This example tell you how to use the WISE-PaaS rabbitmq service to receive and send message and 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
#download this repository
git clone https://github.com/WISE-PaaS/example-js-docker-iothub.git
#download what package the application need
npm install
#cf login -skip-ssl-validation -a {api.domain_name} -u "account" -p "password"
cf login –skip-ssl-validation -a api.wise-paas.io -u xxxxx@advtech.com.tw -p xxxxxx
#check the cf status
cf target
The file save the config when we push our application to the WISE-PaaS。
(Change manifest.yml application name to yours，because i already use it。)
And we need to bind the rabbitmq(iothub) service in our application so we write it to manifest.yml
(check the Service Instance name in manifest.yml and wise-paas service list，if you doesn't have it，you can create one by click add button)
- name: Define our application serviceName
- memory: The memory we want to give to our app
- disk_quota: The disk we want to give to our app
- command: Start the application
Notice:You can add service instance by yourself
This is a simple backend application and we can get the application config in WISE-PaaS
const express = require("express");
const mqtt = require("mqtt");
const app = express();
app.get("/", (req, res) => {
res.send("mqtt and iothub");
});
var port = process.env.PORT || 3000;
app.listen(port, (res, req) => {
console.log(`listen port on ${port}`);
});
let vcap_services = JSON.parse(process.env.VCAP_SERVICES);
// Start Config
var config = {};
config.mqtt = {};
/** Modify this config ***/
config.timeout = 120 * 1000;
//service name in wise-Paas
config.mqtt.serviceName = "p-rabbitmq";
if (process.env.VCAP_SERVICES != null) {
console.log("Using VCAP_SERVICES");
let vcap_services = JSON.parse(process.env.VCAP_SERVICES);
}
// Parsing credentials from VCAP_SERVICES for binding service
if (vcap_services[config.mqtt.serviceName]) {
console.log("Parsing " + config.mqtt.serviceName);
config.mqtt.broker =
"mqtt://" +
vcap_services[config.mqtt.serviceName][0].credentials.protocols.mqtt.host;
config.mqtt.username = vcap_services[
config.mqtt.serviceName
][0].credentials.protocols.mqtt.username.trim();
config.mqtt.password = vcap_services[
config.mqtt.serviceName
][0].credentials.protocols.mqtt.password.trim();
config.mqtt.port =
vcap_services[config.mqtt.serviceName][0].credentials.protocols.mqtt.port;
}
//MQTT config
config.mqtt.options = {
broker: config.mqtt.broker,
reconnectPeriod: 1000,
port: config.mqtt.port,
username: config.mqtt.username,
password: config.mqtt.password
};
config.mqtt.topic = "/hello"; //top we listen
config.mqtt.retain = true; // MQTT Publish Retainvcap_services can get the environment on WISE-PaaS，
Notice:The config.mqtt.serviceName mush be the same as the WISE-PaaS servicename
This code use to connect to rabbitmq service，you can design the client.on("message",)...
and make it save data or do other thing。
var client = mqtt.connect(config.mqtt.broker, config.mqtt.options);
client.on("connect", function() {
client.subscribe(config.mqtt.topic);
console.log("[MQTT]:", "Connected.");
});
client.on("message", function(topic, message) {
console.log("[" + topic + "]:" + message.toString());
});
client.on("error", function(err) {
console.log(err);
});
client.on("close", function() {
console.log("[MQTT]: close");
});
client.on("offline", function() {
console.log("[MQTT]: offline");
});This file can help us build a docker image
it will use the node docker image first，it will download automatic，and save copy a file to /app ，next to install package by npm install，the port we set in index.js is 3000，and finally start it。
FROM node:8-alpine
ADD . /app
WORKDIR /app
RUN npm install
EXPOSE 3000
CMD npm start
Use docker build to build our image，and it need to in path than we already define the Dockerfile
docker build -t {image name} .
docker build -t example-js-docker-iothub .
Tag image to a docker hub
Docker Hub
#docker login to the docker hub
docker login
#docker tag {image name} {your account/dockerhub-resp name}
docker tag example-js-docker-iothub WISE-PaaS/example-js-docker-iothub
#docker push {your account/dockerhub-resp name}
docker push WISE-PaaS/example-js-docker-iothub
cf push can help us push application to the WISE-PaaS，but first you need to login。
#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}
cf push --docker-image WISE-PaaS/example-js-docker-iothub
Get application environment in WISE-PaaS
cf env example-js-docker-iothub > env.json
const mqtt = require("mqtt");
const mqttUri =
"mqtt://xxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx%3A0516aa2a-0fe5-4683-a9d6-072dcf64df3c:Z2lUsjpx2y0KsohXeytcrRVeQ@40.81.27.10:1883";
// Use mqttUri or connectOpts
const client = mqtt.connect(mqttUri);
client.on("connect", connack => {
setInterval(() => {
publishMockTemp();
}, 3000);
});
// Publish mock random temperature periodically
function publishMockTemp() {
const temp = Math.floor(Math.random() * 7 + 22);
client.publish("/hello", temp.toString(), { qos: 2 }, (err, packet) => {
//if (!err) console.log('Data sent to /hello' + temp);
if (err) {
console.log(err);
} else {
console.log("Data send to /hello " + temp);
}
});
}Edit the publisher.js mqttUri you can find the uri in env.json
- uri :"VCAP_SERVICES => p-rabbitmq => mqtt => uri"
- exnternalhost : "VCAP_SERVICES" => p-rabbitmq => externalHosts
Notice:You need to change the host to externalHosts
to
Open two terminal and check the application
#cf logs {application name}
cf logs example-js-docker-iothub
.
node publisher.js
