server.js

const express = require('express');
const app = express();
const fileUpload = require('express-fileupload');
const ipfsAPI = require('ipfs-api');
const ipfs = ipfsAPI({host: '0.0.0.0', port: '5001', protocol: 'http'});

let LIMIT_IN_BYTES = 1024 * 100;

app.use(fileUpload({
    saveFileNames: true,
    preserveExtension: true,
}));

app.post('/set', function(req, res) {
    // Check the file is under 100k
    if (!req.files) {
        return res.send({
            success: false,
            error: 'No files were selected to upload in field \'file\'',
        });
    }
    if (req.files.file.data.length > LIMIT_IN_BYTES) {
        return res.json({
            success: false,
            error: `The field 'file' cannot be more than ${LIMIT_IN_BYTES / 1024}kb in size`,
        });
    }

    ipfs.files.add([{
        path: req.files.file.name,
        content: req.files.file.data,
    }], (err, resp) => {
        if (err) {
            return res.send({success: false, error: 'Unable to save file', err});
        }
        // eslint-disable-next-line no-undef
        pinHash(resp[0].hash);
        res.send({success: true, file: {
            path: resp[0].path,
            hash: resp[0].hash,
            size: resp[0].size,
        }});
    });
});

app.get('/get/:hash', function(req, res) {
    var hash = req.params.hash;
    ipfs.files.get(hash, function(err, stream) {
        stream.on('data', (file) => {
            file.content.pipe(res);
        });
    });
});

const PORT = 9000;
const HOST = '0.0.0.0';

app.listen(PORT, HOST);