YUM Repositories

About This Document

This document introduces YUM repositories and how OSG uses them.

Repositories

OSG hosts four public-facing repositories at repo.grid.iu.edu:

  • release: This repository contains software that we are willing to support and can be used by the general community.
  • contrib: RPMs contributed from outside the OSG.
  • testing: This repository contains software ready for testing. If you install packages from here, they may be buggy, but we will provide limited assistance in providing a migration path to a fixed version.
  • development: This repository is the bleeding edge. Installing from this repository may cause the host to stop functioning, and we will not assist in undoing any damage.

OSG’s RPM packages rely also on external packages provided by supported OSes and EPEL. You must have the following repositories available and enabled:

  • your OS repositories (SL 5/6/7, CentOS 5/6/7, or RHEL 5/6/7 repositories)
  • EPEL repositories
  • the OSG repositories you’d like to use

If one of these repositories is missing you may have missing dependencies.

We did not test other repositories. If you use packages from other repositories, like jpackage, dag, or rpmforge, you may encounter problems.

Enabling Repositories

In our advice on using yum you will learn many tricks and tips on using yum.

To use the packages in a repository without adding special options to the yum command the repository must be enabled.

Install the Yum Repositories required by OSG

The OSG RPMs currently support {{ supportedOs }}

OSG RPMs are distributed via the OSG yum repositories. Some packages depend on packages distributed via the EPEL repositories. So both repositories must be enabled.

Install EPEL

Install the EPEL repository, if not already present. Note: This enables EPEL by default. Choose the right version to match your OS version.

# EPEL 5 (For RHEL 5, CentOS 5, and SL 5)
$ curl -O https://dl.fedoraproject.org/pub/epel/epel-release-latest-5.noarch.rpm
$ rpm -Uvh epel-release-latest-5.noarch.rpm
# EPEL 6 (For RHEL 6, CentOS 6, and SL 6)
$ rpm -Uvh https://dl.fedoraproject.org/pub/epel/epel-release-latest-6.noarch.rpm
# EPEL 7 (For RHEL 7, CentOS 7, and SL 7)
$ rpm -Uvh https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm

WARNING: if you have your own mirror or configuration of the EPEL repository, you MUST verify that the OSG repository has a better yum priority than EPEL (details). Otherwise, you will have strange dependency resolution (depsolving) issues.

Install the Yum priorities package

For packages that exist in both OSG and EPEL repositories, it is important to prefer the OSG ones or else OSG software installs may fail. Installing the Yum priorities package enables the repository priority system to work.

  1. Choose the correct package name based on your operating system’s major version:

    • For EL 5 systems, use yum-priorities
    • For EL 6 and EL 7 systems, use yum-plugin-priorities

  2. Install the Yum priorities package: yum install *PACKAGE* Replace PACKAGE with the package name from the previous step.

  3. Ensure that /etc/yum.conf has the following line in the [main] section (particularly when using ROCKS), thereby enabling Yum plugins, including the priorities one:

    plugins=1

    NOTE: If you do not have a required key you can force the installation using --nogpgcheck=; e.g., =yum install --nogpgcheck yum-priorities.

Install OSG Repositories

  1. If you are upgrading from OSG 3.1 (or 3.2) to OSG 3.2 (or 3.3), remove the old OSG repository definition files and clean the Yum cache:

# yum clean all # rpm -e osg-release

This step ensures that local changes to *.repo files will not block the installation of the new OSG repositories. After this step, *.repo files that have been changed will exist in /etc/yum.repos.d/ with the *.rpmsave extension. After installing the new OSG repositories (the next step) you may want to apply any changes made in the *.rpmsave files to the new *.repo files. 2. Install the OSG repositories using one of the following methods depending on your EL version: 1. For EL versions greater than EL5, install the files directly from repo.grid.iu:

    ```
    rpm -Uvh URL
    ```

    Where `URL` is one of the following:

    | Series      | EL6 URL (for RHEL 6, CentOS 6, or SL 6) | EL7 URL (for RHEL 7, CentOS 7, or SL 7) |
    |----------   | ----------------------------------------| --------------------------------------- | 
    | **OSG 3.2** | `https://repo.grid.iu.edu/osg/3.2/osg-3.2-el6-release-latest.rpm`  | N/A
    | **OSG 3.3** | `https://repo.grid.iu.edu/osg/3.3/osg-3.3-el6-release-latest.rpm`  | `https://repo.grid.iu.edu/osg/3.3/osg-3.3-el7-release-latest.rpm` |

2. For EL5, download the repo file and install it using the following:
    ```
    # curl -O https://repo.grid.iu.edu/osg/3.2/osg-3.2-el5-release-latest.rpm
    # rpm -Uvh osg-3.2-el5-release-latest.rpm
    ```

Priorities

Make sure you installed the Yum priorities plugin, as described above. Not doing so is a common mistake that causes failed installations.

The only OSG repository enabled by default is the release one. If you want to enable another one, such as osg-testing, then edit its file (e.g. /etc/yum.repos.d/osg-testing.repo) and change the enabled option from 0 to 1:

[osg-testing]
name=OSG Software for Enterprise Linux 5 - Testing - $basearch
#baseurl=http://repo.grid.iu.edu/osg/3.2/el5/testing/$basearch
mirrorlist=http://repo.grid.iu.edu/mirror/osg/3.2/el5/testing/$basearch
failovermethod=priority
priority=98
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-OSG

If you have your own mirror or configuration of the EPEL repository, you MUST verify that the OSG repository has a better yum priority than EPEL. Otherwise, you will have strange dependency resolution issues.

References