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 (using git reference, e.g. tag or commit)
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 the released version of the 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 and the srl-controller is installed onto it, a demo topology with two SR Linux nodes can be deployed as follows:

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

Note, that controller logs can be viewed live with:

kubectl logs --follow -n srlinux-controller $(kubectl get pods -A | grep srlinux-controller | awk '{print $2}')

This will deploy the SR Linux nodes and will create k8s services as per the topology configuration.

SR Linux custom resources can be queried as:

kubectl get srlinux -A

NAMESPACE    NAME   AGE   IMAGE                          STATUS    READY   CONFIG
2-srl-ixr6   srl1   42s   ghcr.io/nokia/srlinux:latest   Running   true    failed
2-srl-ixr6   srl2   42s   ghcr.io/nokia/srlinux:latest   Running   true    loaded

Available statuses:

STATUS: Running when the underlying pod is running. The status is copied from the pod status.
READY: true when the SR Linux node is ready to accept configuration. The status is true when SR Linux management servers is ready to accept connections and configurations.
CONFIG: loaded when the startup-configuration is succesfully applied. The status is failed when errors occured during startup-configuration load.

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 admin@172.19.0.50 command.

Loading images to kind cluster

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

# default kne kind cluster name is `kne`
# which is the last argument in the command

# load locally available container image
kind load docker-image srlinux:0.0.0-38566 --name kne

# load publicly available container image
kind load docker-image ghcr.io/nokia/srlinux:22.6.4 --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:

Checks if the pods exist within a namespace ns with a name r1
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.
When config maps are sorted out, the controller schedules a pod with the name r1 and requeues the request.
If a startup-config was provided, the controller loads this config using SSH into the pod, creates a named checkpoint "initial" and requeues the request.
In a requeue run, the pod is now found and the controller updates the status of Srlinux resource.

Deletion

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

Building `srl-controller` container image

To build srl-controller container image, execute:

# don't forget to set the correct tag
# for example make docker-build IMG=ghcr.io/srl-labs/srl-controller:v0.6.1
make docker-build IMG=ghcr.io/srl-labs/srl-controller:${tag}

build process will try to remove license headers for some manifests, discard those changes.

Next, update the controller version in manager/kustomization.yaml kustomization file to match the newly built version.

Finally, upload the container image to the registry:

docker push ghcr.io/srl-labs/srl-controller:${tag}

# if this is the latest version, also push it with the `latest` tag
docker tag ghcr.io/srl-labs/srl-controller:${tag} ghcr.io/srl-labs/srl-controller:latest
docker push ghcr.io/srl-labs/srl-controller:latest

Note, update the SR Linux manifest in the KNE repo to use the new version of the controller. To generate the manifest, run:

kustomize build config/default

Developers guide

Developers should deploy the controller onto a cluster from the source code. Ensure that the srl-controller is uninstalled from the cluster before proceeding.

The cluster should be deployed with the kne cli utility. First, make sure to remove the controller section from kne's kind-bridge.yaml file so that controllers are not installed automatically, as we will install srl-controller from the source code.

kne deploy deploy/kne/kind-bridge.yaml

Install the Srlinux CRDs onto the cluster

make install

To build and run the controller from the source code:

make run

Controller's log printed to stdout/stderr. It is possible to deploy topologies with kne create now.

Make changes to the controller code-base, and re-run make run to see the changes in effect.

srl-labs/srl-controller