6.f Work with package module streams...
Definition...
RHEL 8 content is distributed through two main repositories: BaseOS and AppStream.
BaseOS
Content in the BaseOS repository is intended to provide the core set of the underlying OS functionality that provides the foundation for all installations. This content is available in the RPM format and is subject to support terms similar to those in previous releases of Red Hat Enterprise Linux.
AppStream
Content in the AppStream repository includes 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 familiar RPM format and an extension to the RPM format called modules.
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 AppStream component has a given life cycle.
Modules...
Modules allow you to install a specific version and/or type of an application in your system. For example, for 'postgresql' you can choose to install from multiple versions (stream), and client/server type (profile).
# dnf module list postgresql
Last metadata expiration check: 0:20:44 ago on Sat 14 Mar 2020 08:59:58 PM UTC.
CentOS-8 - AppStream
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 PostgreSQL server and client module
Hint: [d]efault, [e]nabled, [x]disabled, [i]nstalled
For httpd on Centos8, currently only one stream (version) is available, and profiles are the package type (common, minimal, development)
# dnf module list httpd
Last metadata expiration check: 0:21:46 ago on Sat 14 Mar 2020 08:59:58 PM UTC.
CentOS-8 - AppStream
Name Stream Profiles Summary
httpd 2.4 [d][e] common [d], devel, minimal Apache HTTP Server
Hint: [d]efault, [e]nabled, [x]disabled, [i]nstalled
Working with Modules...
Getting Information on Modules...
Listing all modules
# dnf module list
Listing module summary for one module
# dnf module list [module]
# dnf module list httpd
Last metadata expiration check: 0:21:46 ago on Sat 14 Mar 2020 08:59:58 PM UTC.
CentOS-8 - AppStream
Name Stream Profiles Summary
httpd 2.4 [d][e] common [d], devel, minimal Apache HTTP Server
Listing info on a module
# dnf module info [module]
# dnf module info httpd
Last metadata expiration check: 0:35:45 ago on Sat 14 Mar 2020 08:59:58 PM UTC.
Name : httpd
Stream : 2.4 [d][e][a]
Version : 8010020191223202455
Context : cdc1202b
Architecture : x86_64
Profiles : common [d], devel, minimal
Default profiles : common
Repo : AppStream
Summary : Apache HTTP Server
Description : Apache httpd is a powerful, efficient, and extensible HTTP server.
Artifacts : httpd-0:2.4.37-16.module_el8.1.0+256+ae790463.src
: httpd-0:2.4.37-16.module_el8.1.0+256+ae790463.x86_64
: httpd-debuginfo-0:2.4.37-16.module_el8.1.0+256+ae790463.x86_64
: httpd-debugsource-0:2.4.37-16.module_el8.1.0+256+ae790463.x86_64
: httpd-devel-0:2.4.37-16.module_el8.1.0+256+ae790463.x86_64
: httpd-filesystem-0:2.4.37-16.module_el8.1.0+256+ae790463.noarch
: httpd-manual-0:2.4.37-16.module_el8.1.0+256+ae790463.noarch
: httpd-tools-0:2.4.37-16.module_el8.1.0+256+ae790463.x86_64
: httpd-tools-debuginfo-0:2.4.37-16.module_el8.1.0+256+ae790463.x86_64
: mod_http2-0:1.11.3-3.module_el8.1.0+213+acce2796.src
: mod_http2-0:1.11.3-3.module_el8.1.0+213+acce2796.x86_64
: mod_http2-debuginfo-0:1.11.3-3.module_el8.1.0+213+acce2796.x86_64
: mod_http2-debugsource-0:1.11.3-3.module_el8.1.0+213+acce2796.x86_64
: mod_ldap-0:2.4.37-16.module_el8.1.0+256+ae790463.x86_64
: mod_ldap-debuginfo-0:2.4.37-16.module_el8.1.0+256+ae790463.x86_64
: mod_md-0:2.4.37-16.module_el8.1.0+256+ae790463.x86_64
: mod_md-debuginfo-0:2.4.37-16.module_el8.1.0+256+ae790463.x86_64
: mod_proxy_html-1:2.4.37-16.module_el8.1.0+256+ae790463.x86_64
: mod_proxy_html-debuginfo-1:2.4.37-16.module_el8.1.0+256+ae790463.x86_64
: mod_session-0:2.4.37-16.module_el8.1.0+256+ae790463.x86_64
: mod_session-debuginfo-0:2.4.37-16.module_el8.1.0+256+ae790463.x86_64
: mod_ssl-1:2.4.37-16.module_el8.1.0+256+ae790463.x86_64
: mod_ssl-debuginfo-1:2.4.37-16.module_el8.1.0+256+ae790463.x86_64
Listing profiles
# dnf module info --profile [module]
# dnf module info --profile httpd
Last metadata expiration check: 0:36:28 ago on Sat 14 Mar 2020 08:59:58 PM UTC.
