfy the requirement, the default ones are used.

yum module enable module-name:stream

Enable a module by using a specific stream.

Always consider the module stream’s life cycle.

yum module install module-name:stream

yum install @module-name:stream

Install a module by using a specific stream and default profiles

yum module install module-name:stream/profile

yum install @module-name:stream/profile

Install a module by using a specific stream and profile.

4.6. Additional resources

Chapter 5. Removing RHEL 8 content

In the following sections, learn how to remove content in Red Hat Enterprise Linux 8:

5.1. Removing installed packages

To remove a package installed on your system, complete the following steps.

Procedure

  • To remove a specific package, use: 

    # yum remove package-name

    Replace package-name with the name of the package you want to remove.

    Note

    The yum command removes a package together with any other dependent packages.

5.2. Removing installed modular content

When removing installed modular content, you can remove packages either from a selected profile or from the whole stream.

Important

YUM removes all packages with a name corresponding to the packages installed with a profile or a stream, including their dependent packages. Always check the list of packages to be removed before you proceed, especially if you have enabled custom repositories on your system.

5.2.1. Removing all packages from a module stream

When you remove packages installed with a module stream, yum removes all packages with a name corresponding to the packages installed by the stream. This includes packages' dependencies, with the exception of packages required by other modules.

Prerequisites

  • The module stream has been enabled and at least some packages from the stream have been installed.
  • You understand modular dependency resolution.

Procedure

  1. Remove all packages from a selected stream: 

    # yum module remove --all module-name:stream

    Replace module-name and stream with the module and stream you want to uninstall.

  2. Check the list of packages under Removing: and Removing unused dependencies: before you proceed with the removal transaction.
  3. Optionally, reset or disable the stream.

If you want to remove only packages from a selected profile, follow instructions in Removing packages from an installed profile.

Example 5.1. Removing packages from the whole stream

The following is an example of how to remove all packages from the php:7.3 module stream.

Procedure

  1. Install the php:7.3 module stream, including all available profiles: 

    # yum module install php:7.3/*
Updating Subscription Management repositories.
Last metadata expiration check: 0:20:19 ago on Tue Mar  3 11:32:05 2020.
Dependencies resolved.
=========================================================================
 Package          Arch   Version                              Repository                        Size
=========================================================================
Installing group/module packages:
 libzip           x86_64 1.5.2-1.module+el8.1.0+3189+a1bff096 rhel-8-for-x86_64-appstream-rpms  63 k
 php-cli          x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6 rhel-8-for-x86_64-appstream-rpms 3.0 M
 php-common       x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6 rhel-8-for-x86_64-appstream-rpms 663 k
 php-devel        x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6 rhel-8-for-x86_64-appstream-rpms 735 k
 php-fpm          x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6 rhel-8-for-x86_64-appstream-rpms 1.6 M
 php-json         x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6 rhel-8-for-x86_64-appstream-rpms  73 k
 php-mbstring     x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6 rhel-8-for-x86_64-appstream-rpms 610 k
 php-pear         noarch 1:1.10.9-1.module+el8.1.0+3189+a1bff096
                                                              rhel-8-for-x86_64-appstream-rpms 359 k
 php-pecl-zip     x86_64 1.15.4-1.module+el8.1.0+3189+a1bff096
                                                              rhel-8-for-x86_64-appstream-rpms  51 k
 php-process      x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6 rhel-8-for-x86_64-appstream-rpms  84 k
 php-xml          x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6 rhel-8-for-x86_64-appstream-rpms 188 k
Installing dependencies:
 autoconf         noarch 2.69-27.el8                          rhel-8-for-x86_64-appstream-rpms 710 k
...
Installing weak dependencies:
 perl-IO-Socket-IP
                  noarch 0.39-5.el8                           rhel-8-for-x86_64-appstream-rpms  47 k
...
Installing module profiles:
 php/common
 php/devel
 php/minimal
Enabling module streams:
 httpd                   2.4
 nginx                   1.14
 php                     7.3

Transaction Summary
=========================================================================
Install  73 Packages

