nodeでmongoバックエンドのAPIサーバーを作る

Dockerfile

FROM node:9.11.1-alpine

WORKDIR /app

COPY package.json /app
COPY package-lock.json /app
RUN npm install --production
EXPOSE 3000

COPY src /app/src

CMD npm start

index.js

const express = require('express');

const NATS = require('nats');
var nats = NATS.connect({
    servers: ['nats://nats:4222']
});

const app = express();
const assert = require('assert');

// MongoDB
let db;
const MongoClient = require('mongodb').MongoClient;

const MONGO_URL = 'mongodb://mongo-0.mongo:27017,mongo-1.mongo:27017,mongo-2.mongo:27017/test?replicaSet=rs0';

// // Simple Publisher
// nats.publish('foo', 'Hello World!');


const LISTS_COLLECTION_NAME = 'lists';

const mongoOptions = {
    replicaSet: 'rs0',
    ssl: false,
    sslValidate: false,
    poolSize: 5,
    reconnectTries: 1,
};

MongoClient.connect(MONGO_URL, mongoOptions, function(err, mongodb) {
    assert.equal(null, err);
    console.log("Connected correctly to server");
    db = mongodb;
});

function collection(name) {
    return db.collection(name);
}


app.get('/', (req, res) => {
    // res.json({
    //     hello: 'world',
    // });
    collection(LISTS_COLLECTION_NAME).find().toArray(function(err, docs){
        res.send(docs);
    })
});

app.post('/', function (req, res, next) {
    collection(LISTS_COLLECTION_NAME).insertOne(req.body).then(function(r) {
        res.send(r);
      });
});


/* 2. listen()メソッドを実行して3000番ポートで待ち受け。*/
const server = app.listen(3000, function () {
    console.log("Node.js is listening to PORT:" + server.address().port);
});

package.json

{
  "name": "web-api",
  "version": "0.0.0",
  "description": "web-api",
  "main": "src/index.js",
  "scripts": {
    "start": "node src/index.js",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "private": true,
  "license": "ISC",
  "dependencies": {
    "express": "^4.16.3",
    "mongodb": "^2.2.35",
    "nats": "^0.8.10"
  }
}