Implement file upload on Express with postgres integration

Author: jitli98

.gitignore

@@ -2,3 +2,5 @@
 .env
 
 node_modules/
+
+tmp/

README.md

@@ -14,9 +14,11 @@ Copy the .env.sample file to a .env file and fill in the missing values
   - The .env file should not be checked into the repository, it contains production secrets!
   - When starting up, the server will read the database credentials/other info from the .env file.  
 
-Run `npm run knex seed:run` to setup the initial database state  
+Run `npm run knex seed:run` and  `npm run knex migrate:latest` to setup the initial database state  
 Run `npm run start` to start the server
 
+
+
 ### Setup Postgres
 These are some helpful tutorials:
 - https://blog.logrocket.com/setting-up-a-restful-api-with-node-js-and-postgresql-d96d6fc892d8/

package-lock.json

@@ -5,7 +5,8 @@
   "main": "src/server.js",
   "scripts": {
     "knex": "knex --knexfile ./src/database/knexfile.js",
-    "start": "node src/server.js"
+    "start": "node src/server.js",
+    "setup": "npm run knex seed:run & npm run knex migrate:latest"
   },
   "author": "Vedant Roy",
   "license": "ISC",
@@ -14,6 +15,7 @@
     "express": "^4.17.1",
     "find-config": "^1.0.0",
     "knex": "^0.20.10",
+    "multer": "^1.4.2",
     "pg": "^7.18.2"
   },
   "devDependencies": {}

package.json

@@ -0,0 +1,17 @@
+// NOTE TO DEVS:
+// You can also run "npm run knex migrate:down file_migrate.js" to drop the table
+// if you run into any issues.
+
+// Adds a files table that has a relation with the user table
+exports.up = async (knex) => {
+    return await knex.schema.createTable('files', (table) => {
+        table.string('filename');
+        table.binary('file');
+        table.string('username');
+    });
+}
+
+// Drops the files table    
+exports.down = async (knex) => {
+    return await knex.schema.dropTable('files');
+}

src/database/migrations/file_migrate.js

@@ -0,0 +1,42 @@
+const fs = require('fs');
+const knex = require('../database/database');
+const multer = require('multer');
+const router = require('express').Router();
+
+const dir = "\\tmp";
+
+let storage = multer.diskStorage({
+    // file uploaded is stored in local directory
+    destination: (req, file, cb) => {
+        const uploadDir = "\\tmp/uploads/"
+        // create a new local directory if it did not already exist
+        fs.exists(uploadDir, exist => {
+            if (!exist) {
+                return fs.mkdir(uploadDir, {recursive: true }, err => cb(err, uploadDir));
+            }
+            return cb(null, uploadDir);
+        });
+    },
+    filename: (req, file, cb) => {
+        cb(null, Date.now() + '-' + file.originalname);
+    }
+});
+
+let upload = multer({ storage: storage });
+
+// [base] = localhost:[port]/files
+// POST [base]/upload/[a username] attached with a file that has fieldname:'myfile'
+// to upload an arbitrary file to the database
+router.post('/upload/:user', upload.single('myfile'), async (req, res, next) => {
+    try {
+        let username = req.params.user;
+        let path = req.file.destination + req.file.filename
+        await knex.raw('INSERT INTO "files" VALUES (?, pg_read_binary_file(?), ?)',
+                        [req.file.filename, path, username]);
+        res.send("Succesfully uploads file");
+    } catch (error) {
+        console.log(error);
+    }
+});
+
+module.exports = router;

src/routes/files.js

@@ -2,6 +2,7 @@ const express = require('express')
 const app = express()
 
 app.use('/users', require('./routes/users'))
+app.use('/files', require('./routes/files'))
 
 const port = 8080
 app.listen(port, () => console.log(`Server listening on port ${port}.`))