As user ansible (unless otherwise specified), prepare and run the Ansible playbooks.

Note: Ensure that the CSAH node can reach the iDRAC network IPs. If there is no connectivity, manually create the inventory file by following the steps in the sample file in GitHub.

1. Update a YAML file containing information about bootstrap, control-plane, and compute nodes.

Note: Ensure that only values in the YAML file are modified. Keys must always remain the same.

• For bootstrap, which is created as a kernel-based virtual machine (KVM), specify only the operating system IP address.
• For control plane nodes, specify both the operating system and iDRAC IP address.
• For compute nodes, specify the operating system also. This information is necessary because compute nodes support Red Hat Enterprise Linux 7.9 and RHCOS 4.6. The supported value for the ‘os’ key is either rhcos or rhel.

2. Run the Python scripts in the <git clone directory>/python directory to create an inventory file automatically for Ansible playbooks:

[ansible@csah python]$ python3 generate_inventory_file.py

usage: generate_inventory_file.py [-h] [--run | --add] --ver {4.6} --nodes NODES [--id_user ID_USER] [--id_pass ID_PASS] [--debug]

Generate Inventory

optional arguments:

  -h, --help         show this help message and exit

  --run              generate inventory file

  --add              number of compute nodes

  --ver {4.6}        specify OpenShift version

  --nodes NODES      nodes inventory file

  --id_user ID_USER  specify idrac user

  --id_pass ID_PASS  specify idrac user

  --debug            specify debug logs

Note: If the iDRAC user and password are the same across all control-plane and compute nodes, run the program with arguments --id_user and --id_pass.

3. Run the program:

[ansible@csah python]$ python3 generate_inventory_file.py

–-run --id_user <user> --id_pass <password> --ver 4.6 –-nodes nodes.yaml

Note: In the argument that is passed, --ver 4.6 specifies the OpenShift version. Currently, the script accepts only one value: 4.6. The nodes.yaml file that you updated in Step 1 includes information about the bootstrap, control-plane, and compute nodes.

A list of numbered tasks is displayed, as shown in the following figure:

Figure 2.    Inventory file generation input tasks menu

4. Select the number of each task in turn and provide the requested input.

Note: If you are unsure about what value to enter for an option, accept the default value if it is provided.

1. For option 1, specify the directory to which to download the files:

provide complete path of directory to download OCP 4.6 software bits

default [/home/ansible/files]:

Option 1 downloads OpenShift Container Platform 4.6 software from Red Hat into a directory for which user ansible has permissions. This guide assumes that the directory is specified as /home/ansible/files.

2. For option 2:

i             Enter the cluster installation options by selecting 3 node or 6+ node:

task choice for necessary inputs: 2

supported cluster install options:

        1. 3 node (control/compute in control nodes)

        2. 6+ node (3 control and 3+ compute)

enter cluster install option: 2

Note: OpenShift 4.6 supports the 3 node and 6+ node cluster options. The following example shows the steps to follow if you select a 6+ node cluster installation. If you select the 3 node installation option, you are not prompted for information about compute nodes.

ii           Specify the bootstrap node name and the IP address to be assigned to the bootstrap node:

enter the bootstrap node name

default [bootstrap]:

ip address for os in bootstrap node: 192.168.46.19

Note: Leave the IP address 192.168.42.19 that you specified in the preceding step unassigned. The bootstrap node is created as a KVM using virt-install.

iii          Specify the number of control-plane nodes in the cluster and provide additional details as appropriate.

Note: The following example assumes that three control-plane nodes are set up in the cluster. NIC.Slot.2-1-1 is used for DHCP, and PXE boot is enabled in the interface. Bonding is performed through two interfaces: NIC.Slot.2-1-1 and NIC.Slot.2-2-1. If only one interface is available, specify NO.