Total download size: 76 M
Installed size: 220 M
Is this ok [y/N]: y

  2. Inspect the php module: 

    $ yum module info php
...
Name             : php
Stream           : 7.3 [e] [a]
Version          : 8020020200715124551
Context          : ceb1cf90
Architecture     : x86_64
Profiles         : common [d] [i], devel [i], minimal [i]
Default profiles : common
...
Hint: [d]efault, [e]nabled, [x]disabled, [i]nstalled, [a]ctive

  3. Remove all packages from the php:7.3 module stream: 

    # yum module remove --all php:7.3
Updating Subscription Management repositories.
Last metadata expiration check: 0:21:26 ago on Tue Mar  3 11:32:05 2020.
Dependencies resolved.
=========================================================================
 Package                Arch   Version                       Repository                         Size
=========================================================================
Removing:
 libzip                 x86_64 1.5.2-1.module+el8.1.0+3189+a1bff096
                                                             @rhel-8-for-x86_64-appstream-rpms 313 k
 php-cli                x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6
                                                             @rhel-8-for-x86_64-appstream-rpms  11 M
 php-common             x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6
                                                             @rhel-8-for-x86_64-appstream-rpms 6.5 M
 php-devel              x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6
                                                             @rhel-8-for-x86_64-appstream-rpms 5.3 M
 php-fpm                x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6
                                                             @rhel-8-for-x86_64-appstream-rpms 5.6 M
 php-json               x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6
                                                             @rhel-8-for-x86_64-appstream-rpms  53 k
 php-mbstring           x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6
                                                             @rhel-8-for-x86_64-appstream-rpms 1.9 M
 php-pear               noarch 1:1.10.9-1.module+el8.1.0+3189+a1bff096
                                                             @rhel-8-for-x86_64-appstream-rpms 2.1 M
 php-pecl-zip           x86_64 1.15.4-1.module+el8.1.0+3189+a1bff096
                                                             @rhel-8-for-x86_64-appstream-rpms 119 k
 php-process            x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6
                                                             @rhel-8-for-x86_64-appstream-rpms 117 k
 php-xml                x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6
                                                             @rhel-8-for-x86_64-appstream-rpms 557 k
Removing unused dependencies:
 autoconf               noarch 2.69-27.el8                   @rhel-8-for-x86_64-appstream-rpms 2.2 M
...
Disabling module profiles:
 php/common
 php/devel
 php/minimal

Transaction Summary
=========================================================================
Remove  73 Packages

Freed space: 220 M
Is this ok [y/N]: y

  4. Inspect the php module after the removal: 

    $ yum module info php
...
Name             : php
Stream           : 7.3 [e] [a]
Version          : 8020020200715124551
Context          : ceb1cf90
Architecture     : x86_64
Profiles         : common [d], devel, minimal
Default profiles : common
...
Hint: [d]efault, [e]nabled, [x]disabled, [i]nstalled, [a]ctive

The 7.3 stream of the php module is currently enabled but no packages from this streams are installed.

5.2.2. Removing packages from an installed profile

When you remove packages installed with a profile, yum removes all packages with a name corresponding to the packages installed by the profile. This includes package dependencies, with the exception of packages required by a different profile.

Prerequisites

  • The selected profile has been installed by using the yum module install module-name:stream/profile command or as a default profile by using the yum install module-name:stream command.
  • You understand modular dependency resolution.

Procedure

  1. Uninstall packages belonging to the selected profile: 

    # yum module remove module-name:stream/profile

    Replace module-name, stream, and profile with the module, stream, and profile you want to uninstall.

    Alternatively, uninstall packages from all installed profiles within a stream: 

    # yum module remove module-name:stream

    These operations will not remove packages from the stream that do not belong to any of the profiles.

  2. Check the list of packages under Removing: and Removing unused dependencies: before you proceed with the removal transaction.

To remove all packages from a selected stream, follow instructions in Removing all packages from a module stream.

Example 5.2. Removing packages from a selected profile

The following is an example of how to remove packages and their dependencies that belong to the devel profile of the php:7.3 module stream.

Note

The outputs in this example have been edited for brevity. Actual outputs might contain more information than shown here.