Name : httpd:2.4:8010020191223202455:cdc1202b:x86_64
common : httpd
: httpd-filesystem
: httpd-tools
: mod_http2
: mod_ssl
devel : httpd
: httpd-devel
: httpd-filesystem
: httpd-tools
minimal : httpd
You can also filter the information with '[module_name]:[stream]'
# dnf module info --profile php:7.3
Changing Stream and Profile...
⚠️ WARNING: Switching module streams will not alter installed packages. You will need to remove a package, reset the module stream and then install the new module stream for the package.
Via 'module enable/disable'...
Enable the stream for 'postgresql' v9.6
# dnf module enable postgresql:9.6
Enable the httpd devel profile
# dnf module enable --profile httpd:2.4/devel
Last metadata expiration check: 0:47:51 ago on Sat 14 Mar 2020 08:59:58 PM UTC.
Ignoring unnecessary profile: 'httpd/devel'
Dependencies resolved.
Nothing to do.
Complete!
Then install the package
# yum install postgresql httpd
To change a module stream again, you will need to run yum module reset [module name], and then enable the new module.
# yum module enable postgresql:10
Last metadata expiration check: 0:06:07 ago on Sat 14 Mar 2020 09:57:50 PM UTC.
Dependencies resolved.
The operation would result in switching of module 'postgresql' stream '9.6' to stream '10'
Error: It is not possible to switch enabled streams of a module.
It is recommended to remove all installed content from the module, and reset the module using 'dnf module reset <module_name>' command. After you reset the module, you can install the other stream.
# yum module reset postgresql
Last metadata expiration check: 0:06:15 ago on Sat 14 Mar 2020 09:57:50 PM UTC.
Dependencies resolved.
=================================================================================================
Package Architecture Version Repository Size
=================================================================================================
Resetting modules:
postgresql
Transaction Summary
=================================================================================================
Is this ok [y/N]: y
Complete!
Directly with dnf module install...
Here we see that the stream is setup to use postgresql 10
# dnf module list postgresql
Updating Subscription Management repositories.
Last metadata expiration check: 1:21:21 ago on Tue 24 Nov 2020 01:34:58 PM EST.
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
Hint: [d]efault, [e]nabled, [x]disabled, [i]nstalled
Install another version with 'dnf module install'
# dnf module install postgresql:9.6
Updating Subscription Management repositories.
Last metadata expiration check: 1:22:00 ago on Tue 24 Nov 2020 01:34:58 PM EST.
Dependencies resolved.
