This example tell you how to use the WISE-PaaS rabbitmq service to receive and send message use PostgreSQL save it，we use docker package our application。
Use to push application to WISE-PaaS，if you want to know more you can see this video
Use to packaged our application
You can download pgAdmin so you can see the result in WISE-PaaS Postgresql servince instance
#download this repository
git clone https://github.com/WISE-PaaS/example-js-docker-iothub-postgresql.git
#download what package the application need
npm install
Simple backend application and what package what we need。
const mqtt = require("mqtt");
const express = require("express");
const moment = require("moment");
const { Pool } = require("pg");
const app = express();
const port = process.env.PORT || 3000;
app.listen(port, () => {
console.log(` -- Server started on port ${port}!`);
});The vcapServices can get the application environment on WISE-PaaS，so we can get our service config to connect it。
// ----- Remote DB --- Get env variables
const vcap_services = JSON.parse(process.env.VCAP_SERVICES);
postgresql_service_name = "postgresql-innoworks";
const host = vcap_services[postgresql_service_name][0].credentials.host;
const user = vcap_services[postgresql_service_name][0].credentials.username;
const password = vcap_services[postgresql_service_name][0].credentials.password;
const dbPort = vcap_services[postgresql_service_name][0].credentials.port;
const database = vcap_services[postgresql_service_name][0].credentials.database;
const pool = new Pool({
host: host,
user: user,
password: password,
port: dbPort,
database: database,
max: 3,
idleTimeoutMillis: 5000,
connectionTimeoutMillis: 2000
});
This code define the group、schema、table and we create schema and table and bind to group。
group_name = "groupFamily";
schema_name = "home";
table_name = "temperature";
// SQL commands for creating table for storing data
const queryString = `
CREATE SCHEMA IF NOT EXISTS "${schema_name}";
ALTER SCHEMA "${schema_name}" OWNER TO "${group_name}";
CREATE TABLE IF NOT EXISTS "${schema_name}"."${table_name}"(
id serial,
timestamp timestamp (2) default current_timestamp,
temperature integer,
PRIMARY KEY (id)
);
ALTER TABLE "${schema_name}"."${table_name}" OWNER to "${group_name}";
GRANT ALL ON ALL TABLES IN SCHEMA "${schema_name}" TO "${group_name}";
GRANT ALL ON ALL SEQUENCES IN SCHEMA "${schema_name}" TO "${group_name}";
`;
// Execute the SQL commands for startup
pool
.query(queryString)
.then(result => {
console.log("@" + formatTime() + " -- Schema and table initialized.");
})
.catch(err => console.error("Error adding table...", err.stack));
app.get("/", (req, res) => {
res.send("hello world");
});
app.get("/temps", (req, res) => {
const queryString = `
SELECT *
FROM (SELECT * FROM ${schema_name}.${table_name} ORDER BY timestamp DESC LIMIT ${numOfTempsReturned})
AS lastRows
ORDER BY timestamp ASC;
`;
pool
.query(queryString) // No need to connect
.then(result => {
res.setHeader("Access-Control-Allow-Origin", "*");
// Format timestamp
result.rows.map(row => {
row.timestamp = moment(row.timestamp).format("MM-DD HH:mm:ss");
});
res.send({ temperatures: result.rows });
// res.render('index', { recipes: result['rows'] });
})
.catch(err => console.error("Error executing query...", err.stack));
});Connect to the rabbitmq service and insert data use client.on('message',...)
