jiankaiwang / tcdc_opendataapi_nodejs

The repository is the advanced API (Nodejs-Redis-API) for the visualization charts on Taiwan CDC open data portal.

Taiwan CDC Open Data Visualization API (Nodejs-Redis-API)

The origin opendata api (php-mysql-based, refer to tcdc_opendataapi_php) is not proper under large amount of sessions in quite short term. The cache-based api is necessary. The repository is the advanced API for the visualization charts on Taiwan CDC open data portal (the following image). The visualization api consists of two types, php-mysql-based and nodejs-redis-based ones. The php-mysql-based api is accessed over http/https on port 80/443. The nodejs-redis-based api is accessed over http/https on port 8080/8080. The nodejs-redis-based api is directly accessing the redis cached database which is updated by a task scheduler generating the data (jiankaiwang/tcdc_opendataapi_nodejs_redis).

All the api is designed as the GET operation and the content type is application/json.

Step

• Install Redis and set up password.
• Install Node.js.
• Git clone the repository.

$ cd ~
$ git clone https://github.com/jiankaiwang/tcdc_opendataapi_nodejs.git

• Install necessary package.

$ npm install

• Edit the app.js.

/*
 * desc : open http / https server
 * edit the http or https port
 */
var port = { "http" : 8080, "https" : 8080 }
, allowService = { "http" : false, "https" : true };

if ( allowService["http"] ) {
  http.createServer(app).listen(port["http"], function(){
    console.log('http listening on port ' + port["http"]);
  });
}

if ( allowService["https"] ) {
  var options = {
    key: fs.readFileSync('/etc/letsencrypt/live/example.com/privkey.pem'),
    cert: fs.readFileSync('/etc/letsencrypt/live/example.com/cert.pem'),
    ca: fs.readFileSync('/etc/letsencrypt/live/example.com/chain.pem')
  };

  https.createServer(options, app).listen(port["https"], function(){
    console.log('https listening on port ' + port["https"]);
  });
}

• Edit the opendataplatform.js (under routes\opendataplatform.js).

/*
 * set the available service and its parameters
 * for example: https://od.cdc.gov.tw/(opendataplatform)/?s=(dengue)&v=(a1)
 * () means the information filled in apiService
 */
var apiService = {
	 "dengue" : ["a1", "a2"],
	 "influlinechart" : ["a1"],
	 "enterovirus" : ["a1"],
	 "hivbc" : ["a1"],
	 "diarrheapiechart" : ["a1"]
  };

/*
 * set the redis server connection information
 */
var __redisInfo = {
	"host" : "host",
	"port" : "port",
	"pwd" : "password"
};

• Establish the service.

$ sudo vim /etc/systemd/system/odredisapi.service

[Unit]
Description=OpenData API Service in Redis
After=network.target

[Service]
User=root
Group=root
ExecStart=/usr/bin/node /home/user/tcdc_opendataapi_nodejs/app.js > /var/tmp/odredisapi.log & 2>&1
Restart=always
Environment=PATH=/usr/bin:/usr/local/bin
Environment=NODE_ENV=production
WorkingDirectory=/home/user/tcdc_opendataapi_nodejs

[Install]
WantedBy=multi-user.target

# start the service
$ sudo systemctl start odredisapi.service

# check the service status
$ sudo systemctl status odredisapi.service

# automatically start service
$ sudo systemctl enable odredisapi.service

Access the API

• Surf the link.

<!-- all api is designed as the GET operation -->

<!-- dengue open data api -->
GET http(s)://example.com:8080/opendataplatform/?s=dengue&v=a1
GET http(s)://example.com:8080/opendataplatform/?s=dengue&v=a2

<!-- enterovirus open data api -->
GET http(s)://example.com:8080/opendataplatform/?s=enterovirus&v=a1

<!-- diarrhea open data api -->
GET http(s)://example.com:8080/opendataplatform/?s=diarrheapiechart&v=a1

<!-- influ open data api -->
GET http(s)://example.com:8080/opendataplatform/?s=influlinechart&v=a1

<!-- hiv open data api -->
GET http(s)://example.com:8080/opendataplatform/?s=hivbc&v=a1