License

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Purpose

The purpose of this demo is to show how simple it is to create a serverless and scalable architecture using GCP. The script will guide you through the creation of all the GCP components needed to:

• ingest data from a device
• process data
• analyse data

Requirements:

• a GCP account
• a GCP project
• gcloud. Alternatevely, you can use the Cloud Shell
• JDK and maven

How to run the demo:

Set parameters

Export yout project id in GCLOUD_PROJECT, then:

. set_params.sh

Login into gcloud

gcloud auth login

Set the projectID in gcloud

gcloud config set project $projectID

Create the temp location in CloudStorage

gsutil mb gs://$bucket/ && touch a-file && echo "temp" > a-file && gsutil cp a-file gs://$tempLocation && rm a-file

Perform local operations in a sandbox

mkdir -p $home
cd $home

Create pubsub topic

gcloud beta pubsub topics create $topic

Configure IAM account for Cloud IoT

In the IAM section of the Cloud Console: add the special account [email protected] with the role Publisher to the PubSub topic (it is needed to allow Cloud IoT to push into PubSub messages received on the MQTT broker). Alternatevely use the gcloud command.

gcloud projects add-iam-policy-binding $projectID \
--member serviceAccount:[email protected] --role roles/pubsub.publisher | grep iot -a1

Create CloudIoT instance

gcloud beta iot registries create $registryName \
    --project=$projectID \
    --region=$iotzone \
    --event-pubsub-topic=$topicFullName

Clone client code

git clone https://github.com/aulisse/java-docs-samples/

Generate keys to be used for securing device/cloud connectivity

./java-docs-samples/iot/api-client/generate_keys.sh

Register a device

gcloud beta iot devices create $deviceName \
  --project=$projectID \
  --region=$iotzone \
  --registry=$registryName \
  --public-key path=rsa_cert.pem,type=rs256

Create BigQuery DataSet & Table

bq mk $dataset
bq mk -t $table message:string,city:string,temperature:float,hour:integer

Run pipeline

Enable DataFlow apis, then run the pipeline using PubSub-2-BigQuery Template

gcloud service-management enable dataflow.googleapis.com

curl -X POST -H "Content-Type: application/json" -H "Authorization: Bearer $(gcloud auth print-access-token)" https://dataflow.googleapis.com/v1b3/projects/$projectID/templates:launch?gcsPath=gs://dataflow-templates/pubsub-to-bigquery/template_file -d  '{"jobName":"'$jobName'","parameters":{"topic":"'$topicFullName'","table":"'$table'"},"environment":{"tempLocation":"gs://'$tempLocation'","maxWorkers":"'$maxWorkers'","zone":"'$dataflowzone'"}}'

Move to Java client folder

cd $home/java-docs-samples/iot/api-client/mqtt_example

Modify code:

Using an IDE or a text editor modify the following row as described. Files are located in subfolder 'src/main/java/com/google/cloud/iot/examples/'

• MqttExample.java, line 159

String payload = String.format("{\"message\":\"%s/%s-message-%d\",\"city\":\"Milan\",\"temperature\":\""+(20+new java.util.Random().nextDouble()*5)+"\",\"hour\":\""+(new java.util.Random().nextInt(24))+"\"}", options.registryId, options.deviceId, i);

• MqttExample.java, line 172

sleep 300 ms 

Feel free to change values for payload and sleep but do not modify the json structure of the payload.

Clean and compile

mvn clean compile

Run MQTT client

mvn exec:java -Dexec.mainClass="com.google.cloud.iot.examples.MqttExample" -Dexec.args="-project_id='$projectID' -registry_id='$registryName' -device_id='$deviceName' -private_key_file=../../../../rsa_private_pkcs8 -algorithm=RS256 -mqtt_bridge_port=443 -num_messages=1000"

Run queries during the ingestion

bq query "select count(*) as count FROM [$table]"
bq query "SELECT hour, avg(temperature) as avg_temp FROM [$table] group by hour order by hour asc"

If the Java client did not finish yet, run the queries in another shell window (run set_params.sh before running the queries). Alternatevely, you can run the queries in BigQuery console and then click "Save to Google Sheets" (where you might want to leverage the Explore feature - bottom right corner of the sheet - to generate automatically a chart)

How to shut down the demo:

Run set_params.sh and clean.sh to free up resources