const vcapServices = JSON.parse(process.env.VCAP_SERVICES);
rabbitmq_service_name = "p-rabbitmq";
const mqttUri =
vcapServices[rabbitmq_service_name][0].credentials.protocols.mqtt.uri;
const client = mqtt.connect(mqttUri);
// Subscribe
client.on("connect", connack => {
client.subscribe("home/temperature", (err, granted) => {
if (err) console.log(err);
console.log(
"@" + formatTime() + " -- Subscribed to the topic: home/temperature"
);
});
});
// Receiving data
client.on("message", (topic, message, packet) => {
let time = formatTime();
console.log(`@${time} -- Got data from: ${topic}`);
// mock temperature data
const temp = message.toString();
const queryString =
"INSERT INTO home.temperature(temperature) VALUES($1) RETURNING *";
const values = [temp];
pool
.query(queryString, values)
.then(result => {
console.log("Data added: ", result["rows"][0]);
})
.catch(err => console.error("Error adding data...", err.stack));
});
// Return current formatted time
function formatTime() {
const currentDate = new Date();
return (
currentDate.getHours() +
":" +
currentDate.getMinutes() +
":" +
currentDate.getSeconds()
);
}(Notice:The rabbitmq_service_namealso need to same as WSIE-PaaS)
This file save the config when we push application to the WISE-PaaS，name is your application name，memory and memory、disk_quota is how much memory and disk we give，command is to start our application。
(Notice:You need to change the name because i already use it)
---
applications:
#application name
- name: example-js-docker-iotpost
#buildpack: nodejs_buildpack
memory: 256M
disk_quota: 256M
command: node index.js
Dockerfile can help us download the package what we need。
Dockerfile
FROM node:8-alpine
COPY . /app
ADD . /app
WORKDIR /app
RUN npm install
EXPOSE 3000
CMD npm start
docker build -t {image name} .
docker build -t example-js-docker-iotpost .
Tag image to a docker hub
Docker Hub
#docker tag {image name} {your account/dockerhub-resp name}
docker tag example-js-docker-iotpost WISE-PaaS/example-js-docker-iotpost
#login to the docker hub
docker login
#docker push {your account/dockerhub-resp name}
docker push WISE-PaaS/example-js-docker-iotpost
#cf login -a api.{domain name} -u {WISE-PaaS/EnSaaS account} -p {WISE-PaaS/EnSaaS password}
cf login -a api.wise-paas.io -u xxxxx@advantech.com -p xxxxxxxx
#cf push --docker-image {your account/dockerhub-resp} --no-start
cf push --docker-image tsian077/example-js-docker-iotpost --no-start
The postgresql_service_name and iothub_service_name must be same in WISE-PaaS Service Instance name
Bind the service instance to our application，and the group we define in code must be same。
cf bs {application name} {postgresql_service_name} -c '{\"group\":\"groupFamily\"}'
cf bs example-js-docker-iotpost postgresql -c '{\"group\":\"groupFamily\"}'
cf bs {application name} {iothub_service_name}
cf bs example-js-docker-iotpost rabbitmq
cf start {application name}
cf start example-js-docker-iotpost
Get application environment in WISE-PaaS
#cf env {application_nmae} > env.json
cf env example-js-docker-iot-mongo > env.json
const mqtt = require("mqtt");
const mqttUri =
"mqtt://xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx%3Af4e2645e-469d-4d37-b3fd-cdb830e999a5:VhHlRCA9nEMOauXaKGhyv78ol@40.81.26.31:1883";
const client = mqtt.connect(mqttUri);
client.on("connect", connack => {
setInterval(() => {
publistMockTemp();
}, 3000);
});
function publistMockTemp() {
const temp = Math.floor(Math.random() * 7 + 22);
client.publish(
"home/temperature",
temp.toString(),
{ qos: 2 },
(err, packet) => {
if (!err) console.log("Data sent to home/temperature -- " + temp);
}
);
}- uri :"VCAP_SERVICES => p-rabbitmq => mqtt => uri"
- exnternalhost : "VCAP_SERVICES => p-rabbitmq => externalHosts"
when you get it you need to change the host to externalHosts
to
open two terminal
#cf logs {application name}
cf logs example-js-docker-iothub
.
node publisher.js
(The apllication name maybe different)
You can watch the row data use Postgresql-pgAdmin，and the config can find in WISE-PaaS Application Environment(WISE-PaaS/EnSaaS => application List => click application => environment)
pgAdmin create server(Servers => right click => Create => Server)
- address => VCAP_SERVICES => mongodb-innoworks => 0 => external_host
- Database => VCAP_SERVICES => mongodb-innoworks => 0 => credentials => database
- Username => VCAP_SERVICES => mongodb-innoworks => 0 => credentials => username
- Password => VCAP_SERVICES => mongodb-innoworks => 0 => credentials => password
(Databases => Schemas => Tables => right click => View/Edit data)
