watcher-agent

README

WARNING: This repository is published by the Nephio Authors but is neither endorsed nor maintained by the Nephio Technical Steering Committee (TSC). It is intended to be used for reference only. The Nephio distribution repositories are located in the nephio-project organization. For more information see this page.

watcheragent

Watcheragent runs on workload clusters, watches resources on the cluster based on requests, and reports back to a designated gRPC server on any resource status changes.

Description

WatcherAgent runs on workload clusters (installation of watcheragent at this point is manual), it watches the WatcherAgent CR, which gives information on the gRPC server to connect to and the resources to watch for. WatcherAgent would then create gRPC client to connect to the gRPC server specified by the CR, and starts to report status fields as requested by the WatcherAgent CR.

WatcherAgent periodically fetches the statuses of the target resources on the workload cluster, and tracks if the status values have changed, and only posts updates to these statuses to the gRPC server configured if there is any changes to those statuses under monitoring.

Getting Started

You’ll need a Kubernetes cluster to run against. You can use KIND to get a local cluster for testing, or run against a remote cluster. Note: Your controller will automatically use the current context in your kubeconfig file (i.e. whatever cluster kubectl cluster-info shows).

Running on the cluster

1. Install Instances of Custom Resources:

make install

1. Build and push your image to the location specified by IMG:

make docker-build docker-push IMG=<some-registry>/watcheragent:tag

1. Deploy the controller to the cluster with the image specified by IMG:

make deploy IMG=<some-registry>/watcheragent:tag

Uninstall CRDs

To delete the CRDs from the cluster:

make uninstall

Undeploy controller

UnDeploy the controller to the cluster:

make undeploy

How it works

This project aims to follow the Kubernetes Operator pattern

It uses Controllers which provides a reconcile function responsible for synchronizing resources untile the desired state is reached on the cluster

Test It Out

1. Install the CRDs into the cluster:

make install

1. Run your controller (this will run in the foreground, so switch to a new terminal if you want to leave it running):

make run

NOTE: You can also run this in one step by running: make install run

Modifying the API definitions

If you are editing the API definitions, generate the manifests such as CRs or CRDs using:

make manifests

NOTE: Run make --help for more information on all potential make targets

More information can be found via the Kubebuilder Documentation