YUM (short for Yellowdog Updater Modified) is an open source tool that was developed by Red Hat Inc for RPM-based systems. It is a high-level package management tool that’s used for easily installing, removing, updating, or searching software packages on systems or in network repositories. It allows us to use a CentOS base and third-party repositories that are created on remote or local servers to install individual packages or groups of packages automatically, after resolving their dependencies.
The main configuration file of YUM is /etc/yum.conf, and the main directory, which stores the repository configuration file, is /etc/yum.repos.d/. The repository configuration file has got a specific syntax, and it should end with a .repo extension in the /etc/yum.repos.d/ directory.
The repository configuration file contains the URL of the repository, the repo id, repo name, instructions to use GPG for checking package signatures, and an option to enable or disable the repository.
If you encounter below error:
# yum-config-manager --add-repo [repository_url] -bash: yum-config-manager: command not found
you may try installing the below package as per your choice of distribution.
| Distribution | Command |
|---|---|
| Debian | apt-get install yum-utils |
| Ubuntu | apt-get install yum-utils |
| Kali Linux | apt-get install yum-utils |
| CentOS | yum install yum-utils |
| Fedora | dnf install yum-utils |
| Raspbian | apt-get install yum-utils |
yum-config-manager command is a part of the package named yum-utils. Due to missing package on the system, it’s attained an error while running the command.
We can permanently enable or disable a repository by using the yum-config-manager utility. It makes necessary changes in the file stored in the /etc/yum.repos.d/ directory, as shown in command line here:
$ yum-config-manager --enable [repo id]
The yum-config-manager utility can also be used to create a client repo configuration file inside /etc/yum.repos.d, as shown in the following command line:
$ yum-config-manager --addrepo=http://repo.example.com/7/x86_64/