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Exercising the deployed example

Once you have one or more Cloudflow applications started, you can use some CLI helpers to monitor the status of your applications.

  • --help to see all options available

$ kubectl-cloudflow --help

This command line tool can be used to deploy and operate Cloudflow applications.

Usage:
  cloudflow [command]

Available Commands:
  configure                 Configures a deployed Cloudflow application.
  deploy                    Deploys a Cloudflow application to the cluster.
  help                      Help about any command
  install-oc-plugin         Installs the Cloudflow OpenShift CLI `oc` plugin.
  list                      Lists deployed Cloudflow application in the current cluster.
  scale                     Scales a streamlet of a deployed Cloudflow application to the specified number of replicas.
  status                    Gets the status of a Cloudflow application.
  undeploy                  Undeploys a Cloudflow application.
  update-docker-credentials Updates docker registry credentials that are used to pull Cloudflow application images.
  version                   Prints the plugin version.

Flags:
  -h, --help   help for cloudflow

Use "cloudflow [command] --help" for more information about a command.
  • list shows all applications deployed in the cluster

$ kubectl-cloudflow list

NAME              NAMESPACE         VERSION           CREATION-TIME
sensor-data       sensor-data       2-89ce8a7         2019-11-12 12:47:19 +0530 IST
  • status shows details of a running application

$ kubectl-cloudflow status sensor-data
Name:             sensor-data
Namespace:        sensor-data
Version:          2-89ce8a7
Created:          2019-11-12 12:47:19 +0530 IST
Status:           Running

STREAMLET         POD                                         STATUS            RESTARTS          READY
valid-logger      sensor-data-valid-logger-76884bb775-86pwh   Running           0                 True
metrics           sensor-data-metrics-6c47bfb489-xd644        Running           0                 True
invalid-logger    sensor-data-invalid-logger-549d687d89-m64l7 Running           0                 True
validation        sensor-data-validation-7dd858b6c5-lcp2n     Running           0                 True
http-ingress      sensor-data-http-ingress-fd9cdb66f-jbsrm    Running           0                 True

Push data to the Application

Our application uses an http based ingress to ingest data. Follow the following steps to push JSON data through the ingress into the application.

  • Get the port details of our ingress streamlet

$ kubectl describe pod sensor-data-http-ingress-fd9cdb66f-jbsrm -n sensor-data
Name:               sensor-data-http-ingress-fd9cdb66f-jbsrm
Namespace:          sensor-data
Priority:           0
PriorityClassName:  <none>
Node:               gke-dg-gke-1-default-pool-162a09d5-ddnq/10.132.0.21
Start Time:         Tue, 12 Nov 2019 12:47:20 +0530
Labels:             app.kubernetes.io/component=streamlet
                    app.kubernetes.io/managed-by=cloudflow
                    app.kubernetes.io/name=sensor-data-http-ingress
                    app.kubernetes.io/part-of=sensor-data
                    app.kubernetes.io/version=2-89ce8a7
                    com.lightbend.cloudflow/app-id=sensor-data
                    com.lightbend.cloudflow/streamlet-name=http-ingress
                    pod-template-hash=fd9cdb66f
Annotations:        prometheus.io/scrape: true
Status:             Running
IP:                 10.44.1.6
Controlled By:      ReplicaSet/sensor-data-http-ingress-fd9cdb66f
Containers:
  sensor-data-http-ingress:
    Container ID:  docker://9149cd757094e7ea1b943076048b7efc7aa343da8c2d598bba31295ef3cbfd6b
    Image:         eu.gcr.io/bubbly-observer-178213/sensor-data@sha256:ee496e8cf3a3d9ab71c3ef4a4929ed8eeb6129845f981c33005942314ad30f18
    Image ID:      docker-pullable://eu.gcr.io/bubbly-observer-178213/sensor-data@sha256:ee496e8cf3a3d9ab71c3ef4a4929ed8eeb6129845f981c33005942314ad30f18
    Ports:         3000/TCP, 2048/TCP, 2049/TCP, 2050/TCP
...

The streamlet exposes its HTTP endpoint for uploading data on port 3000 - let’s set up a port forwarding on it.

  • Setup port forwarding for the Pod port

$ kubectl port-forward sensor-data-http-ingress-fd9cdb66f-jbsrm -n sensor-data 3000:3000
Forwarding from 127.0.0.1:3000 -> 3000
Forwarding from [::1]:3000 -> 3000
Handling connection for 3000
The port-forward solution used here is a temporary route to the application from localhost. If you want to create a permanent route that can be accessed by anyone, please see the following chapter on Kubernetes ingresses: Providing External Access to Cloudflow Services
  • Push data to the application. In order to do that follow the steps:

  • create a json file named data.json with the content {"deviceId":"c75cb448-df0e-4692-8e06-0321b7703992","timestamp":1495545346279,"measurements":{"power":1.7,"rotorSpeed":23.4,"windSpeed":100.1}}

  • run the following bash script:

 for str in $(cat test-data/10-storm.json)
do
  echo "Using $str"
  curl -i -X POST http://localhost:3000 -H "Content-Type: application/json" --data "$str"
done
  • Note that we are using the port number 3000 of localhost to which we mapped the Pod port. This JSON record will pass through the stages of transformation within the pipeline that we defined in the blueprint.

Verify the Application works

Check the log of the streamlet valid-logger to verify that you get the proper transformed metric.

$ kubectl logs sensor-data-valid-logger-76884bb775-86pwh -n sensor-data

Towards the end of the log you will see something like the following getting printed out:

[INFO] [11/12/2019 07:57:04.369] [akka_streamlet-akka.actor.default-dispatcher-4] [akka.actor.ActorSystemImpl(akka_streamlet)] {"deviceId": "c75cb448-df0e-4692-8e06-0321b7703992", "timestamp": 1495545346279, "name": "rotorSpeed", "value": 23.4}
[INFO] [11/12/2019 07:57:04.375] [akka_streamlet-akka.actor.default-dispatcher-4] [akka.actor.ActorSystemImpl(akka_streamlet)] {"deviceId": "c75cb448-df0e-4692-8e06-0321b7703992", "timestamp": 1495545346279, "name": "power", "value": 1.7}
[INFO] [11/12/2019 07:57:04.375] [akka_streamlet-akka.actor.default-dispatcher-4] [akka.actor.ActorSystemImpl(akka_streamlet)] {"deviceId": "c75cb448-df0e-4692-8e06-0321b7703992", "timestamp": 1495545346279, "name": "windSpeed", "value": 100.1}

Undeploy the Application

$ kubectl-cloudflow undeploy sensor-data