Appendix C. Building cloud images for Red Hat Satellite
Use this section to build and register images to Red Hat Satellite.
You can use a preconfigured Red Hat Enterprise Linux KVM guest QCOW2 image:
These images contain cloud-init
. To function properly, they must use ec2-compatible metadata services for provisioning an SSH key.
For the KVM guest images:
-
The
root
account in the image is disabled, butsudo
access is granted to a special user namedcloud-user
. -
There is no
root
password set for this image. Theroot
password is locked in/etc/shadow
by placing!!
in the second field.
If you want to create custom Red Hat Enterprise Linux images, see Composing a customized Red Hat Enterprise Linux 9 Image or Composing a customized Red Hat Enterprise Linux 8 Image.
C.1. Creating custom Red Hat Enterprise Linux images
Prerequisites
- Use a Linux host machine to create an image. In this example, we use a Red Hat Enterprise Linux 7 Workstation.
-
Use
virt-manager
on your workstation to complete this procedure. If you create the image on a remote server, connect to the server from your workstation withvirt-manager
. - A Red Hat Enterprise Linux 7 or 6 ISO file (see Red Hat Enterprise Linux 7.4 Binary DVD or Red Hat Enterprise Linux 6.9 Binary DVD).
For more information about installing a Red Hat Enterprise Linux Workstation, see Red Hat Enterprise Linux 7 Installation Guide.
Before you can create custom images, install the following packages:
Install
libvirt
,qemu-kvm
, and graphical tools:# yum install virt-manager virt-viewer libvirt qemu-kvm
Install the following command line tools:
# yum install virt-install libguestfs-tools-c
In the following procedures, enter all commands with the [root@host]#
prompt on the workstation that hosts the libvirt
environment.
C.2. Supported clients in registration
Satellite supports the following operating systems and architectures for registration.
- Supported host operating systems
The hosts can use the following operating systems:
- Red Hat Enterprise Linux 9, 8, 7
- Red Hat Enterprise Linux 6 with the ELS Add-On
- Supported host architectures
The hosts can use the following architectures:
- i386
- x86_64
- s390x
- ppc_64
C.3. Configuring a host for registration
Configure your host for registration to Satellite Server or Capsule Server. You can use a configuration management tool to configure multiple hosts at once.
Prerequisites
- The host must be using a supported operating system. For more information, see Section C.2, “Supported clients in registration”.
- The system clock on your Satellite Server and any Capsule Servers must be synchronized across the network. If the system clock is not synchronized, SSL certificate verification might fail. For example, you can use the Chrony suite for timekeeping.
Procedure
Enable and start a time-synchronization tool on your host. The host must be synchronized with the same NTP server as Satellite Server and any Capsule Servers.
On Red Hat Enterprise Linux 7 and later:
# systemctl enable --now chronyd
On Red Hat Enterprise Linux 6:
# chkconfig --add ntpd # chkconfig ntpd on # service ntpd start
Deploy the SSL CA file on your host so that the host can make a secured registration call.
- Find where Satellite stores the SSL CA file by navigating to Administer > Settings > Authentication and locating the value of the SSL CA file setting.
-
Transfer the SSL CA file to your host securely, for example by using
scp
. - Login to your host by using SSH.
Copy the certificate to the truststore:
# cp My_SSL_CA_file.pem /etc/pki/ca-trust/source/anchors
Update the truststore:
# update-ca-trust
C.4. Registering a host
You can register a host by using registration templates and set up various integration features and host tools during the registration process.
Prerequisites
-
Your user account has a role assigned that grants the
create_hosts
permission. - You must have root privileges on the host that you want to register.
- You have configured the host for registration. For more information, see Section C.3, “Configuring a host for registration”.
- An activation key must be available for the host. For more information, see Managing Activation Keys in Managing content.
-
Optional: If you want to register hosts to Red Hat Insights, you must synchronize the
rhel-8-for-x86_64-baseos-rpms
andrhel-8-for-x86_64-appstream-rpms
repositories and make them available in the activation key that you use. This is required to install theinsights-client
package on hosts. - Red Hat Satellite Client 6 repository for the operating system version of the host is synchronized on Satellite Server and enabled in the activation key you use. For more information, see Importing Content in Managing content. This repository is required for the remote execution pull client, Puppet agent, Tracer, and other tools.
