6.6. Channels

6.6.1.1. Relevant Channels

As shown in Figure 6-6, the Relevant Channels page is shown by default when you click Software Channels in the left navigation bar. It displays a list of channels now associated with your systems. Links within this list go to different tabs of the Software Channel Details page. Clicking on a channel name takes you to the Details tab. Clicking on the packages number takes you to the Packages tab. And clicking on the systems number takes you to the Subscribed Systems tab. Refer to Section 6.6.1.3 Software Channel Details for details.

6.6.1.2. All Channels

The All Channels page can be retrieved by clicking All below Software Channels in the left navigation bar. It works identically to the Relevant button with one exception; It displays all software channels offered by Red Hat Network, regardless of whether you have systems associated with them.

6.6.1.3. Software Channel Details

If you click on the name of a channel, the Software Channel Details page will appear. This page is broken down into the following tabs:

6.6.3.1. Relevant ISOs

The Relevant ISOs page is shown by default when you click Easy ISOs in the left navigation bar. It displays a list of ISOs by channel now associated with your systems. Links within this list go to the Downloads tab of the Channel Details page. Refer to Section 6.6.3 Easy ISOs for instructions on use.

6.6.3.2. All ISOs

The All ISOs page can be retrieved by clicking All below Easy ISOs in the left navigation bar. It works identically to the Relevant button with one exception; It displays all ISOs available to you through Red Hat Network, regardless of whether you have systems associated with the related channels. Refer to Section 6.6.3 Easy ISOs for instructions on use.

6.6.5.1. Software Package Install

Only software packages included in a system's subscribed channels can be installed or updated on that system.

	Important
	If you use scheduled package installation, the packages will be installed via the RHN Daemon. You must have the RHN Daemon enabled on your systems. Refer to Chapter 3 Red Hat Network Daemon for more details.

To apply Errata Updates, refer to Section 6.5.2.1 Apply Errata Updates. To upgrade and install packages through the Systems category, use the Packages tab of the System Details page. Refer to Section 6.4.2.6 System Details for instructions.

— Within the Channels category, you may install an individual package on multiple entitled systems by following these steps:

1. Select Channels => Software Channels from the top and left navigation bars.

2. Click on the name of the channel that contains the package to be installed.

3. On the Software Channel Details page, click on the Packages tab.

4. Click on the name of the package you want to install.

5. On the Package Details page, click on the Target Systems tab.

6. Select the entitled systems you want to install the package on.

7. Click on the Install Packages button.

8. Confirm the action.

9. The action is added to the Pending Actions list under the Schedule tab in the top navigation bar.

6.6.5.2. Package Download

If you do not want to schedule a package installation, you can download the packages immediately. If you download the packages, you must install them manually.

To download packages through the Systems category, refer to Section 6.4.2.6 System Details.

To download individual RPMs and SRPMs through the Channels category, follow these steps:

1. Select Channels => Software Channels from the top and left navigation bars.

2. Click on the name of the channel that contains the package to be downloaded.

3. On the Software Channel Details page, click on the Packages tab.

4. Click on the name of the package that you want to download.

5. On the Package Details page, click the Download RPM or Download SRPM link on the bottom right-hand corner.

6. Confirm the action.

The next step is to install the packages manually. Refer to Section 2.3.5.2 Manual Package Installation for details.

6.6.5.3. Package Details

If you click on the name of any package in the website, the Package Details page will appear. This page contains the following tabs:

6.6.6.1. Preparing Systems for Config Management

For a system to have its configuration managed through RHN, it must have the appropriate tools and config-enable file installed. These tools may already be installed on your system, especially if you kickstarted the system with configuration management functionality. If not, they can be found within the RHN Provisioning child channel for your distribution. Download and install the latest rhncfg* packages.

Next, you must place a config-enable file on the system to have config actions scheduled. This file is required to allow configuration management on the system while preventing inadvertent and potentially dangerous changes. To create this file, issue the following commands as root. First, create the necessary directory:

mkdir -p /etc/sysconfig/rhn/allowed-actions/configfiles

Then, you should decide exactly what actions should be allowed by system administrators. The following modes are available:

• deploy — Install configuration files from the central repository on the system. Without this set, the configuration management interface provides no real value for this system.

• verify — Identify any differences between configuration files on the system and those associated with it in the central repository.

• diff — Display differences between configuration files on the system and those associated with it in the central repository.

• upload — Send any files from the system to the central repository. This is similar to granting root privileges on the machine.

• mtime_upload — Send files modified since a certain date and time from the system to the central repository.

• all — Enable all of these modes for configuration management on the system.

