Finding CentOS 8 content

The following sections describe how to locate and examine content in the AppStream and BaseOS repositories in CentOS.

Searching for a package describes how to search for packages providing desired content.
Listing available modules describes how to list available modules and find out details about them.
Example: Finding out details about a module contains an example of steps needed to examine a module in more detail.
Commands for listing content provides a reference of the commands useful for inspecting content.

Searching for a package

This section describes steps needed for finding a package providing a particular application or other content.

Prerequisites

Name of the desired application or content must be known

Procedure

Search for a package with a text string, such as application name:
```
$ yum search "text string"
```
View details about a package:
```
$ yum info package
```

Listing available modules

This section describes steps needed for finding what modules are available and what their details are.

Procedure

List module streams available to your system:
```
$ yum module list
```
The output of this command lists module streams with name, stream, profiles, and summary on a separate line.
Display details about a module, including a description, a list of all profiles, and a list of all provided packages:
```
$ yum module info module-name
```
Optional: You can also list which of these packages are installed by each of module profiles:
```
$ yum module info --profile module-name
```
Display the current status of a module, including enabled streams and installed profiles:
```
$ yum module list module-name
```

Additional resources

Introduction to modules

Example: Finding out details about a module

This example shows how to locate a module in the AppStream repository and how to find out more about its contents.

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

Procedure

List available modules:

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

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

Examine details of the postgresql module:

$ yum module info postgresql

Name             : postgresql
Stream           : 10 [d][a]
Version          : 820190104140132
Context          : 9edba152
Profiles         : client, server [d]
Default profiles : server
Repo             : appstream-internal-nightly
Summary          : PostgreSQL server and client module
Description      : (...)
(...)

Name             : postgresql
Stream           : 9.6
Version          : 820190104140337
Context          : 9edba152
Profiles         : client, server [d]
Default profiles : server
Repo             : appstream-internal-nightly
Summary          : PostgreSQL server and client module
Description      : (...)
(...)

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

Because no stream is specified, all streams are used for the listing.

Examine profiles available in stream 10 of the postgresql module:

$ yum module info --profile postgresql:10
(...)
Name   : postgresql:10:820190104140132:9edba152:x86_64
client : postgresql
server : postgresql-server

Each of the profiles installs a different set of packages, including their dependencies.

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

# yum install @postgresql
Dependencies resolved.
====================================================================
 Package           Version                         Repository Size
====================================================================
Installing group/module packages:
 postgresql-server 10.6-1.module+el8+2469+5ecd5aae appstream  5.1 M
Installing dependencies:
 libpq             10.5-1.el8                      appstream  188 k
 postgresql        10.6-1.module+el8+2469+5ecd5aae 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: 27 M
Is this ok [y/N]: y
(...)

The stream 10 is enabled and packages in its profile server installed.

Inspect the current status of the postgresql module:

$ yum module list postgresql
Name       Stream    Profiles                Summary
postgresql 10 [d][e] client, server [d] [i]  (...)
postgresql 9.6       client, server [d]      (...)

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.

Commands for listing content

This section lists commonly used commands for finding content and its details.

Command list

List available packages

$ yum list available

Search for a package using arbitrary text string

$ yum search "text string"

Display details for a package

$ yum info package

Find out which modules provide a package

$ yum module provides package

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

List available modules

$ yum module list

Display details of a module

$ yum module info module-name

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

$ yum module info --profile module-name

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

$ yum module info --profile module-name:stream

Display the current status of a module

$ yum module list module-name