Multi-Cluster Slice: iPerf Deployment

Introduction

iPerf is a tool commonly used to measure network performance, perform network tuning, and more. The iPerf application consists of two main services, iperf-sleep (client) and iperf-server.

This tutorial provides the steps to:

• Install the iperf-sleep and iperf-server services on two clusters within a KubeSlice configuration.
• Verify inter-cluster communication over KubeSlice.

Prerequisites

Before you begin, ensure the following prerequisites are met:

• You have a KubeSlice configuration with two or more clusters registered. For more information, see Installing KubeSlice and Registering the Worker Cluster.
• Before creating the slice, create a iperf namespace in all participating worker clusters. Use the following command to create the iperf namespace:

  kubectl create ns iperf
• You have the slice created across the worker clusters. For more information, see Create a Slice.

Create the Slice Configuration YAML File

Use the following template to create the Slice without Istio:

apiVersion: controller.kubeslice.io/v1alpha1
kind: SliceConfig
metadata:
 name: <slice-name>
spec:
 sliceSubnet: <slice-subnet>  #For example: 10.32.0.0/16
 sliceType: Application
 sliceGatewayProvider:
   sliceGatewayType: OpenVPN
   sliceCaType: Local
 sliceIpamType: Local
 clusters:
   - <worker-cluster-name>
 qosProfileDetails:
   queueType: HTB
   priority: 1
   tcType: BANDWIDTH_CONTROL
   bandwidthCeilingKbps: 5120
   bandwidthGuaranteedKbps: 2560
   dscpClass: AF11
 namespaceIsolationProfile:
   applicationNamespaces:
    - namespace: iperf
      clusters:
      - <worker-cluster-name>
   isolationEnabled: false                   #make this true in case you want to enable isolation
   allowedNamespaces:
    - namespace: kube-system
      clusters:
      - <worker-cluster-name>

Apply the Slice Configuration

The following information is required.

Variable	Description
<cluster name>	The given name of the cluster.
<slice configuration>	The name of the slice configuration file
<project namespace>	The project namespace on which you apply the slice configuration file.

Perform these steps:

1. Switch the context to the KubeSlice Controller using the following command:

   kubectx <cluster name>

2. Apply the YAML file on the project namespace using the following command:

   kubectl apply -f <slice configuration>.yaml -n <project namespace>

Deploy iPerf

In this tutorial, iperf-sleep and iperf-server will be deployed in the two different clusters. The cluster used for iperf-sleep is referred to as sleep cluster, and the cluster used for iperf-server is referred to as server cluster.

Create the iPerf Sleep YAML File

Use the following template to create a iperf-sleep.yaml deployment file.

apiVersion: apps/v1
kind: Deployment
metadata:
 name: iperf-sleep
 namespace: iperf
 labels:
   app: iperf-sleep
spec:
 replicas: 1
 selector:
   matchLabels:
     app: iperf-sleep
 template:
   metadata:
     labels:
       app: iperf-sleep
   spec:
     containers:
     - name: iperf
       image: mlabbe/iperf
       imagePullPolicy: Always
       command: ["/bin/sleep", "3650d"]
     - name: sidecar
       image: nicolaka/netshoot
       imagePullPolicy: IfNotPresent
       command: ["/bin/sleep", "3650d"]
       securityContext:
         capabilities:
           add: ["NET_ADMIN"]
         allowPrivilegeEscalation: true
         privileged: true

Apply the iPerf Sleep YAML File

Perform these steps:

1. Switch the context to the registered cluster you want to install iperf-sleep.

   kubectx <cluster name>
2. Create the iperf namespace using the following command:

   kubectl create ns iperf
3. Apply the iperf-sleep.yaml deployment file using the following command:

   kubectl apply -f iperf-sleep.yaml -n iperf

Create the iPerf Server YAML File

Using the following template create a iperf-server.yaml deployment file. All fields in the template will remain the same except for one slice name instances which must be replaced with the name of your slice.

apiVersion: apps/v1
kind: Deployment
metadata:
 name: iperf-server
 namespace: iperf
 labels:
   app: iperf-server
spec:
 replicas: 1
 selector:
   matchLabels:
     app: iperf-server
 template:
   metadata:
     labels:
       app: iperf-server
   spec:
     containers:
     - name: iperf
       image: mlabbe/iperf
       imagePullPolicy: Always
       args:
         - '-s'
         - '-p'
         - '5201'
       ports:
       - containerPort: 5201
         name: server
     - name: sidecar
       image: nicolaka/netshoot
       imagePullPolicy: IfNotPresent
       command: ["/bin/sleep", "3650d"]
       securityContext:
         capabilities:
           add: ["NET_ADMIN"]
         allowPrivilegeEscalation: true
         privileged: true
---
apiVersion: networking.kubeslice.io/v1beta1
kind: ServiceExport
metadata:
 name: iperf-server
 namespace: iperf
spec:
 slice: <slice-name>
 selector:
   matchLabels:
     app: iperf-server
 ingressEnabled: false
 ports:
 - name: tcp
   containerPort: 5201
   protocol: TCP

Apply the iPerf Server YAML File

Perform these steps:

1. Switch the context to the registered cluster you want to install the iperf server.

   kubectx <cluster name>
2. Create the iperf namespace using the following command:

   kubectl create ns iperf
3. Apply the iperf-server.yaml deployment file using the following command:

   kubectl apply -f iperf-server.yaml -n iperf

Validate your iPerf Installation

To verify our iPerf installation, first switch the context to the cluster with the iperf-sleep.yaml applied.

