iPerf3

Running basic connectivity between iPerf3 applications across two sites using ClusterLink.

In this tutorial we’ll establish iPerf3 connectivity between two kind cluster using ClusterLink. The tutorial uses two kind clusters:

  1. Client cluster - runs ClusterLink along with an iPerf3 client.
  2. Server cluster - runs ClusterLink along with an iPerf3 server.
  1. Install ClusterLink CLI on Linux or Mac using the installation script:

    curl -L https://github.com/clusterlink-net/clusterlink/releases/latest/download/clusterlink.sh | sh -
    
  2. Verify the installation:

    clusterlink --version
    

Initialize clusters

In this tutorial we set up a local environment using kind. You can skip this step if you already have access to existing clusters, just be sure to set KUBECONFIG accordingly.

To setup two kind clusters:

  1. Install kind using kind installation guide.

  2. Create a directory for all the tutorial files:

    mkdir iperf3-tutorial
    
  3. Open two terminals in the tutorial directory and create a kind cluster in each terminal:

    Client cluster:

    cd iperf3-tutorial
    kind create cluster --name=client
    

    Server cluster:

    cd iperf3-tutorial
    kind create cluster --name=server
    

    Note

    kind uses the prefix kind, so the name of created clusters will be kind-client and kind-server.

  4. Setup KUBECONFIG on each terminal to access the cluster:

    Client cluster:

    kubectl config use-context kind-client
    cp ~/.kube/config $PWD/config-client
    export KUBECONFIG=$PWD/config-client
    

    Server cluster:

    kubectl config use-context kind-server
    cp ~/.kube/config $PWD/config-server
    export KUBECONFIG=$PWD/config-server
    

Tip

You can run the tutorial in a single terminal and switch access between the clusters using kubectl config use-context kind-client and kubectl config use-context kind-server.

Deploy iPerf3 client and server

Install iPerf3 (client and server) on the clusters:

Client cluster:

export IPERF3_FILES=https://raw.githubusercontent.com/clusterlink-net/clusterlink/main/demos/iperf3/testdata/manifests
kubectl apply -f $IPERF3_FILES/iperf3-client/iperf3-client.yaml

Server cluster:

export IPERF3_FILES=https://raw.githubusercontent.com/clusterlink-net/clusterlink/main/demos/iperf3/testdata/manifests
kubectl apply -f $IPERF3_FILES/iperf3-server/iperf3.yaml
  1. Create the fabric and peer certificates for the clusters:

    Client cluster:

    clusterlink create fabric
    clusterlink create peer-cert --name client
    

    Server cluster:

    clusterlink create peer-cert --name server
    

    For more details regarding fabric and peer see core concepts.

  2. Deploy ClusterLink on each cluster:

    Client cluster:

    clusterlink deploy peer --name client --ingress=NodePort --ingress-port=30443
    

    Server cluster:

    clusterlink deploy peer --name server --ingress=NodePort --ingress-port=30443
    

    Note

    This tutorial uses NodePort to create an external access point for the kind clusters. By default deploy peer creates an ingress of type LoadBalancer, which is more suitable for Kubernetes clusters running in the cloud.

  3. Verify that ClusterLink control and data plane components are running:

    It may take a few seconds for the deployments to be successfully created.

    Client cluster:

    kubectl rollout status deployment cl-controlplane -n clusterlink-system
    kubectl rollout status deployment cl-dataplane -n clusterlink-system
    

    Server cluster:

    kubectl rollout status deployment cl-controlplane -n clusterlink-system
    kubectl rollout status deployment cl-dataplane -n clusterlink-system
    
Sample output
deployment "cl-controlplane" successfully rolled out
deployment "cl-dataplane" successfully rolled out

Enable cross-cluster access

In this step, we enable connectivity access between the iPerf3 client and server. For each step, you have an example demonstrating how to apply the command from a file or providing the complete custom resource (CR) associated with the command.

Note that the provided YAML configuration files refer to environment variables (defined below) that should be set when running the tutorial. The values are replaced in the YAMLs using envsubst utility.

