DCI OpenShift Agent on libvirt

Table of contents

If you are interested in getting an OCP deployment running as quickly as possible you will find in the /samples/ocp_on_libvirt folder some configuration examples to run the DCI Openshift Agent in a “all-in-one” full virtualized environment.

In this case, the agent will use libvirt virtual machines deployed on top of the DCI Jumpbox.

Please note that systems are nested virtual machines at least in the case of the provision host: provisioner will spawn a bootstrap VM inside itself, in our case that would be a VM inside a VM. Please remember to enable nested_kvm in your Jumpbox.

The full virtualized environment scenario requires the DCI Jumpbox to have at least 64 Gi of memory and 200 Gi of storage to host a virtual provision machine and all virtual masters.

The provided example will create 4 systems (1 provisionner and 3 OCP masters) on top of the DCI Jumpbox. The number of nodes can be adapted by modifying the samples/ocp_on_libvirt/inventory/libvirt_resources.yml file.

How to run the fully virtualized example

This example will help you to run the dci-openshift-agent within one single system by running libvirt virtual machines. This example is a good path to understand the dci-openshift-agent (all different steps, hooks, settings) and to be used as a development environment.

At this point, the DCI Jumpbox is installed with all above prerequisites (learn how to install the DCI Jumpbox).

The following documentation covers how to configure deploy virtual systems, virtual networks and the according /etc/dci-openshift-agent/hooks/ configuration.

It will also guide you to generate and use an appropriate settings file for this scenario.

Please note, that in the fully virtualized environment, the DCI Openshift Agent will create the Openshift Provisioning node system automatically.

First, you need to work directly as the dci-openshift-agent user:

# su - dci-openshift-agent
$ id
uid=990(dci-openshift-agent) gid=987(dci-openshift-agent) groups=987(dci-openshift-agent),107(qemu),985(libvirt) ...

Run libvirt_up playbook to configure libvirt nodes. This playbook will:

  • Create 3 local virtual machines to be used as System Under Test
  • Create 1 local virtual machine to be used as a Provisioning node
  • Generate the relative hosts file (ready to be used as an inventory for the dci-openshift-agent).
  • Provide a pre-run.yml hook file to be used by the agent.
cd ~/samples/ocp_on_libvirt/
$ ansible-playbook -v libvirt_up.yml

Copy the newly created file hosts to the /etc/dci-openshift-agent directory:

$ pwd
~/samples/ocp_on_libvirt
$ sudo cp hosts /etc/dci-openshift-agent/

The dci-openshift-agent is now ready to run the “all-in-one” virtualized workflow.

You can check the virtual machines status by using virsh command:

$ sudo virsh list --all
 Id    Name                           State
----------------------------------------------------
 60    provisionhost                  running
 64    master-0                       off
 65    master-2                       off
 66    master-1                       off

From here on out you can run your agent normally as you would with baremetal hardware, please refer to the main README.md file section "Starting the DCI OCP Agent" for how to start the agent. The agent will see the virtualized resources as regular resources thanks to SSH and VBMC emulation.

After you run a DCI job (see the main README.md) you will be able to interact with the RHOCP cluster:

$ export KUBECONFIG=/home/admin/clusterconfigs/auth/kubeconfig
$ oc get pods --all-namespaces

In case you need to delete the fully virtualized environment, you can run the playbook libvirt_destroy.yml:

$ cd samples/ocp_on_libvirt/
$ ansible-playbook -v libvirt_destroy.yml

Demo screencast

demo

Additional resources

We have provided dnsmasq config templates in the samples directory to serve dhcp/dns from the dci jumpbox if you don’t already have a dns/dhcp server on your bare metal network.

Troubleshooting

The kni page offers a good start to understand and debug your libvirt environments.

Furthermore, some issues (see below) are specific to a libvirt(or small) environment.

Installer Timeout

Due to the lack of hardware (cpu, memory) and the fact that all resources are virtualized, the installation may take longer to complete. A recurring timeout is reached during the bootstrap.

Two parameters are available to increase this timeout, increase_bootstrap_timeout and increase_install_timeout.

- name: "installer : Run IPI installer"
  import_role:
    name: installer
  vars:
    increase_bootstrap_timeout: 2
    increase_install_timeout: 2

If you need to troubleshoot this environment for bootstrap/install issues please follow the "Troubleshooting" section(s) in the main README

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