Procedure

  1. Install the php:7.3 module stream, including all available profiles: 

    # yum module install php:7.3/*
Updating Subscription Management repositories.
Last metadata expiration check: 0:08:41 ago on Tue Mar  3 11:32:05 2020.
Dependencies resolved.
=========================================================================
 Package          Arch   Version                              Repository                        Size
=========================================================================
Installing group/module packages:
 libzip           x86_64 1.5.2-1.module+el8.1.0+3189+a1bff096 rhel-8-for-x86_64-appstream-rpms  63 k
 php-cli          x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6 rhel-8-for-x86_64-appstream-rpms 3.0 M
 php-common       x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6 rhel-8-for-x86_64-appstream-rpms 663 k
 php-devel        x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6 rhel-8-for-x86_64-appstream-rpms 735 k
 php-fpm          x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6 rhel-8-for-x86_64-appstream-rpms 1.6 M
 php-json         x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6 rhel-8-for-x86_64-appstream-rpms  73 k
 php-mbstring     x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6 rhel-8-for-x86_64-appstream-rpms 610 k
 php-pear         noarch 1:1.10.9-1.module+el8.1.0+3189+a1bff096
                                                              rhel-8-for-x86_64-appstream-rpms 359 k
 php-pecl-zip     x86_64 1.15.4-1.module+el8.1.0+3189+a1bff096
                                                              rhel-8-for-x86_64-appstream-rpms  51 k
 php-process      x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6 rhel-8-for-x86_64-appstream-rpms  84 k
 php-xml          x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6 rhel-8-for-x86_64-appstream-rpms 188 k
Installing dependencies:
 autoconf         noarch 2.69-27.el8                          rhel-8-for-x86_64-appstream-rpms 710 k
...
Installing weak dependencies:
 perl-IO-Socket-IP
                  noarch 0.39-5.el8                           rhel-8-for-x86_64-appstream-rpms  47 k
...
Installing module profiles:
 php/common
 php/devel
 php/minimal
Enabling module streams:
 httpd                   2.4
 nginx                   1.14
 php                     7.3

Transaction Summary
=========================================================================
Install  73 Packages

Total download size: 76 M
Installed size: 220 M
Is this ok [y/N]: y

  2. Inspect the installed profiles: 

    $ yum module info php
...
Name             : php
Stream           : 7.3 [e] [a]
Version          : 8020020200715124551
Context          : ceb1cf90
Architecture     : x86_64
Profiles         : common [d] [i], devel [i], minimal [i]
Default profiles : common
Repo             : rhel-AppStream
....
Hint: [d]efault, [e]nabled, [x]disabled, [i]nstalled, [a]ctive

    All profiles are installed as indicated in the output.

  3. Remove packages from the devel profile: 

    # yum module remove php:7.3/devel
Updating Subscription Management repositories.
Last metadata expiration check: 0:09:40 ago on Tue Mar  3 11:32:05 2020.
Dependencies resolved.
=========================================================================
 Package                Arch   Version                       Repository                         Size
=========================================================================
Removing:
 libzip                 x86_64 1.5.2-1.module+el8.1.0+3189+a1bff096
                                                             @rhel-8-for-x86_64-appstream-rpms 313 k
 php-devel              x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6
                                                             @rhel-8-for-x86_64-appstream-rpms 5.3 M
 php-pear               noarch 1:1.10.9-1.module+el8.1.0+3189+a1bff096
                                                             @rhel-8-for-x86_64-appstream-rpms 2.1 M
 php-pecl-zip           x86_64 1.15.4-1.module+el8.1.0+3189+a1bff096
                                                             @rhel-8-for-x86_64-appstream-rpms 119 k
 php-process            x86_64 7.3.5-5.module+el8.1.0+4560+e0eee7d6
                                                             @rhel-8-for-x86_64-appstream-rpms 117 k
Removing unused dependencies:
 autoconf               noarch 2.69-27.el8                   @rhel-8-for-x86_64-appstream-rpms 2.2 M
...
Disabling module profiles:
 php/devel

Transaction Summary
=========================================================================
Remove  64 Packages

Freed space: 193 M
Is this ok [y/N]: y

  4. Inspect the installed profiles after the removal: 

    $ yum module info php
...
Name             : php
Stream           : 7.3 [e] [a]
Version          : 8020020200715124551
Context          : ceb1cf90
Architecture     : x86_64
Profiles         : common [d] [i], devel, minimal [i]
Default profiles : common
Repo             : rhel-AppStream
...
Hint: [d]efault, [e]nabled, [x]disabled, [i]nstalled, [a]ctive

    All profiles except devel are currently installed.

