Appendix C. Building Cloud Images for Red Hat Satellite

1. Using your web browser, download the Red Hat Enterprise Linux binary ISO file to a temporary location, for example, the Downloads directory.

2. Copy the Red Hat Enterprise Linux binary ISO file to the /var/lib/libvirt/images/ directory.

   [root@host]# cp ~/home/user/Downloads/rhel-server-7.4-x86_64-dvd.iso /var/lib/libvirt/images/

3. Verify that virtbr0 is the virtual bridge:

   [root@host]# ip a

4. Start libvirtd:

   [root@host]# systemctl start libvirtd

5. Navigate to the /var/lib/libvirt/images/ directory:

   [root@host]# cd /var/lib/libvirt/images/

6. Prepare the QEMU image:

   [root@host]# qemu-img create -f qcow2 rhel7.qcow2 8G

7. Start the installation using virt-install. Use the following example as a guide:

   [root@host]# virt-install --virt-type qemu --name rhel7 --ram 2048 \
   --cdrom rhel-server-7.4-x86_64-dvd.iso \
   --disk rhel7.qcow2,format=qcow2 \
   --network=bridge:virbr0 --graphics vnc,listen=0.0.0.0 \
   --noautoconsole --os-type=linux --os-variant=rhel7

   Note

   For GUI users, if the instance does not launch automatically, enter the virt-manager command to view the console:

   [root@host]# virt-manager

8. Follow the steps of the Red Hat Enterprise Linux installation wizard.

   1. For the installation source, add an HTTP link to your repository in Red Hat Satellite, for example satellite.example.com/pub/export/RHEL7/content/dist/rhel/server/7/7Server/x86_64/os/
   2. For the type of devices your installation uses, select Auto-detected installation media.
   3. For the type of installation destination, select Local Standard Disks.
   4. For other storage options, select Automatically configure partitioning.
   5. For software selection, select Minimal Install.
   6. Set the network interface to ON to ensure the interface activates on system start.
   7. Enter a host name, and click Apply.
   8. Enter a root password.
9. When the installation completes, reboot the instance and log in as the root user.

10. Confirm that the network interface is up and that the IP address is assigned:

    # ip a

11. Confirm that the hostname is correct:

    # hostname

12. Create a /etc/NetworkManager/conf.d/XX-cloud-image.conf file where XX is a two-digit number that indicates order of precedence. Add the following contents to the file:

    [main]
    dns=none

13. Proceed to Configuring a Host for Registration.

1. Start the installation using virt-install:

   [root@host]# qemu-img create -f qcow2 rhel6.qcow2 4G
   [root@host]# virt-install --connect=qemu:///system --network=bridge:virbr0 \
   --name=rhel6 --os-type linux --os-variant rhel6 \
   --disk path=rhel6.qcow2,format=qcow2,size=10,cache=none \
   --ram 4096 --vcpus=2 --check-cpu --accelerate \
   --hvm --cdrom=rhel-server-6.8-x86_64-dvd.iso

   This launches an instance and starts the installation process.

   Note

   If the instance does not launch automatically, enter the virt-viewer command to view the console:

   [root@host]# virt-viewer rhel6

2. Set up the virtual machines as follows:

   1. At the initial Installer boot menu, select the Install or upgrade an existing system option.
   2. Select the appropriate Language and Keyboard options.
   3. When prompted about which type of devices your installation uses, select Basic Storage Devices.
   4. Select a hostname for your device. The default host name is localhost.localdomain.
   5. Set a root password.
   6. Based on the space on the disk, select the type of installation.
   7. Select the Basic Server install, which includes an SSH server.
3. Reboot the instance and log in as the root user.

4. Update the /etc/sysconfig/network-scripts/ifcfg-eth0 file so it only contains the following values:

   TYPE=Ethernet
   DEVICE=eth0
   ONBOOT=yes
   BOOTPROTO=dhcp
   NM_CONTROLLED=no

5. Restart the service network:

   # service network restart

6. Proceed to Configuring a Host for Registration.

To Configure a Host for Registration:

1. Take note of the fully qualified domain name (FQDN) of the Satellite Server or Capsule Server, for example server.example.com.
2. On the host, connect to a terminal on the host as the root user

3. Install the consumer RPM from the Satellite Server or Capsule Server to which the host is to be registered. The consumer RPM updates the content source location of the host and allows the host to download content from the content source specified in Red Hat Satellite.

   # rpm -Uvh http://server.example.com/pub/katello-ca-consumer-latest.noarch.rpm

To Install the Katello Agent

1. Install the katello-agent RPM package using the following command:

   # yum install katello-agent

2. Ensure goferd is running:

   # systemctl start goferd

1. Install the Puppet agent RPM package using the following command:

   # yum install puppet

2. Configure the puppet agent to start at boot:

   On Red Hat Enterprise Linux 6:

   # chkconfig puppet on

   On Red Hat Enterprise Linux 7:

   # systemctl enable puppet

1. Update the system:

   # {package-update}

2. Install the cloud-init packages:

   # yum install cloud-utils-growpart cloud-init

3. Open the /etc/cloud/cloud.cfg configuration file:

   # vi /etc/cloud/cloud.cfg

4. Under the heading cloud_init_modules, add:

   - resolv-conf

   The resolv-conf option automatically configures the resolv.conf when an instance boots for the first time. This file contains information related to the instance such as nameservers, domain and other options.

5. Open the /etc/sysconfig/network file:

   # vi /etc/sysconfig/network

6. Add the following line to avoid problems accessing the EC2 metadata service:

   NOZEROCONF=yes

7. 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

8. Power off the instance:

   # poweroff

9. On your Red Hat Enterprise Linux Workstation, connect to the terminal as the root user and navigate to the /var/lib/libvirt/images/ directory:

   [root@host]# cd /var/lib/libvirt/images/

10. Reset and clean the image using the virt-sysprep command so it can be used to create instances without issues:

    [root@host]# virt-sysprep -d rhel7

11. 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:

    [root@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.

1. Update the system:

   # {package-update}

2. Install the cloud-init packages:

   # yum install cloud-utils-growpart cloud-init

3. Edit the /etc/cloud/cloud.cfg configuration file and under cloud_init_modules add:

   - resolv-conf

   The resolv-conf option automatically configures the resolv.conf configuration file when an instance boots for the first time. This file contains information related to the instance such as nameservers, domain, and other options.

4. 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).

5. Add the following line to /etc/sysconfig/network to avoid problems accessing the EC2 metadata service:

   NOZEROCONF=yes

6. 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

7. Power off the instance:

   # poweroff

8. 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:

   [root@host]# virt-sysprep -d rhel6

9. 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:

   [root@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.

   Note

   You 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.