To set individual modes, issue this command (repeatedly, as root), appending the mode name to the end:

touch /etc/sysconfig/rhn/allowed-actions/configfiles/mode

To grant full configuration management access, issue this command:

touch /etc/sysconfig/rhn/allowed-actions/configfiles/all

Your system should now be ready for config management through RHN. Command line options also exist for many of these functions. Refer to Appendix A Command Line Config Management Tools for instructions.

6.6.6.2. Manage Config Channels ⇒ Config Channels —

There are two types of configuration channels: global channels and system-specific channels. A global channel contains configuration files developed across your organization. These may well be applicable to multiple systems. A system-specific channel consists of local override configuration files tied to particular systems. These files take precedent over all other configurations.

6.6.6.3. Manage Config Channels ⇒ Manage Files —

The Manage Files page lists the configuration files managed by your organization. Clicking the number in the Config Channels column takes you to a list of channels containing the file. From there you can access tabs of the Configuration Channel Details page. Clicking the number in the Latest Revision column takes you to the Configuration File Details page. Refer to Section 6.6.6.6 Configuration File Details — for instructions.

6.6.6.4. Manage Config Channels ⇒ Quota —

The Quota page displays the amount of disk space alloted and used for storing configuration files. A summary of available and used space can be found at the top, while individual file use is listed within the table. Click the filename to go to the Configuration File Details page. Refer to Section 6.6.6.6 Configuration File Details — for instructions. Click the config channel name to access the Configuration Channel Details page. Refer to Section 6.6.6.5 Configuration Channel Details — for instructions.

6.6.6.5. Configuration Channel Details —

If you click on the name of a channel in a list, the Configuration Channel Details page will appear. This page contains the following tabs:

6.6.6.6. Configuration File Details —

If you click on the name or number of a file in a list, the Configuration File Details page will appear. You may remove the file at anytime by clicking delete file in the upper-right corner of the page. This page contains the following tabs:

6.6.6.7. Including Macros in your Configuration Files

Being able to store and share identical configurations is useful, but what if you have many variations of the same configuration file? What do you do if you have configuration files that differ only in system-specific details, such as hostname and MAC address?

In traditional file management, you would be required to upload and distribute each file separately, even if the distinction is nominal and the number of variations is in the hundreds or thousands. RHN addresses this by allowing the inclusion of macros, or variables, within the configuration files it manages for Provisioning-entitled systems. In addition to variables for custom system information, the following standard macros are supported:

• rhn.system.sid

• rhn.system.profile_name

• rhn.system.description

• rhn.system.hostname

• rhn.system.ip_address

• rhn.system.custom_info(key_name)

• rhn.system.net_interface.ip_address(eth_device)

• rhn.system.net_interface.netmask(eth_device)

• rhn.system.net_interface.broadcast(eth_device)

• rhn.system.net_interface.hardware_address(eth_device)

• rhn.system.net_interface.driver_module(eth_device)

To use this powerful feature, either upload or create a configuration file through the Configuration Channel Details page. Then, open its Configuration File Details page and include the supported macros of your choosing. Ensure the delimiters used to offset your variables match those set in the Macro Start Delimiter and Macro End Delimiter fields and do not conflict with other characters in the file. The delimiters must be two characters and cannot contain the percent (%) symbol.

As an example, you may have a file applicable to all of your servers that differs only in IP address and hostname. Rather than manage a separate configuration file for each server, you may create a single file, say server.conf, with the IP address and hostname macros included, like so:

hostname={@ rhn.system.hostname @}
ip_address={@ rhn.system.net_interface.ip_address(eth0) @}

Upon delivery of the file to individual systems, whether through a scheduled action in the RHN website or at the command line with the Red Hat Network Configuration Client (rhncfg-client), the variables will be substituted with the actual hostname and IP address of the system, as recorded in RHN's System Profile, such as:

hostname=test.example.domain.com
ip_address=177.18.54.7

To capture custom system information, insert the key label into the custom information macro (rhn.system.custom_info). For instance, if you developed a key labeled "asset" you can add it to the custom information macro in a configuration file to have the value substituted on any system containing it. The macro would look like this:

asset={@ rhn.system.custom_info(asset) @}

Upon deployment of the file to a system containing a value for that key, the macro gets translated, such as:

asset=Example#456

To include a default value, for instance if one is required to prevent errors, you can append it to the custom information macro, like so:

asset={@ rhn.system.custom_info(asset) = 'Asset #' @}

This default will be overridden by the actual value on any system containing it. For instructions on developing custom system information keys, refer to Section 6.4.9 Custom System Info — .

Using the Red Hat Network Configuration Manager (rhncfg-manager) will not translate or alter files, as that tool is system agnostic. Binary files cannot be interpolated.