srl-controller

SR Linux Controller for KNE

This is a k8s controller for running and managing SR Linux nodes launched from openconfig/kne topology.

Install

To install the latest version of this controller on a cluster referenced in ~/.kube/config issue the following command:

# latest version
kubectl apply -k https://github.com/srl-labs/srl-controller/config/default

# specific version
kubectl apply -k https://github.com/srl-labs/srl-controller/config/default?ref=v0.3.1

The resources of this controller will be scoped under srlinux-controller namespace.

❯ kubectl get all -n srlinux-controller

NAME                                                        READY   STATUS    RESTARTS   AGE
pod/srlinux-controller-controller-manager-c7495dcc7-rbh7m   2/2     Running   0          6m5s

NAME                                                            TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)    AGE
service/srlinux-controller-controller-manager-metrics-service   ClusterIP   10.96.34.86   <none>        8443/TCP   16m

NAME                                                    READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/srlinux-controller-controller-manager   1/1     1            1           16m

NAME                                                              DESIRED   CURRENT   READY   AGE
replicaset.apps/srlinux-controller-controller-manager-c7495dcc7   1         1         1       16m

Installing from a repo

The controller can be installed with make directly from the repo:

make deploy IMG=ghcr.io/srl-labs/srl-controller:0.3.1

Make sure to check which controller versions are available.

Uninstall

To uninstall the controller from the cluster:

kubectl delete -k https://github.com/srl-labs/srl-controller/config/default

Testing with kne & kind

To run this controller in a test cluster deployed with kne and kind follow the steps outlined in the KNE repository.

Once the kne+kind cluster is created, a demo topology with two SR Linux nodes may be deployed as follows:

kne create examples/srlinux/2node-srl-with-config.pbtxt

This will deploy the SR Linux nodes and will create k8s services as per the topology configuration. The services will be exposed via MetalLB and can be queried as:

❯ kubectl -n 3node-srlinux get svc
NAME         TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)                                      AGE
service-r1   LoadBalancer   10.96.151.84    172.19.0.50   57400:30006/TCP,443:30004/TCP,22:30005/TCP   6m10s
service-r2   LoadBalancer   10.96.34.36     172.19.0.51   443:30010/TCP,22:30011/TCP,57400:30009/TCP   6m9s

To connect with SSH to the r1 node, use ssh [email protected] command.

Loading images to kind cluster

Public SR Linux container image will be pulled by kind automatically, if Internet access is present. Images which are not available publicy can be uploaded to kind manually:

# default kne kind cluster name is `kne`
# which is the last argument in the command
kind load docker-image srlinux:0.0.0-38566 --name kne

Using license files

To remove the packets-per-second limit of a public container image or to launch chassis-based variants of SR Linux (ixr-6e/10e) KNE users should provide a valid license file to the srl-controller.

Navigate to Using license files document to have a detailed explanation on that topic.

Controller operations

The controller is designed to manage the Srlinux custom resource defined with the following CRD.

The request to create/delete a resource of kind Srlinux is typically coming from openconfig/kne topology.

Creation

When a request to create a Srlinux resource named r1 in namespace ns comes in, the controller's reconcile loop does the following:

1. Checks if the pods exist within a namespace ns with a name r1
2. If the pod hasn't been found, then the controller first ensures that the necessary config maps exist in namespace ns and creates them otherwise.
3. When config maps are sorted out, the controller schedules a pod with the name r1 and requeue the request
4. In a requeue run, the pod is now found and the controller updates the status of Srlinux resource with the image name that was used in the pod spec.

Deletion

When a deletion happens on Srlinux resource, the reconcile loop does nothing.

API access

This repo contains a clientset for API access to the Srlinux custom resource. Check kne repo to see how this can be done.

Building srl-controller container image

To build srl-controller container image execute:

# don't forget to set the correct tag
make docker-build IMG=ghcr.io/srl-labs/srl-controller:${tag}

Then upload the image to the registry and update the controller version in manager/kustomization.yaml.