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nanometal/k8s-concept-review.org

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+#+TITLE: K8s concepts review
+#+AUTHOR: Adam Mohammed
+#+DATE: September 18, 2023
+
+
+At one of the meetings I brought up how similar nano-metal felt to a
+collection of K8s specifications that make standing up and managing
+K8s clusters easier. In this document I'll cover the following topics
+at a high level: Cluster API, CNI, CCM, and CSI.
+
+First is the Cluster API, this came about as a means for creating and
+managing kubernetes clusters using kubernetes it self. The cluster API
+allows an operator to use a so-called "management cluster" to create
+other K8s clusters known as "Workload clusters." The cluster API is
+NOT part of the core K8s resources, but is implemented as a set of
+custom resource definitions and controllers to actually carry out the
+desired actions.
+
+A cluster operator can use the cluster-api to create workload clusters
+by relying on 3 components: bootstrap provider, infrastructure
+provider, and the control plane provider. Nanometal aims at making
+provisioning of bare metal machines extensible and scalable by
+enabling facilities to carry out the desired operations requested by
+the EMAPI. We can think of the EMAPI as the "management cluster" in
+this world.
+
+What Metal has today, maps well to the infrastructure provider, since
+all the cluster-api has to do is ask for machines with a certain
+configuration and the provider is responsible for making that
+happen. I think for this project a bulk of this work is figuring out
+how we make the infrastructure provider out of our existing
+components, but let's put that aside for right now and consider the
+rest of the components.
+
+The bootstrap and the control plane providers are concepts that also
+seem important to our goal. We want it to be simple for us to enter a
+new facility and set up the components we need to start provisioning
+hardware. The bootstrap provider, in the cluster-api concepts turns a
+server provisioned with a base OS into an operating K8s node. For us,
+we probably would also want some process which turns any facility or
+existing datacenter, into an equinix metal managed facility.
+
+Once we know about the facility that we need to manage, the concept of
+the control plane provider maps well with the diagrams from Nanometal
+so far. We'd want some component that installs the required agent and
+supporting components in the facilty so we can start to be able to
+provide metal services there.