CSI-Addons for Kubernetes

This repository contains the implementation for the CSI-Addons specification that can be used with Kubernetes.

The CSI API is tightly integrated with Kubernetes. In order to extend the interface, a new CSI-Addons Controller is needed. The CSI-Addons Controller will watch for Kubernetes events (CRs) and relay operation initiated by the user to the CSI-driver.

.------.   CR  .------------.
| User |-------| CSI-Addons |
'------'       | Controller |
               '------------'
                      |
                      | gRPC
                      |
            .---------+------------------------------.
            |         |                              |
            |  .------------.        .------------.  |
            |  | CSI-Addons |  gRPC  |    CSI     |  |
            |  |  side-car  |--------| Controller |  |
            |  '------------'        | NodePlugin |  |
            |                        '------------'  |
            | CSI-driver Pod                         |
            '----------------------------------------'

A CSI-Addons side-car will be running in the CSI-driver (provisioner and node-plugin) Pods. The side-car calls gRPC procedures for CSI-Addons operations.

CSI-driver side-car

The CSI-driver side-car is located with the CSI-Controller (provisioner) and the CSI-nodeplugin containers. The side-car registers itself by creating a CSIAddonsNode CR that the CSI-Addons Controller can use to connect to the side-car and execute operations.

csi-addons executable

The csi-addons executable can be used to call CSI-Addons operations against a CSI-driver. It is included in the side-car container image, so that manual execution by admins and (automated) testing can easily be done.

See the csi-addons tool documentation for more details.

Controller

The CSI-Addons Controller handles the requests from users to initiate an operation. Users create a CR that the controller inspects, and forwards a request to one or more CSI-Addons side-cars for execution.

By listing the CSIAddonsNode CRs, the CSI-Addons Controller knows how to connect to the side-cars. By checking the supported capabilities of the side-cars, it can decide where to execute operations that the user requested.

Installation by operator

A CSI-Addons bundle can be used to install the CSI-Addons Controller with the following steps:

$ kubectl create namespace storage-csi-addons
$ make operator-sdk
$ ./bin/operator-sdk run bundle -n storage-csi-addons quay.io/csiaddons/k8s-bundle:latest

In the future, the bundle is expected to become available in the OperatorHub.

Installation with kustomize

This project uses kustomize and a Makefile for deploying. By running the command

$ make deploy
...
customresourcedefinition.apiextensions.k8s.io/csiaddonsnodes.csiaddons.openshift.io created
customresourcedefinition.apiextensions.k8s.io/reclaimspacejobs.csiaddons.openshift.io created
serviceaccount/csi-addons-controller-manager created
role.rbac.authorization.k8s.io/csi-addons-leader-election-role created
clusterrole.rbac.authorization.k8s.io/csi-addons-manager-role created
clusterrole.rbac.authorization.k8s.io/csi-addons-metrics-reader created
clusterrole.rbac.authorization.k8s.io/csi-addons-proxy-role created
rolebinding.rbac.authorization.k8s.io/csi-addons-leader-election-rolebinding created
clusterrolebinding.rbac.authorization.k8s.io/csi-addons-manager-rolebinding created
clusterrolebinding.rbac.authorization.k8s.io/csi-addons-proxy-rolebinding created
configmap/csi-addons-manager-config created
service/csi-addons-controller-manager-metrics-service created
deployment.apps/csi-addons-controller-manager created

the different components for the Controller will get deployed in the csi-addons-system Namespace.

$ kubectl -n csi-addons-system get all
NAME                                                 READY   STATUS    RESTARTS   AGE
pod/csi-addons-controller-manager-687d47b8c7-9m56f   2/2     Running   0          49s

NAME                                                    TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE
service/csi-addons-controller-manager-metrics-service   ClusterIP   172.30.153.17   <none>        8443/TCP   49s

NAME                                            READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/csi-addons-controller-manager   1/1     1            1           49s

NAME                                                       DESIRED   CURRENT   READY   AGE
replicaset.apps/csi-addons-controller-manager-687d47b8c7   1         1         1       49s

Contributing

The Contribution Guidelines contain details on the process to contribute to this project.

For feature enhancements, or questions about particular features or design choices, there is a mailinglist. All regular contributors are encouraged to subscribe to the list, and participate in the discussions.

Subscribing can be done through the mailman web interface or by sending an email to [email protected] with subject subscribe.