Validate the iPerf Sleep Installation

Perform these steps:

1. Switch the context to the cluster where you installed the iperf Sleep.

   kubectx <cluster name>

2. Validate the iperf-sleep pods belonging to the iperf namespace using the following command:

   kubectl get pods -n iperf

   Example Output

   NAME                           READY   STATUS    RESTARTS   AGE
   iperf-sleep-5477bf94cb-vmmtd   3/3     Running   0          10s

3. Validate the ServiceImport using the following command:

   kubectl get serviceimport -n iperf

   Example Output

   NAME           SLICE   PORT(S)   ENDPOINTS   STATUS  ALIAS
   iperf-server   lion              1           READY

Validate the iPerf Server Installation

Perform these steps:

1. Switch the context to the cluster where you have installed the iperf Server.

   kubectx <cluster name>
2. Validate the iperf-server pods belonging to the iperf namespace using the following command:

   kubectl get pods -n iperf
   Example Output

   NAME                            READY   STATUS    RESTARTS   AGE
   iperf-server-5958958795-fld2p   3/3     Running   0          20s
3. Validate the ServiceImport using the following command:

   kubectl get serviceimport -n iperf
   Example Output

   NAME           SLICE   PORT(S)   ENDPOINTS   STATUS  ALIAS
   iperf-server   lion              1           READY
4. Validate the ServiceExport using the following command:

   kubectl get serviceexport -n iperf
   Example Output

   NAME           SLICE   INGRESS   SERVICEPORT(S)   PORT(S)    ENDPOINTS   STATUS    ALIAS
   iperf-server   lion                               5201/TCP   1           READY

Validate ServiceExport and ServiceImport

Perform these steps in the cluster where KubeSlice Controller is installed:

1. Switch the context of the cluster.

   kubectx <cluster name>

2. Validate serviceexportconfig using the following command:

   kubectl get serviceexportconfigs -A

   Example Output

   NAMESPACE          NAME           AGE
   kubeslice-devops   iperf-server   5m12s

3. Validate the workerserviceimports using the following command:

   kubectl get workerserviceimports -A

   Example Output

   NAMESPACE          NAME                                      AGE
   kubeslice-devops   iperf-server-iperf-lion-worker-cluster-1   5m59s
   kubeslice-devops   iperf-server-iperf-lion-worker-cluster-2   5m59s

Get the DNS Name

Use the following command to describe the iperf-server service and retrieve the short and full DNS names for the service. We will use the short DNS name later to verify the inter-cluster communication.

kubectl describe serviceimport iperf-server -n iperf | grep "Dns Name:"

Expected Output

Dns Name:  iperf-server.iperf.svc.slice.local #The DNS Name listed here will be used as the DNS Name below.
Dns Name: <iperf server service>.<cluster identifier>.iperf-server.iperf.svc.slice.local #Full DNS Name

Verify the Inter-Cluster Communication

Perform these steps:

1. Switch the context of the cluster.

   kubectx <cluster name>

2. List the pods in the iperf namespace to get the full name of the iperf-sleep pod.

   kubectl get pods -n iperf

3. Using the pod name you just retrieved, execute the command into the iperf-sleep pod with the following command:

   kubectl exec -it <iperf-sleep pod name> -c iperf -n iperf -- sh

4. After attaching the pod, use the short DNS Name retrieved above to connect to the server from the sleep pod.

   iperf -c <short iperf-server DNS Name> -p 5201 -i 1 -b 10Mb;

Expected Output

If the iperf-sleep pod is able to reach the iperf-server pod across clusters, you should see similar output to that below.

> kubectl exec -it iperf-sleep-5477bf94cb-vmmtd -c iperf -n iperf -- sh
/ $ iperf -c iperf-server.iperf.svc.slice.local -p 5201 -i 1 -b 10Mb;
------------------------------------------------------------
Client connecting to iperf-server.iperf.svc.slice.local, TCP port 5201
TCP window size: 45.0 KByte (default)
------------------------------------------------------------
[  1] local 10.1.1.89 port 38400 connected with 10.1.2.25 port 5201
[ ID] Interval       Transfer     Bandwidth
[  1] 0.00-1.00 sec  1.25 MBytes  10.5 Mbits/sec
[  1] 1.00-2.00 sec  1.25 MBytes  10.5 Mbits/sec
[  1] 2.00-3.00 sec  1.25 MBytes  10.5 Mbits/sec
[  1] 3.00-4.00 sec  1.25 MBytes  10.5 Mbits/sec
[  1] 4.00-5.00 sec  1.25 MBytes  10.5 Mbits/sec
[  1] 5.00-6.00 sec  1.25 MBytes  10.5 Mbits/sec
[  1] 6.00-7.00 sec  1.25 MBytes  10.5 Mbits/sec
[  1] 7.00-8.00 sec  1.25 MBytes  10.5 Mbits/sec
[  1] 8.00-9.00 sec  1.25 MBytes  10.5 Mbits/sec
[  1] 9.00-10.00 sec  1.25 MBytes  10.5 Mbits/sec
[  1] 0.00-10.00 sec  12.8 MBytes  10.7 Mbits/sec
/ $

Uninstall iPerf

To uninstall iPerf application from your KubeSlice configuration, follow the instructions in offboarding namespaces.