- If you want to use Capsule Servers instead of your Satellite Server, ensure that you have configured your Capsule Servers accordingly. For more information, see Configuring Capsule for Host Registration and Provisioning in Installing Capsule Server.
- If your Satellite Server or Capsule Server is behind an HTTP proxy, configure the Subscription Manager on your host to use the HTTP proxy for connection. For more information, see How to access Red Hat Subscription Manager (RHSM) through a firewall or proxy in the Red Hat Knowledgebase.
Procedure
- In the Satellite web UI, navigate to Hosts > Register Host.
- Enter the details for how you want the registered hosts to be configured.
- On the General tab, in the Activation Keys field, enter one or more activation keys to assign to hosts.
-
Click Generate to generate a
curl
command. -
Run the
curl
command asroot
on the host that you want to register. After registration completes, any Ansible roles assigned to a host group you specified when configuring the registration template will run on the host.
The registration details that you can specify include the following:
- On the General tab, in the Capsule field, you can select the Capsule to register hosts through. A Capsule behind a load balancer takes precedence over a Capsule selected in the Satellite web UI as the content source of the host.
On the General tab, you can select the Insecure option to make the first call insecure. During this first call, the host downloads the CA file from Satellite. The host will use this CA file to connect to Satellite with all future calls making them secure.
Red Hat recommends that you avoid insecure calls.
If an attacker, located in the network between Satellite and a host, fetches the CA file from the first insecure call, the attacker will be able to access the content of the API calls to and from the registered host and the JSON Web Tokens (JWT). Therefore, if you have chosen to deploy SSH keys during registration, the attacker will be able to access the host using the SSH key.
- On the Advanced tab, in the Repositories field, you can list repositories to be added before the registration is performed. You do not have to specify repositories if you provide them in an activation key.
On the Advanced tab, in the Token lifetime (hours) field, you can change the validity duration of the JSON Web Token (JWT) that Satellite uses for authentication. The duration of this token defines how long the generated
curl
command works.Note that Satellite applies the permissions of the user who generates the
curl
command to authorization of hosts. If the user loses or gains additional permissions, the permissions of the JWT change too. Therefore, do not delete, block, or change permissions of the user during the token duration.The scope of the JWTs is limited to the registration endpoints only and cannot be used anywhere else.
CLI procedure
-
Use the
hammer host-registration generate-command
to generate thecurl
command to register the host. -
On the host that you want to register, run the
curl
command asroot
.
For more information, see the Hammer CLI help with hammer host-registration generate-command --help
.
Ansible procedure
-
Use the
redhat.satellite.registration_command
module.
For more information, see the Ansible Module documentation with ansible-doc redhat.satellite.registration_command
.
API procedure
-
Use the
POST /api/registration_commands
resource.
For more information, see the full API reference at https://satellite.example.com/apidoc/v2.html
.
C.5. Installing and configuring Puppet agent manually
You can install and configure the Puppet agent on a host manually. A configured Puppet agent is required on the host for Puppet integration with your Satellite. For more information about Puppet, see Managing configurations using Puppet integration.
Prerequisites
- Puppet must be enabled in your Satellite. For more information, see Enabling Puppet Integration with Satellite in Managing configurations using Puppet integration.
- The host must have a Puppet environment assigned to it.
- Red Hat Satellite Client 6 repository for the operating system version of the host is synchronized on Satellite Server, available in the content view and the lifecycle environment of the host, and enabled for the host. For more information, see Changing the repository sets status for a host in Satellite in Managing content.
Procedure
-
Log in to the host as the
root
user. Install the Puppet agent package.
