exec

JR and K6 distributed in Kubernetes

JR can run with xk6-exec with the distributed K6 in Kubernetes.

Prerequisites

• a Kubernetes cluster
• the K6 operator installed
• the jr image accessible either as built locally or from a registry

Build the image

From the /k6/exec folder launch:

docker build -t k6-jr .

The k6-jr image can launch a script that executes jr in the runner. e.g.:

import exec from 'k6/x/exec';

export default ()=> {
       console.log(exec.command("/usr/bin/jr", ["run",
                                                "net_device",
                                                "-n", "2",
                                                "-f", "100ms",
                                                "-d", "1m"
                                                ]))

}

Create the CR

You can now create the CR from the k6 CRD to run the test. The following example runs jr with a parallelism of 4 and 200 virtual users (e.g. 50 VUs each pod)

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: jr-test
data:
  jr.js: |
    import exec from 'k6/x/exec';

    export const options = {
      vus: 20,
      duration: '5m',
    };
    export default ()=> {
      try{
          var output = exec.command("/usr/bin/jr", ["run",
                                                    "net_device",
                                                    ],{"continue_on_error": true});
      }catch (e) {
        console.log("ERROR: " + e);
        if (e.value && e.value.stderr) {
                console.log("STDERR: " + String.fromCharCode.apply(null, e.value.stderr))
        }
      }


    }    
---
apiVersion: k6.io/v1alpha1
kind: TestRun
metadata:
  name: k6-jr-example
spec:
  parallelism: 4
  script:
    configMap:
      name: jr-test
      file: jr.js
  runner:
    image: registry.localhost:5000/k6-jr:latest

Note: k6 is responsible for running jr with the proper number pf virtual users, duration and parallelism so jr in the script should be run emitting just one sample

To run the example:

kubectl apply -f test-jr-run.yaml

The k6 operator should launch 4 pods with jr runnning for the amount of time declared in the options variable of the javascript test script.

A more complex example with MongoDB producer and Prometheus remote RW

In this example we will run a distributed test with jr using as producer MongoDB and writing the k6 metrics to Prometheus.

The prerequisites are:

• a reachable MongoDB cluster instance
• a reachable Prometheus instance with the remote write receiver enabled

The yaml (self explanatory) of the TestRun CR is the following:

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: jr-configmap
data:
  mongoconfig.json: |
    {
      "mongo_uri": "mongodb+srv://<user>:<password>@...",
      "database": "<mongo database>",
      "collection": "<mongo collection>"
    }
  jr.js: |
    import exec from 'k6/x/exec';

    export const options = {
      vus: 20,
      duration: '5m',
    };
    export default ()=> {
      try{
          var output = exec.command("/usr/bin/jr", ["run",
                                                    "net_device",
                                                    "--output","mongo",
                                                    "--mongoConfig", "/jrconfig/mongoconfig.json"
                                                    ],{"continue_on_error": true});
      }catch (e) {
        console.log("ERROR: " + e);
        if (e.value && e.value.stderr) {
                console.log("STDERR: " + String.fromCharCode.apply(null, e.value.stderr))
        }
      }


    }
---
apiVersion: k6.io/v1alpha1
kind: TestRun
metadata:
  name: k6-jr-example
spec:
  parallelism: 4
  script:
    configMap:
      name: jr-configmap
      file: jr.js
  arguments: -o experimental-prometheus-rw
  runner:
    image: registry.localhost:5000/k6-jr:latest
    env: 
      - name: K6_PROMETHEUS_RW_SERVER_URL
        value: http://<prometheus endpoint>/api/v1/write
      - name: K6_PROMETHEUS_RW_TREND_STATS
        value: "p(95),p(99),min,max"
    volumeMounts:
    - name: config-volume
      mountPath: /jrconfig
    volumes:
    - name: config-volume
      configMap:
        name: jr-configmap