5.3. Commands for removing content

The following are the commonly used commands for removing content in Red Hat Enterprise Linux 8.

CommandDescription

yum remove package

Remove a package.

yum module remove module-name:stream/profile

Remove packages from an installed profile.

yum module remove --all module-name:stream

Remove all packages from an active stream.

yum module reset module-name

Reset a module to the initial state.

yum module disable module-name

Disable a module and all its streams.

Chapter 6. Managing versions of Application Stream content

Content in the AppStream repository can be available in multiple versions, corresponding to module streams.

In the following sections, learn operations you must perform when changing existing enabled module streams:

6.1. Modular dependencies and stream changes

Traditionally, packages providing content depend on further packages, and usually specify the desired dependency versions. For packages contained in modules, this mechanism applies as well, but the grouping of packages and their particular versions into modules and streams provides further constraints. Additionally, module streams can declare dependencies on streams of other modules, independent of the packages contained and provided by them.

After any operations with packages or modules, the whole dependency tree of all underlying installed packages must satisfy all the conditions the packages declare. Additionally, all module stream dependencies must be satisfied.

As a result:

  • Enabling a module stream can require enabling streams of further modules.
  • Installing a module stream profile or installing packages from a stream can require enabling streams of further modules and installing further packages.
  • Disabling a stream of a module can require disabling other module streams. No packages will be removed automatically.
  • Removing a package can require removing further packages. If these packages were provided by modules, the module streams remain enabled in preparation for further installation, even if there are no packages installed from these streams anymore. This mirrors the behavior of an unused YUM repository.
Important

You cannot enable a stream of a module when another stream of the same module is already enabled. To switch streams, follow the procedure in Switching to a later stream. Alternatively, reset the module, and then enable the new stream.

Removing all packages installed from a stream before switching to a different stream prevents the system from reaching states where packages could be installed with no repository or stream that provides them.

Technically, resetting module does not automatically change any installed packages. Removing the packages provided by the previous stream and any packages that depend on them is an explicit manual operation.

6.2. Interaction of modular and non-modular dependencies

Modular dependencies are an additional layer on top of regular RPM dependencies. Modular dependencies behave similarly to hypothetical dependencies between repositories. This means that installing different packages requires not only resolution of the RPM dependencies, but also the modular dependencies must be resolved beforehand.

The system always retains the module and stream choices, unless explicitly instructed to change them. A modular package receives updates contained in the currently enabled stream of the module that provides this package, but does not upgrade to a version contained in a different stream.

6.3. Resetting module streams

Resetting a module is an action that returns all of its streams to their initial state - neither enabled nor disabled. If the module has a default stream, this stream becomes active as a result of resetting the module.

Procedure

  • Reset the module state: 

    # yum module reset module-name

    Replace module-name with the name of the module that you want to reset.

    The module is returned to the initial state. Information about an enabled stream and installed profiles is erased but no installed content is removed.

6.4. Disabling all streams of a module

Modules that have a default stream always have one stream active. In situations where the content from all the module streams must not be accessible, it is possible to disable the whole module.

Prerequisites

Procedure

  • Disable the module: 

    # yum module disable module-name

    Replace module-name with the name of the module that you want to disable.

    The yum command asks for confirmation and then disables the module with all its streams. All of the module streams become inactive. No installed content is removed.

6.5. Switching to a later stream

When you switch to a later module stream, all packages from the module are replaced with their later versions.

Important

This procedure is feasible only under the conditions described in the Prerequisites section.