Installing envsubst on macOS

In case envsubst does not exist, you can install it with:

brew install gettext
brew link --force gettext

Set-up peers

Add the remote peer to each cluster:

Client cluster:

export SERVER_IP=`docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' server-control-plane`
curl -s $IPERF3_FILES/clusterlink/peer-server.yaml | envsubst | kubectl apply -f -
export SERVER_IP=`docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' server-control-plane`
echo "
apiVersion: clusterlink.net/v1alpha1
kind: Peer
metadata:
  name: server
  namespace: clusterlink-system
spec:
  gateways:
    - host: "${SERVER_IP}"
      port: 30443
" | kubectl apply -f -

Server cluster:

export CLIENT_IP=`docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' client-control-plane`
curl -s $IPERF3_FILES/clusterlink/peer-client.yaml | envsubst | kubectl apply -f -
export CLIENT_IP=`docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' client-control-plane`
echo "
apiVersion: clusterlink.net/v1alpha1
kind: Peer
metadata:
  name: client
  namespace: clusterlink-system
spec:
  gateways:
    - host: "${CLIENT_IP}"
      port: 30443
" | kubectl apply -f -

Note

The CLIENT_IP and SERVER_IP refers to the node IP of the peer kind cluster, which assigns the peer YAML file.

Export the iPerf server endpoint

In the server cluster, export the iperf3-server service:

Server cluster:

kubectl apply -f $IPERF3_FILES/clusterlink/export-iperf3.yaml
echo "
apiVersion: clusterlink.net/v1alpha1
kind: Export
metadata:
  name: iperf3-server
  namespace: default
spec:
  port:  5000
" | kubectl apply -f -

Set-up import

In the client cluster, import the iperf3-server service from the server cluster:

Client cluster:

kubectl apply -f $IPERF3_FILES/clusterlink/import-iperf3.yaml
echo "
apiVersion: clusterlink.net/v1alpha1
kind: Import
metadata:
  name: iperf3-server
  namespace: default
spec:
  port:       5000
  sources:
    - exportName:       iperf3-server
      exportNamespace:  default
      peer:             server
" | kubectl apply -f -

Set-up access policies

Create access policies on both clusters to allow connectivity:

Client cluster:

kubectl apply -f $IPERF3_FILES/clusterlink/allow-policy.yaml
echo "
apiVersion: clusterlink.net/v1alpha1
kind: AccessPolicy
metadata:
  name: allow-policy
  namespace: default
spec:
  action: allow
  from:
    - workloadSelector: {}
  to:
    - workloadSelector: {}
" | kubectl apply -f -

Server cluster:

kubectl apply -f $IPERF3_FILES/clusterlink/allow-policy.yaml
echo "
apiVersion: clusterlink.net/v1alpha1
kind: AccessPolicy
metadata:
  name: allow-policy
  namespace: default
spec:
  action: allow
  from:
    - workloadSelector: {}
  to:
    - workloadSelector: {}
" | kubectl apply -f -

For more details regarding policy configuration, see here.

Test service connectivity

Test the iperf3 connectivity between the clusters:

Client cluster:

export IPERF3CLIENT=`kubectl get pods -l app=iperf3-client -o custom-columns=:metadata.name --no-headers`
kubectl exec -i $IPERF3CLIENT -- iperf3 -c iperf3-server --port 5000
Sample output
Connecting to host iperf3-server, port 5000
[  5] local 10.244.0.5 port 51666 connected to 10.96.46.198 port 5000
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec   639 MBytes  5.36 Gbits/sec    0    938 KBytes
[  5]   1.00-2.00   sec   627 MBytes  5.26 Gbits/sec    0    938 KBytes
[  5]   2.00-3.00   sec   628 MBytes  5.26 Gbits/sec    0    938 KBytes
[  5]   3.00-4.00   sec   635 MBytes  5.33 Gbits/sec    0    938 KBytes
[  5]   4.00-5.00   sec   630 MBytes  5.29 Gbits/sec    0    938 KBytes
[  5]   5.00-6.00   sec   636 MBytes  5.33 Gbits/sec    0    938 KBytes
[  5]   6.00-7.00   sec   639 MBytes  5.36 Gbits/sec    0    938 KBytes
[  5]   7.00-8.00   sec   634 MBytes  5.32 Gbits/sec    0    938 KBytes
[  5]   8.00-9.00   sec   641 MBytes  5.39 Gbits/sec    0    938 KBytes
[  5]   9.00-10.00  sec   633 MBytes  5.30 Gbits/sec    0    938 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  6.19 GBytes  5.32 Gbits/sec    0             sender
[  5]   0.00-10.00  sec  6.18 GBytes  5.31 Gbits/sec                  receiver

iperf Done.

Cleanup

  1. Delete kind clusters: Client cluster:

    kind delete cluster --name=client
    

    Server cluster:

    kind delete cluster --name=server
    
  2. Remove tutorial directory:

    cd .. && rm -rf iperf3-tutorial
    
  3. Unset environment variables: Client cluster:

    unset KUBECONFIG IPERF3_FILES IPERF3CLIENT
    

    Server cluster:

    unset KUBECONFIG IPERF3_FILES