On hosts running Red Hat Enterprise Linux 8 and above:
# dnf install puppet-agent
On hosts running Red Hat Enterprise Linux 7 and below:
# yum install puppet-agent
Add the Puppet agent to
PATH
in your current shell using the following script:. /etc/profile.d/puppet-agent.sh
Configure the Puppet agent. Set the
environment
parameter to the name of the Puppet environment to which the host belongs:# puppet config set server satellite.example.com --section agent # puppet config set environment My_Puppet_Environment --section agent
Start the Puppet agent service:
# puppet resource service puppet ensure=running enable=true
Create a certificate for the host:
# puppet ssl bootstrap
- In the Satellite web UI, navigate to Infrastructure > Capsules.
- From the list in the Actions column for the required Capsule Server, select Certificates.
- Click Sign to the right of the required host to sign the SSL certificate for the Puppet agent.
On the host, run the Puppet agent again:
# puppet ssl bootstrap
C.6. Completing the Red Hat Enterprise Linux 7 image
Procedure
Update the system:
# yum update
Install the
cloud-init
packages:# yum install cloud-utils-growpart cloud-init
Open the
/etc/cloud/cloud.cfg
configuration file:# vi /etc/cloud/cloud.cfg
Under the heading
cloud_init_modules
, add:- resolv-conf
The
resolv-conf
option automatically configures theresolv.conf
when an instance boots for the first time. This file contains information related to the instance such asnameservers
,domain
and other options.Open the
/etc/sysconfig/network
file:# vi /etc/sysconfig/network
Add the following line to avoid problems accessing the EC2 metadata service:
NOZEROCONF=yes
Un-register the virtual machine so that the resulting image does not contain the same subscription details for every instance cloned based on it:
# subscription-manager repos --disable=* # subscription-manager unregister
Power off the instance:
# poweroff
On your Red Hat Enterprise Linux Workstation, connect to the terminal as the root user and navigate to the
/var/lib/libvirt/images/
directory:# cd /var/lib/libvirt/images/
Reset and clean the image using the
virt-sysprep
command so it can be used to create instances without issues:# virt-sysprep -d rhel7
Reduce image size using the
virt-sparsify
command. This command converts any free space within the disk image back to free space within the host:# virt-sparsify --compress rhel7.qcow2 rhel7-cloud.qcow2
This creates a new
rhel7-cloud.qcow2
file in the location where you enter the command.
C.7. Completing the Red Hat Enterprise Linux 6 image
Procedure
Update the system:
# yum update
Install the
cloud-init
packages:# yum install cloud-utils-growpart cloud-init
Edit the
/etc/cloud/cloud.cfg
configuration file and undercloud_init_modules
add:- resolv-conf
The
resolv-conf
option automatically configures theresolv.conf
configuration file when an instance boots for the first time. This file contains information related to the instance such asnameservers
,domain
, and other options.To prevent network issues, create the
/etc/udev/rules.d/75-persistent-net-generator.rules
file as follows:# echo "#" > /etc/udev/rules.d/75-persistent-net-generator.rules
This prevents
/etc/udev/rules.d/70-persistent-net.rules
file from being created. If/etc/udev/rules.d/70-persistent-net.rules
is created, networking might not function properly when booting from snapshots (the network interface is created as "eth1" rather than "eth0" and IP address is not assigned).Add the following line to
/etc/sysconfig/network
to avoid problems accessing the EC2 metadata service:NOZEROCONF=yes
Un-register the virtual machine so that the resulting image does not contain the same subscription details for every instance cloned based on it:
# subscription-manager repos --disable=* # subscription-manager unregister # yum clean all
Power off the instance:
# poweroff
On your Red Hat Enterprise Linux Workstation, log in as root and reset and clean the image using the
virt-sysprep
command so it can be used to create instances without issues:# virt-sysprep -d rhel6
Reduce image size using the
virt-sparsify
command. This command converts any free space within the disk image back to free space within the host:# virt-sparsify --compress rhel6.qcow2 rhel6-cloud.qcow2
This creates a new
rhel6-cloud.qcow2
file in the location where you enter the command.NoteYou must manually resize the partitions of instances based on the image in accordance with the disk space in the flavor that is applied to the instance.
C.7.1. Next steps
- Repeat the procedures for every image that you want to provision with Satellite.
- Move the image to the location where you want to store for future use.
C.8. Next steps
- Repeat the procedures for every image that you want to provision with Satellite.
- Move the image to the location where you want to store for future use.