Server-Side Development with Hapi.js — File Names, Composing Server Parts, and Process Monitor

Hapi.js is a small Node framework for developing back end web apps.

In this article, we’ll look at how to create back end apps with Hapi.js.

File Utility

We can generate a file path from path segments with the @hapi/file module.

For example, we can write:

const Hapi = require('@hapi/hapi');
const file = require('@hapi/file');

const init = async () => {
  const server = new Hapi.Server({
    port: 3000,
    host: '0.0.0.0'
  });

  server.route({
    method: 'GET',
    path: '/',
    handler(request, h) {
      const fileName = file.uniqueFilename('/root', '.txt');
      return fileName
    }
  });

  await server.start();
  console.log('Server running at:', server.info.uri);
};

process.on('unhandledRejection', (err) => {
  console.log(err);
  process.exit(1);
});
init();

We call the file.uniqueFilename method to create a unique file name.

We should get something like:

/root/1604965754941-1144-2fbcec5c8927e564.txt

returned as the response.

Compose Different Server Components

We can use the @hapi/glue module to compose different server components.

To use it, we write:

index.js

const Hapi = require('@hapi/hapi');
const Glue = require('@hapi/glue');

const manifest = {
  server: {
    port: 3000,
    host: '0.0.0.0'
  },
  register: {
    plugins: [
      {
        plugin: require('./my-plugin'),
        options: {
          uglify: true
        }
      },
    ],
  }
};

const options = {
  relativeTo: __dirname
};

const init = async () => {
  const server = await Glue.compose(manifest, options);

  server.route({
    method: 'GET',
    path: '/',
    handler(request, h) {
      return 'hello'
    }
  });

  await server.start();
  console.log('Server running at:', server.info.uri);
};

process.on('unhandledRejection', (err) => {
  console.log(err);
  process.exit(1);
});
init();

my-plugin.js

const myPlugin = {
  name: 'myPlugin',
  version: '1.0.0',
  async register (server, options) {
    server.route({
      method: 'GET',
      path: '/test',
      handler (request, h) {
        return 'hello, world';
      }
    });
  }
};

module.exports = myPlugin

We created a plugin with one route within the my-plugin.js file.

Then in index.js , we have our manifest object with the server options.

register is a property with the plugin properties inside.

The plugins array has an array of plugins we want to register.

options has extra options we want to set for our server.

Then we compose everything together with the Glue.compose method.

It returns the Hapi server object which we can use to add more routes with the server.route method.

Process Monitor

We can add a simple process monitor to our Hapi app with the @hapi/good module.

To add it, we write:

const Hapi = require('@hapi/hapi');

const init = async () => {
  const server = new Hapi.Server({
    port: 3000,
    host: '0.0.0.0'
  });

  await server.register({
    plugin: require('@hapi/good'),
    options: {
      ops: {
        interval: 1000
      },
      reporters: {
        myConsoleReporter: [
          {
            module: '@hapi/good-squeeze',
            name: 'Squeeze',
            args: [{ log: '*', response: '*', ops: '*' }]
          },
          {
            module: '@hapi/good-console'
          },
          'stdout'
        ]
      }
    }
  });

  server.route({
    method: 'GET',
    path: '/',
    handler(request, h) {
      return 'hello'
    }
  });

  await server.start();
  console.log('Server running at:', server.info.uri);
};

process.on('unhandledRejection', (err) => {
  console.log(err);
  process.exit(1);
});
init();

We add the reporters property to add a logger for monitoring resource usage.

We add the @hapi/good-squeeze module to add the items to log with the args array.

log has the timestamp, response has the HTTP response returned, and ops has the resource usage.

The @hapi/good-console lets us log the numbers to the console.

Conclusion

We can add various modules to our Hapi app to monitor resource usage, generate file names, and compose server components.