main.js

const { Pool } = require("pg");
const path = require("path");
const fs = require("fs");
require("dotenv").config();

var config = {
  user: process.env.APPLICATION_DB_USER,
  host: process.env.POSTGRES_HOST,
  password: process.env.APPLICATION_DB_INITIAL_PASSWORD,
  database: process.env.POSTGRES_DB,
  port: 5432,
  ssl: {
    rejectUnauthorized: false,
    key: fs.readFileSync(path.resolve(__dirname, "pg_server.key")).toString(),
    cert: fs.readFileSync(path.resolve(__dirname, "pg_server.crt")).toString(),
  },
};

const pool = new Pool(config);
pool
  .connect()
  .then((client) => {
    console.log("connected");
    // promise
    client
      .query("SELECT * FROM names")
      .then((res) => {
        console.log(res.rows);
        client.release();
      })
      .catch((e) => console.error(e.stack));
  })
  .catch((err) => console.error("error connecting", err.stack))
  .then(() => pool.end());