=========================================================================================================
Package Arch Version Repository Size
=========================================================================================================
Installing group/module packages:
postgresql-server x86_64 9.6.10-1.module+el8+2470+d1bafa0e rhel-8-for-x86_64-appstream-rpms 5.0 M
Installing dependencies:
libpq x86_64 12.4-1.el8_2 rhel-8-for-x86_64-appstream-rpms 195 k
postgresql x86_64 9.6.10-1.module+el8+2470+d1bafa0e rhel-8-for-x86_64-appstream-rpms 1.4 M
Installing module profiles:
postgresql/server
Enabling module streams:
postgresql 9.6
Transaction Summary
=========================================================================================================
Install 3 Packages
Total download size: 6.6 M
Installed size: 27 M
Is this ok [y/N]: y
Downloading Packages:
(1/3): libpq-12.4-1.el8_2.x86_64.rpm 502 kB/s | 195 kB 00:00
(2/3): postgresql-9.6.10-1.module+el8+2470+d1bafa0e.x86_64.rpm 1.0 MB/s | 1.4 MB 00:01
(3/3): postgresql-server-9.6.10-1.module+el8+2470+d1bafa0e.x86_64.rpm 2.5 MB/s | 5.0 MB 00:02
---------------------------------------------------------------------------------------------------------
Total 3.2 MB/s | 6.6 MB 00:02
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing : 1/1
Installing : libpq-12.4-1.el8_2.x86_64 1/3
Installing : postgresql-9.6.10-1.module+el8+2470+d1bafa0e.x86_64 2/3
Running scriptlet: postgresql-server-9.6.10-1.module+el8+2470+d1bafa0e.x86_64 3/3
Installing : postgresql-server-9.6.10-1.module+el8+2470+d1bafa0e.x86_64 3/3
Running scriptlet: postgresql-server-9.6.10-1.module+el8+2470+d1bafa0e.x86_64 3/3
Verifying : postgresql-9.6.10-1.module+el8+2470+d1bafa0e.x86_64 1/3
Verifying : postgresql-server-9.6.10-1.module+el8+2470+d1bafa0e.x86_64 2/3
Verifying : libpq-12.4-1.el8_2.x86_64 3/3
Installed products updated.
Installed:
libpq-12.4-1.el8_2.x86_64
postgresql-9.6.10-1.module+el8+2470+d1bafa0e.x86_64
postgresql-server-9.6.10-1.module+el8+2470+d1bafa0e.x86_64
Complete!
You can see now that the stream for 9.6 is enabled
# dnf module list postgresql
Updating Subscription Management repositories.
Last metadata expiration check: 1:25:13 ago on Tue 24 Nov 2020 01:34:58 PM EST.
Red Hat Enterprise Linux 8 for x86_64 - AppStream (RPMs)
Name Stream Profiles Summary
postgresql 9.6 [e] client, server [d] [i] 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
Hint: [d]efault, [e]nabled, [x]disabled, [i]nstalled
If you try to install another stream it will error out
# dnf module install postgresql:10
Updating Subscription Management repositories.
Last metadata expiration check: 1:25:55 ago on Tue 24 Nov 2020 01:34:58 PM EST.
Dependencies resolved.
The operation would result in switching of module 'postgresql' stream '9.6' to stream '10'
Error: It is not possible to switch enabled streams of a module.
It is recommended to remove all installed content from the module, and reset the module using 'dnf module reset <module_name>' command. After you reset the module, you can install the other stream.
Uninstall the package
# dnf module remove -y postgresql
Updating Subscription Management repositories.
Last metadata expiration check: 1:31:35 ago on Tue 24 Nov 2020 01:34:58 PM EST.
Dependencies resolved.
=========================================================================================================
Package Arch Version Repository Size
=========================================================================================================
Removing:
postgresql-server x86_64 9.6.10-1.module+el8+2470+d1bafa0e @rhel-8-for-x86_64-appstream-rpms 21 M
Removing unused dependencies:
libpq x86_64 12.4-1.el8_2 @rhel-8-for-x86_64-appstream-rpms 719 k
postgresql x86_64 9.6.10-1.module+el8+2470+d1bafa0e @rhel-8-for-x86_64-appstream-rpms 5.2 M
Disabling module profiles:
postgresql/server
Transaction Summary
=========================================================================================================
Remove 3 Packages
Freed space: 27 M
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing : 1/1
Running scriptlet: postgresql-server-9.6.10-1.module+el8+2470+d1bafa0e.x86_64 1/1
Running scriptlet: postgresql-server-9.6.10-1.module+el8+2470+d1bafa0e.x86_64 1/3
Erasing : postgresql-server-9.6.10-1.module+el8+2470+d1bafa0e.x86_64 1/3
Running scriptlet: postgresql-server-9.6.10-1.module+el8+2470+d1bafa0e.x86_64 1/3
Erasing : postgresql-9.6.10-1.module+el8+2470+d1bafa0e.x86_64 2/3
Erasing : libpq-12.4-1.el8_2.x86_64 3/3
Running scriptlet: libpq-12.4-1.el8_2.x86_64 3/3
Verifying : libpq-12.4-1.el8_2.x86_64 1/3
Verifying : postgresql-9.6.10-1.module+el8+2470+d1bafa0e.x86_64 2/3
Verifying : postgresql-server-9.6.10-1.module+el8+2470+d1bafa0e.x86_64 3/3
Installed products updated.
