openstack-ansible-ops/mcapi_vexxhost/README.rst

Install vexxhost magnum-cluster-api driver

About this repository

This repository includes playbooks and roles to deploy the Vexxhost magnum-cluster-api driver for the OpenStack Magnum service.

The playbooks create a complete deployment including the control plane k8s cluster which should result in a ready-to-go experience for operators.

The following architectural features are present:

• The control plane k8s cluster is an integral part of the openstack-ansible deployment, and forms part of the foundational components alongside mariadb and rabbitmq.
• The control plane k8s cluster is deployed on the infra hosts and integrated with the haproxy loadbalancer and OpenStack internal API endpoint, and not exposed outside of the deployment
• SSL is supported between all components and configuration is possible to support different certificate authorities on the internal and external loadbalancer endpoints.
• Control plane traffic can stay entirely within the management network if required
• The magnum-cluster-api-proxy service is deployed to allow communication between the control plane and workload clusters when a floating IP is not attached to the workload cluster.
• It is possible to do a completely offline install for airgapped environments

The magnum-cluster-api driver for magnum can be found here https://github.com/vexxhost/magnum-cluster-api

Documentation for the Vexxhost magnum-cluster-api driver is here https://vexxhost.github.io/magnum-cluster-api/

The ansible collection used to deploy the controlplane k8s cluster is here https://github.com/vexxhost/ansible-collection-kubernetes

The ansible collection used to deploy the container runtime for the controlplane k8s cluster is here https://github.com/vexxhost/ansible-collection-containers

These playbooks require Openstack-Ansible Caracal or later.

Highlevel overview of the Magnum infrastructure these playbooks will build and operate against.

Pre-requisites

• An existing openstack-ansible deployment
• Control plane using LXC containers, bare metal deployment is not tested
• Core openstack services plus Octavia

OpenStack-Ansible Integration

The playbooks are distributed as an ansible collection, and integrate with Openstack-Ansible by adding the collection to the deployment host by adding the following to /etc/openstack_deploy/user-collection-requirements.yml under the collections key.

../../mcapi_vexxhost/playbooks/files/openstack_deploy/user-collection-requirements.yml

The collections can then be installed with the following command:

cd /opt/openstack-ansible
openstack-ansible scripts/get-ansible-collection-requirements.yml

The modules in the kubernetes collection require an additional python module to be present in the ansible-runtime python virtual environment. Specify this in /etc/openstack_deploy/user-ansible-venv-requirements.txt

../../mcapi_vexxhost/playbooks/files/openstack_deploy/user-ansible-venv-requirements.txt

OpenStack-Ansible configuration for magnum-cluster-api driver

Specify the deployment of the control plane k8s cluster in /etc/openstack_deploy/env.d/k8s.yml

../../mcapi_vexxhost/playbooks/files/openstack_deploy/env.d/k8s.yml

Define the physical hosts that will host the controlplane k8s cluster in /etc/openstack_deploy/conf.d/k8s.yml. This example is for an all-in-one deployment and should be adjusted to match a real deployment with multiple hosts if high availability is required.

../../mcapi_vexxhost/playbooks/files/openstack_deploy/conf.d/k8s.yml

Integrate the control plane k8s cluster with the haproxy loadbalancer in /etc/openstack_deploy/group_vars/k8s_all/haproxy_service.yml

../../mcapi_vexxhost/playbooks/files/openstack_deploy/group_vars/k8s_all/haproxy_service.yml

Configure the LXC container that will host the control plane k8s cluster to be suitable for running nested containers in /etc/openstack_deploy/group_vars/k8s_all/main.yml

There you can also set config-overrides for the control plane of the k8s cluster, which integrate the control plane k8s deployment with the rest of the openstack-ansible deployment.

../../mcapi_vexxhost/playbooks/files/openstack_deploy/group_vars/k8s_all/main.yml

Set up config-overrides for the magnum service in /etc/openstack_deploy/group_vars/magnum_all/main.yml. Adjust the images and flavors here as necessary, these are just for demonstration. Upload as many images as you need for the different workload cluster kubernetes versions.

Attention must be given to the SSL configuration. Users and workload clusters will interact with the external endpoint and must trust the SSL certificate. The magnum service and cluster-api can be configured to interact with either the external or internal endpoint and must trust the SSL certificiate. Depending on the environment, these may be derived from different certificate authorities.

../../mcapi_vexxhost/playbooks/files/openstack_deploy/group_vars/magnum_all/main.yml

Run the deployment

For a new deployment

Run the OSA playbooks/setup.yml playbooks as usual, following the normal deployment guide.

Run the magnum-cluster-api deployment

openstack-ansible osa_ops.mcapi_vexxhost.k8s_install

For an existing deployment

Ensure that the python modules required for ansible are present:

./scripts/bootstrap-ansible.sh

Alternatively, without re-running the bootstrap script:

/opt/ansible-runtime/bin/pip install docker-image-py

Add the magnum-cluser-api driver to the magnum service

openstack-ansible playbooks/os-magnum-install.yml

Create the k8s control plane containers

openstack-ansible playbooks/lxc-containers-create.yml --limit k8s_all

Run the magnum-cluster-api deployment

openstack-ansible osa_ops.mcapi_vexxhost.k8s_install

Optionally run a functional test of magnum-cluster-api

This can be done quickly using the following playbook

openstack-ansible osa_ops.mcapi_vexxhost.functional_test

This playbook will create a neutron public network, download a prebuilt k8s glance image, create a nova flavor and a magnum cluster template.

It will then deploy the workload k8s cluster using magnum, and run a sonobouy "quick mode" test of the workload cluster.

This playbook is intended to be used on an openstack-ansible all-in-one deployment.

Use Magnum to create a workload cluster

Upload Images

Create a cluster template

Create a workload cluster

Optional Components

Deploy the workload clusters with a local registry

TODO - describe how to do this

Deploy the control plane cluster from a local registry

TODO - describe how to do this

Use of magnum-cluster-api-proxy

TODO - describe what this is for

Troubleshooting

Local testing

An OpenStack-Ansible all-in-one configured with Magnum and Octavia is capable of running a functioning magnum-cluster-api deployment.

Sufficient memory should be available beyond the minimum 8G usually required for an all-in-one. A multinode workload cluster may require nova to boot several Ubuntu images in addition to an Octavia loadbalancer instance. 64G would be an appropriate amount of system RAM.

There also must be sufficient disk space in /var/lib/nova/instances to support the required number of instances - the normal minimum of 60G required for an all-in-one deployment will be insufficient, 500G would be plenty.