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

Objective

This tutorial is designed to aid you in improving your understanding of deploying applications.

Prerequisites

Before you begin, ensure the following prerequisites are met:

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

  kubectl create ns iperf

Create a Slice

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

Create the Slice Configuration YAML File

Use the following template to create an intra-cluster slice:

apiVersion: controller.kubeslice.io/v1alpha1
kind: SliceConfig
metadata:
 name: <slice-name>
spec:
 sliceSubnet: <slice-subnet>  #For example: 10.32.0.0/16
 maxClusters: <2 - 32>      # The default value is 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 YAML File

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.

To apply the YAML file:

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 same worker cluster. The cluster is used for iperf-sleep is referred to as sleep cluster and the same clusters is used for iperf-server. Therefore it is also referred to as server cluster.

Creating iPerf Sleep YAML File

Create the iperf-sleep.yaml file using the below template.

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

To apply the YAML file:

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

   kubectx <cluster name>
2. Apply the iperf-sleep.yaml deployment using the following command.

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

Create the iPerf Server YAML File

Create the iperf-server.yaml file using the below template. All the fields in the template remain the same except for <slice name> instance. Replace the <slice name> 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

To install the iperf server on the same worker cluster that has iperf sleep installed, remain on the same context of the worker cluster.

Apply the iperf-server.yaml file using the following command:

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

Validate your iPerf Installation

Validate the installation of iperf-sleep and iperf-server by checking the status of the application pods.

Validate the iPerf Sleep Installation

To validate the iperf-sleep installation:

1. Switch the context to the worker cluster with the iperf-sleep.yaml applied.

   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

Validate the iPerf Server Installation

To validate the iperf-server installation:

1. Switch the context to the worker cluster.

   kubectx <cluster name>
2. Validate the iperf-server pods belonging to the iperf namespace use 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   SERVICEPORT(S)   PORT(S)    ENDPOINTS   STATUS
   iperf-server   lion                               5201/TCP   1           READY

Validate ServiceExportconfig and ServiceImportconfig

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

1. Switch the context of the cluster.

   kubectx <cluster name>
2. Validate the serviceexportconfig use 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 Intra-Cluster Communication

To verify the intra-cluster communication:

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. 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
   /$

This completes the verification of intra-cluster communication.

Uninstall iPerf

To uninstall iPerf from your KubeSlice configuration, the instructions in uninstall KubeSlice