Removed:
libpq-12.4-1.el8_2.x86_64
postgresql-9.6.10-1.module+el8+2470+d1bafa0e.x86_64
postgresql-server-9.6.10-1.module+el8+2470+d1bafa0e.x86_64
Complete!
Reset the module
# dnf module reset -y postgresql
Updating Subscription Management repositories.
Last metadata expiration check: 1:27:18 ago on Tue 24 Nov 2020 01:34:58 PM EST.
Dependencies resolved.
=========================================================================================================
Package Architecture Version Repository Size
=========================================================================================================
Disabling module profiles:
postgresql/server
Resetting modules:
postgresql
Transaction Summary
=========================================================================================================
Complete!
Install the new module stream for the package
# dnf module install -y postgresql
Updating Subscription Management repositories.
Last metadata expiration check: 1:33:29 ago on Tue 24 Nov 2020 01:34:58 PM EST.
Dependencies resolved.
=========================================================================================================
Package Arch Version Repository Size
=========================================================================================================
Installing group/module packages:
postgresql-server x86_64 10.14-1.module+el8.2.0+7801+be0fed80 rhel-8-for-x86_64-appstream-rpms 5.0 M
Installing dependencies:
libpq x86_64 12.4-1.el8_2 rhel-8-for-x86_64-appstream-rpms 195 k
postgresql x86_64 10.14-1.module+el8.2.0+7801+be0fed80 rhel-8-for-x86_64-appstream-rpms 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
Downloading Packages:
(1/3): postgresql-10.14-1.module+el8.2.0+7801+be0fed80.x86_64.rpm 2.5 MB/s | 1.5 MB 00:00
(2/3): libpq-12.4-1.el8_2.x86_64.rpm 291 kB/s | 195 kB 00:00
(3/3): postgresql-server-10.14-1.module+el8.2.0+7801+be0fed80.x86_64.rpm 6.3 MB/s | 5.0 MB 00:00
---------------------------------------------------------------------------------------------------------
Total 8.3 MB/s | 6.7 MB 00:00
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing : 1/1
Installing : libpq-12.4-1.el8_2.x86_64 1/3
Installing : postgresql-10.14-1.module+el8.2.0+7801+be0fed80.x86_64 2/3
Running scriptlet: postgresql-server-10.14-1.module+el8.2.0+7801+be0fed80.x86_64 3/3
Installing : postgresql-server-10.14-1.module+el8.2.0+7801+be0fed80.x86_64 3/3
Running scriptlet: postgresql-server-10.14-1.module+el8.2.0+7801+be0fed80.x86_64 3/3
Verifying : postgresql-10.14-1.module+el8.2.0+7801+be0fed80.x86_64 1/3
Verifying : postgresql-server-10.14-1.module+el8.2.0+7801+be0fed80.x86_64 2/3
Verifying : libpq-12.4-1.el8_2.x86_64 3/3
Installed products updated.
Installed:
libpq-12.4-1.el8_2.x86_64
postgresql-10.14-1.module+el8.2.0+7801+be0fed80.x86_64
postgresql-server-10.14-1.module+el8.2.0+7801+be0fed80.x86_64
Complete!