obassett/trident_mcc

trident_mcc

Table of Contents

• trident_mcc
  • Table of Contents
  • Background
    • What is Trident?
    • What is Metrocluster?
  • Purpose
    • How does trident_mcc resolve this?
  • Installation
    • All in One YAML deployment
    • Environment Variables
  • Issues and Contributions

Background

This project atte***s to resolve a current issue when using NetApp Trident with NetApp Metrocluster. The issue occurs when the Metrocluster fails-over. At the point of the fail-over, although all the data volumes continue to function the ability for Trident to manage the volume life-cycles - provisioning, deleting, updating.

What is Trident?

From the https://netapp-trident.readthedocs.io/:

Trident is a fully supported open source project maintained by NetApp. It has been designed from the ground up to help you meet your containerized applications’ persistence demands using industry-standard interfaces, such as the Container Storage Interface (CSI).

Trident deploys in Kubernetes clusters as pods and provides dynamic storage orchestration services for your Kubernetes workloads. It enables your containerized applications to quickly and easily consume persistent storage from NetApp’s broad portfolio that includes ONTAP (AFF/FAS/Select/Cloud), Element software (HCI/SolidFire), and SANtricity (E/EF-Series) data management software, as well as the Azure NetApp Files service, Cloud Volumes Service on Google Cloud, and the Cloud Volumes Service on AWS.

What is Metrocluster?

From the https://www.netapp.com/support-and-training/documentation/metrocluster/:

NetApp® MetroCluster™ configurations com***e array-based clustering with synchronous replication to deliver continuous availability, immediately duplicating all of your mission-critical data on a transaction-by-transaction basis. MetroCluster configurations enhance the built-in high availability and nondisruptive operations of NetApp hardware and ONTAP® storage software, providing an additional layer of protection for the entire storage and host environment.

Purpose

Currently when using Trident with Metrocluster configurations, if the Storage Virtual Machine (SVM) fails over to the other nodes in the Metrocluster the SVM name changes, when this happens Trident is no longer able to manage volumes on this SVM. Though underlying storage access to these volumes continues correctly.

How does trident_mcc resolve this?

This project deploys as a kubernetes pod alongside trident in the trident namespace. At a set polling interval it queries the kubernertes API for all the TridentBackendConfig objects, and then connects to the backend to validate the SVM name in the TridentBackendConfiguration matches the actual SVM name, if it doesn't it updates the TridentBackendConfiguration.

Note: The first time trident_mcc runs on a given TridentBackendConfig - if no SVM configuration is specified then it will add one based on the current SVM name when it queries the backend.

Installation

The trident_mcc project requires permissions to the following resources:

• Cluster Scoped:
  • namespaces - GET and LIST - To validate the trident namespace
• Namespace Scoped:
  • secrets - GET, HEAD, and LIST - To get the credentials for the backend storage
  • tridentbackendconfigs.trident.netapp.io - GET, HEAD, PATCH and LIST - To get and modify the Trident Backend Configuration

All in One YAML deployment

If your trident installation uses the trident namespace (by default) then you can run the following to install trident_mcc:

kubectl apply -f https://github.com/obassett/trident_mcc/raw/main/deployment/trident-mcc-full-deployment.yaml

This will create the service account, roles. ***dings and then finally the deployment.

If you are not using the default 'trident' namespace, then you can download this file and update with the correct namespace

Environment Variables

Inside of the deployment there are several environment variables you can set to affect the code.

Issues and Contributions

Please feel free to create github issues and pull requests.