Running a receiver application on a PC

To run a receiver app on a PC, follow the sequence described here:

1. Install and launch a PostgreSQL container:

docker run --rm --name postgres-container -e POSTGRES_PASSWORD=password -it -p 5433:5432 postgres

docker exec -it postgres-container createdb -U postgres iot-book

2. Create the receiver folder.

3. Create the ./receiver/package.json file with the following content:

{
"name": "receiver",
"version": "1.0.0",
"description": "",
"main": "index.js",
"scripts": {
  "start": "node index.js",
  "test": "echo \"Error: no test specified\" && exit 1"
},
"author": "",
"license": "ISC",
"dependencies": {
  "pg": "^6.2.3"
}
}

4. Create the ./receiver/index.js file with the following content, replacing the database credentials with the correct values:

var restify = require('restify');
var server = restify.createServer({name: 'MyApp'});
server.use(restify.bodyParser());

var Pool = require('pg').Pool;
var pool = new Pool({
  database: 'iot-book',
  host: 'host',
  password: 'password',
  port: 5433,
  user: 'postgres',
});

//ensure table exists in db
pool.query('CREATE TABLE IF NOT EXISTS "sensor-logs" (id serial NOT NULL PRIMARY KEY, data json NOT NULL)', function (err, result) {
  if (err) console.log(err);
});

server.post('/', function create(req, res, next) {
  console.log(req.params);

  //save in db
  pool.query('INSERT INTO "sensor-logs" (data) VALUES ($1)', [req.params], function (err, result) {
    if (err) console.log(err);
    res.send(201, result);
  });

  return next();
});

server.get('/stats', function search(req, res, next) {
  pool.query('SELECT AVG("Variable1"), MAX("Variable1"), MIN("Variable1"), COUNT(*), SUM("Variable1") FROM (SELECT (data->>\'Variable1\')::int "Variable1" FROM "sensor-logs" ORDER BY id DESC LIMIT 10) data', function (err, result) {
    if (err) console.log(err);
    res.send(result.rows);
  });
  return next();
});

server.listen(process.env.PORT || 8080);

5. Create the ./receiver/Dockerfile file with the following content:

FROM node:boron-onbuild
EXPOSE 8080

6. Build an image and run a Docker container:

# Build an image from a Dockerfile
docker build -t opcua-receiver .

# Run container in foreground
docker run -p 8080:8080 -it --rm --name opcua-receiver-container opcua-receiver

# Run container in background
# docker run -p 8080:8080 -d --rm --name opcua-receiver-container opcua-receiver

# Fetch the logs of a container
# docker logs -f opcua-sensor-container

# Stop running container
# docker stop opcua-receiver-container