Prerequisites

  • The system is fully updated.
  • No packages installed on the system are newer than the packages available in the repository.

Procedure

  1. Determine if your system is prepared for switching to a later stream: 

    # yum distro-sync

    This command must finish with the message Nothing to do. Complete! If it instead proposes changes and asks for confirmation, carefully review these changes and consider whether you want to proceed. Run the yum distro-sync command repeatedly if necessary. Alternatively, you can refuse the suggested changes and manually modify your system to a state where the command returns Nothing to do. Complete!

    Note

    By checking the yum distro-sync result before switching the streams, you prevent making changes to the system that are unrelated to the stream switching because the same command is required as the last step of this procedure.

  2. Change the active stream to the later one: 

    # yum module reset module-name
# yum module enable module-name:new-stream

  3. Synchronize installed packages to perform the change between streams: 

    # yum distro-sync

    If this action suggests changes to content outside the streams, review them carefully.

    Note
    • If certain installed packages depend on the earlier stream, and there is no compatible version in the later stream, yum reports a dependency conflict. In this case, use the --allowerasing option to remove such packages because they cannot be installed together with the later stream due to missing dependencies.
    • When switching Perl modules, you must always use the --allowerasing option because certain packages in the base RHEL 8 installation depend on Perl 5.26.
    • Binary extensions (typically written in C or C++) for interpreted languages need to be reinstalled after the new stream is enabled; for example, certain packages installed by the gem command from the ruby module, the npm command from the nodejs module, the cpan command from the perl module, or the pecl command from the php module. For more information, see How to switch Ruby streams in RHEL 8.

Alternatively, remove all the module’s content installed from the current stream, reset the module, and install the new stream.

6.6. Overriding module default streams

By default, the YUM utility uses the module default streams defined in the repository that contains the modules. You can override the default stream in the /etc/dnf/modules.defaults.d/ directory.

Important

Always consider the module stream’s life cycle.

Prerequisites

Procedure

  1. Create a YAML configuration file in the /etc/dnf/modules.defaults.d/ drop-in directory. 

    ---
document: modulemd-defaults
version: 1
data:
  module: postgresql
  stream: "10"
  profiles:
    10: [server]
    12: [server]
    13: [server]
    15: [server]
    9.6: [server]
…​

    The preceding output represents the default definition present for the postgresql module at the time of this writing.

    Example 6.1. Example postgresql module with original defaults

    The following is an example of how to configure the stream 13 of the postgresql module as the default stream.

    1. Examine the postgresql module: 

      # yum module list postgresql
(…​)
Red Hat Enterprise Linux 8 for x86_64 - AppStream (RPMs)
Name             Stream       Profiles                Summary
postgresql       9.6          client, server [d]      PostgreSQL server and client module
postgresql       10 [d]       client, server [d]      PostgreSQL server and client module
postgresql       12           client, server [d]      PostgreSQL server and client module
postgresql       13           client, server [d]      PostgreSQL server and client module
postgresql       15           client, server [d]      PostgreSQL server and client module
…​
Hint: [d]efault, [e]nabled, [x]disabled, [i]nstalled

    2. To set the default stream to 13, implement the following YAML file configuration in the /etc/dnf/modules.defaults.d/postgresql.yaml file. 

      ---
document: modulemd-defaults
version: 1
data:
  module: postgresql
  stream: "13"
  profiles:
    10: [server]
    12: [server]
    13: [server]
    15: [server]
    9.6: [server]
…​

    3. Examine the postgresql module again: 

      # yum module list postgresql
(…​)
Red Hat Enterprise Linux 8 for x86_64 - AppStream (RPMs)
Name             Stream       Profiles                Summary
postgresql       9.6          client, server [d]      PostgreSQL server and client module
postgresql       10           client, server [d]      PostgreSQL server and client module
postgresql       12           client, server [d]      PostgreSQL server and client module
postgresql       13 [d]       client, server [d]      PostgreSQL server and client module
postgresql       15           client, server [d]      PostgreSQL server and client module
…​
Hint: [d]efault, [e]nabled, [x]disabled, [i]nstalled

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