Chapter 11. Managing versions of Application Stream content

Procedure

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

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   # yum distro-sync

   Important

   This command must finish with the 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!.

   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:

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

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

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   # 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 because of the 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.

   • You need to reinstall binary extensions for interpreted languages, which are typically written in C or C++, after the new stream is enabled. It concerns, for example, packages installed by using the following commands:

     • The gem command from the ruby module. For more information, see How to switch Ruby streams in RHEL 8.
     • The npm command from the nodejs module
     • The cpan command from the perl module
     • The pecl command from the php module

Procedure

1. Display the available streams and their profiles:

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   # yum module list <module_name>

   For example, to list the available streams and their profiles of the postgresql module, enter:

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

   For example, create the /etc/dnf/modules.defaults.d/postgresql.yaml file with the following content to define 13 as the default stream and server as the default profile for the postgresql module:

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   ---
   document: modulemd-defaults
   version: 1
   data:
     module: postgresql
     stream: "13"
     profiles:
       13: [server]