Deploying the iPerf Application on an Intra-cluster Slice

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 a single worker cluster within a KubeSlice configuration.
• Verify intra-cluster communication over KubeSlice.

Prerequisites

Before you begin, ensure the following prerequisites are met:

• You have the KubeSlice Controller components and worker cluster components on the same cluster. For more information, see Installing KubeSlice.
• Before creating a slice, create the iperf namespace in all the participating worker clusters. Use the following command to create the iperf namespace:

  kubectl create ns iperf

Creating a Slice

To install the iPerf application on a single cluster, you must create a slice without Istio enabled.

Creating the Slice Configuration YAML File

Use the following template to create a slice without Istio enabled:

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>
   applicationNamespaces:
   isolationEnabled: false                   #make this true in case you want to enable isolation
   allowedNamespaces:
    - namespace: kube-system
      clusters:
      - <worker-cluster-name>

Applying the Slice Configuration

The following information is required.

Variable	Description
<cluster name>	The name of the cluster.
<slice configuration>	The name of the slice configuration file.
<project name>	The project name 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>

Deploying iPerf

In this tutorial, iperf-sleep and iperf-server will be deployed in the same worker clusters. The cluster is used for iperf-sleep is referred to as sleep cluster as well as for iperf-server. Therefore it is also referred to as server cluster.

Creating 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

Applying 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. Apply the iperf-sleep.yaml deployment file using the following command:

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

Creating 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 instance 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
 ports:
 - name: tcp
   containerPort: 5201
   protocol: TCP

Applying the iPerf Server YAML File

Install the iperf server on the same worker cluster that has iperf sleep installed, you must remain on the same context of the worker cluster.

Apply the iperf-server.yaml deployment.

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

Validating your iPerf Installation

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

Validating the iPerf Sleep Installation

Perform these steps:

1. Switch the context to the worker cluster.

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

   kubectl get pods -n iperf
3. Validate the ServiceImport using the following command:

   kubectl get serviceimport -n iperf
   Example Output

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

Validating the iPerf Server Installation

Perform these steps:

1. Switch the context to the worker cluster.

   kubectx <cluster name>

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

   kubectl get pods -n iperf

3. Validate the ServiceImport using the following command:

   kubectl get serviceimport -n iperf

   Example Output

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

4. Validate the ServiceExport using the following command:

   kubectl get serviceexport -n iperf

   Example Output

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

Validating ServiceExportconfig and ServiceImportconfig

Perform these steps on the worker 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

Getting the DNS Name

Use the following command to describe the iperf-server service and retrieve the short and full DNS names for the service. 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

Verifying the Intra-Cluster Communication

Perform these steps:

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

   kubectl get pods -n iperf
2. 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
3. Once attached to 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;

Example Output

If the iperf-sleep pod is able to reach the iperf-server pod, 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
/ $

Uninstalling iPerf

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