Chapter 6. Discovering hosts on a network

Procedure

1. Install foreman-discovery-image on Satellite Server:

   # satellite-maintain packages install foreman-discovery-image

   The foreman-discovery-image package installs the Discovery ISO to the /usr/share/foreman-discovery-image/ directory. The package also extracts the PXE boot image to the /var/lib/tftpboot/boot/fdi-image directory.

2. If you want to use Capsule Server, install the Discovery plugin on Capsule Server:

   # satellite-installer \
   --enable-foreman-proxy-plugin-discovery

3. If you want to use Capsule Server, install foreman-discovery-image on Capsule Server:

   # satellite-maintain packages install foreman-discovery-image

   The package also extracts the PXE boot image to the /var/lib/tftpboot/boot/fdi-image directory.

4. Configure the Discovery Capsule for the subnet with discoverable hosts:

   1. In the Satellite web UI, navigate to Infrastructure > Subnets.
   2. Select a subnet.
   3. On the Capsules tab, select the Discovery Capsule that you want to use.

   Perform this for each subnet that you want to use.

1. If a discovered host uses a subnet defined in Satellite, the host uses the first organization and location associated with the subnet.
2. If the default location and organization is configured in global settings, the discovered hosts are placed in this organization and location. To configure these settings, navigate to Administer > Settings > Discovery and select values for the Discovery organization and Discovery location settings. Ensure that the subnet of discovered host also belongs to the selected organization and location, otherwise Satellite refuses to set it for security reasons.
3. If none of the previous conditions is met, Satellite assigns the first organization and location ordered by name.

Procedure

1. In the Satellite web UI, navigate to Hosts > Discovered hosts.
2. Select the host you want to provision and click Provision to the right of the list.

3. Select one of the following options:

   • To provision a host from a host group, select a host group, organization, and location, and then click Create Host.
   • To provision a host with further customization, click Customize Host and enter the additional details you want to specify for the new host.

4. Verify that the fields are populated with values. Note in particular:

   • The Name from the Host tab becomes the DNS name.
   • Satellite Server automatically assigns an IP address for the new host.
   • Satellite Server automatically populates the MAC address from the Discovery results.
5. Ensure that Satellite Server automatically selects the Managed, Primary, and Provision options for the first interface on the host. If not, select them.
6. Click the Operating System tab, and verify that all fields contain values. Confirm each aspect of the operating system.

7. In Provisioning templates, click Resolve to check if the new host can identify the correct provisioning templates. The host must resolve to the following provisioning templates:

   • Discovery kexec: Discovery Red Hat kexec
   • Provisioning template: Kickstart default
8. Click Submit to save the host details.

CLI procedure

1. Identify the discovered host to provision:

   # hammer discovery list

2. Select the host and provision it by using a host group. Set a new host name with the --new-name option:

   # hammer discovery provision \
   --build true \
   --enabled true \
   --hostgroup "My_Host_Group" \
   --location "My_Location" \
   --managed true \
   --name "My_Host_Name" \
   --new-name "My_New_Host_Name" \
   --organization "My_Organization"

   This removes the host from the discovered host listing and creates a host entry with the provisioning settings. The Discovery image automatically reboots the host to PXE or initiates kernel execution. The host detects the DHCP service and starts installing the operating system. The rest of the process is identical to the normal PXE workflow described in Section 4.3, “Creating hosts with unattended provisioning”.

Procedure

1. In the Satellite web UI, navigate to Configure > Discovery rules, and select Create Rule.
2. In the Name field, enter a name for the rule.
3. In the Search field, enter the rules to determine whether to provision a host. This field provides suggestions for values you enter and allows operators for multiple rules. For example: cpu_count > 8.
4. From the Host Group list, select the host group to use as a template for this host.

5. In the Hostname field, enter the pattern to determine host names for multiple hosts. This uses the same ERB syntax that provisioning templates use. The host name can use the @host attribute for host-specific values and the rand macro for a random number or the sequence_hostgroup_param_next macro for incrementing the value. For more information about provisioning templates, see Section 2.12, “Provisioning templates” and the API documentation.

   • myhost-<%= sequence_hostgroup_param_next("EL7/MyHostgroup", 10, "discovery_host") %>
   • myhost-<%= rand(99999) %>
   • abc-<%= @host.facts['bios_vendor'] %>-<%= rand(99999) %>
   • xyz-<%= @host.hostgroup.name %>
   • srv-<%= @host.discovery_rule.name %>

   • server-<%= @host.ip.gsub('.','-') + '-' + @host.hostgroup.subnet.name %>

     When creating host name patterns, ensure that the resulting host names are unique, do not start with numbers, and do not contain underscores or dots. A good approach is to use unique information provided by Facter, such as the MAC address, BIOS, or serial ID.

6. In the Hosts limit field, enter the maximum number of hosts that you can provision with the rule. Enter 0 for unlimited.
7. In the Priority field, enter a number to set the precedence the rule has over other rules. Rules with lower values have a higher priority.
8. From the Enabled list, select whether you want to enable the rule.
9. To set a different provisioning context for the rule, click the Organizations and Locations tabs and select the contexts you want to use.
10. Click Submit to save your rule.

11. In the Satellite web UI, navigate to Hosts > Discovered Host and select one of the following two options:

    • From the Discovered hosts list on the right, select Auto-Provision to automatically provisions a single host.
    • On the upper right of the window, click Auto-Provision All to automatically provisions all hosts.

CLI procedure

1. Create the rule by using Hammer:

   # hammer discovery-rule create \
   --enabled true \
   --hostgroup "My_Host_Group" \
   --hostname "hypervisor-<%= rand(99999) %>" \
   --hosts-limit 5 \
   --name "My_Hypervisor" \
   --priority 5 \
   --search "cpu_count  > 8"

2. Automatically provision a host with the hammer discovery auto-provision command:

   # hammer discovery auto-provision --name "macabcdef123456"

Procedure

1. Create the following directory structure:

   .
   ├── autostart.d
   │   └── 01_zip.sh
   ├── bin
   │   └── ntpdate
   ├── facts
   │   └── test.rb
   └── lib
       ├── libcrypto.so.1.0.0
       └── ruby
           └── test.rb

   • The autostart.d directory contains scripts that are executed in POSIX order by the Discovery kernel when it starts but before the host is registered to Satellite.
   • The bin directory is added to the $PATH variable; you can place binary files in this directory and use them in the autostart scripts.
   • The facts directory is added to the FACTERLIB variable so that custom facts can be configured and sent to Satellite.
   • The lib directory is added to the LD_LIBRARY_PATH variable and lib/ruby is added to the RUBYLIB variable, so that binary files in /bin can be executed correctly.

2. After creating the directory structure, create a .zip file archive with the following command:

   # zip -r my_extension.zip .

3. Inform the Discovery kernel of the extensions it must use. Place your zip files on your TFTP server with the Discovery image and customize the Discovery PXE boot with the fdi.zips parameter where the paths are relative to the TFTP root.

   For example, if you have two archives at $TFTP/zip1.zip and $TFTP/boot/zip2.zip, use the following syntax:

   fdi.zips=zip1.zip,boot/zip2.zip

   For more information, see Section 6.3.3, “Customizing the Discovery PXE boot”.