Do you want to perform bonding (y/NO): y

ip address for os in etcd-0 node: 192.168.46.21

ip address for idrac in etcd-0 node: 192.168.34.21

1 -> NIC.Integrated.1-1-1

2 -> NIC.Integrated.1-2-1

3 -> NIC.Slot.2-1-1

4 -> NIC.Slot.2-2-1

Select the interface used by DHCP: 3

selected interface is: NIC.Slot.2-1-1

device NIC.Slot.2-1-1 mac address is B8:59:9F:C0:36:46

1 -> NIC.Integrated.1-1-1

2 -> NIC.Integrated.1-2-1

3 -> NIC.Slot.2-1-1

4 -> NIC.Slot.2-2-1

Select the interface used by etcd-0 active bond interface: 3

selected interface is: NIC.Slot.2-1-1

1 -> NIC.Integrated.1-1-1

2 -> NIC.Integrated.1-2-1

3 -> NIC.Slot.2-1-1

4 -> NIC.Slot.2-2-1

Select the interface used by etcd-0 backup bond interface: 4

selected interface is: NIC.Slot.2-2-1

Note: The selected network interface determines the calculation for network enumeration ens2fo. This network enumeration logic is tested in PowerEdge R640 servers. Select two interfaces, one for each “slave” interface in bond.

3. Repeat the preceding step for the remaining control-plane nodes.
4. After you have entered the control-plane node information, provide the compute node information by entering the default number of compute nodes.

Note:
This step is not necessary if you selected 3 node in Step 4, substep b.i. The compute node supports either Red Hat Enterprise Linux 7.9 or RHCOS 4.6 as the operating system.

Specify information relating to bonding and the interfaces that bonding uses for each compute node (see Step 4, substep b.iii for control-plane nodes).

5. For option 3, provide details about the disks that are used in control-plane and compute nodes:

ensure disknames are absolutely available. Otherwise OpenShift install fails

specify the control plane device that will be installed

default [nvme0n1]:

specify the compute node device that will be installed

default [nvme0n1]:

Note: This guide assumes that the NVMe drive in the first slot is used for the OpenShift installation.

6. For option 4, provide the cluster name and the DNS zone file name:

specify cluster name

default [ocp]:

specify zone file

default [/var/named/ocp.zones]:

7. For option 5, provide details for the HTTP web server setup and directory names that are created under /var/www/html:

enter http port

default [8080]:

specify dir where ignition files will be placed

directory will be created under /var/www/html

default [ignition]:

8. For option 6, provide details about the default user that is used to install the OpenShift Container Platform cluster, the service network CIDR, pod network CIDR, and other information to be added in the install-config.yaml file:

enter the user used to install openshift

DONOT CHANGE THIS VALUE

default [core]:

enter the directory where openshift installs

directory will be created under /home/core

default [openshift]:

enter the pod network cidr

default [10.128.0.0/14]:

pod network cidr: 10.128.0.0/14

specify cidr notation for number of ips in each node:

cidr number should be an integer and less than 32

default [23]:

specify the service network cidr

default [172.30.0.0/16]:

Note: Do not change the user value from core. Only the core user can connect into cluster nodes by using SSH. The CNI options are the specified information.

9. Select option 7 to print the inputs that you have provided.

To modify any values, run the related option again and correct the values.

10. Select option 8 to perform a YAML dump of all the displayed contents into the generated_inventory file in the current directory (see this sample file in GitHub for guidance).

5. Download Red Hat Enterprise Linux 7.9 nodes from the Red Hat Customer Portal to install on the compute nodes. (Red Hat account credentials are required.)
6. Log in to Red Hat to download the pullsecret file (Red Hat account credentials are required). Copy the file contents into the pullsecret file in the directory containing the OpenShift Container Platform 4.6 software bits.

Note: This guide uses the /home/ansible/files directory containing the software bits.

7. In the generated_inventory file, add the following content under the software_src key, and then save the file:

vars:

  software_src: /home/ansible/files

  pull_secret_file: pullsecret

  rhel_os: rhel-server-7.9-x86_64-dvd.iso

Note: Copy the generated_inventory file from the <git clone dir>/python/ directory to <git clone dir>/ansible directory.

8. As user ansible, run the playbooks:

[ansible@csah ansible] $ pwd

/home/ansible/openshift-bare-metal/ansible

[ansible@csah ansible] $ ansible-playbook -i generated_inventory ocp.yaml

The CSAH node is installed and configured with HTTP, HAProxy, DHCP, DNS, and PXE services. Also, the install-config.yaml file is generated, and the ignition config files are created and made available over HTTP.

Note: If any errors occur while the program is running, see the inventory.log file under the <git clone dir>/python directory to find out what went wrong and how to resolve the issue.