hosting.md

Hosting a PSQL DB using Heroku

There are many ways to host applications like the one you have created. One of these solutions is Heroku. Heroku provides a service that you can push your code to and it will build, run and host it. Heroku also allows for easy database integration. Their documentation is excellent, so take a look at that. This document is essentially a more condensed, specific version of the steps described in the Heroku docs.

1. Install the Heroku CLI

On macOS:

brew tap heroku/brew && brew install heroku

...or Ubuntu:

sudo snap install --classic heroku

2. Create a Heroku App

Log into Heroku using their command line interface:

heroku login

Create an app in an active git directory. Doing this in the folder where your server exists is a good start, as this is what you will be hosting.

heroku create your-app-name

Here your-app-name should be the name you want to give your application. If you don't specify an app name, you'll get a random one which can sometimes be a bit iffy.

This command will both create an app on Heroku for your account. It will also add a new remote to your git repository. Check this by looking at your git remotes:

git remote -v

3. Push Your code up to Heroku

git push heroku master

4. Creating a Hosted Database

Go to the heroku site and log in.

• Select your application
• Configure Add-ons
• Choose Heroku Postgres

The free tier will be adequate for our purposes. This will provide you with a postgreSQL pre-created database!

Check that the database exists. Click settings on it, and view the credentials. Keep an eye on the URI. Don't close this yet!

5. Seeding the Production Database

Check that your database's url is added to the environment variables on Heroku:

heroku config:get DATABASE_URL

If you are in your app's directory, and the database is correctly linked as an add on to Heroku, it should display a DB URI string that is exactly the same as the one in your credentials.

At the top of your knexfile.js, add the following line of code:

const { DB_URL } = process.env;

Then add a production key to the customConfigs object:

const { DB_URL } = process.env;
// ...
const customConfigs = {
  // ...
  production: {
    connection: `${DB_URL}?ssl=true`,
  },
};
// ...

It is critical to add the query of ssl=true, otherwise this will not work!

In your ./db/data/index.js add a key of production with a value of your development data in your data object. Something like:

const data = { test, development, production: development };

This is will ensure your production DB will get seeded with the development data.

In your package.json, add the following keys to the scripts:

{
  "scripts": {
    "seed:prod": "NODE_ENV=production DB_URL=$(heroku config:get DATABASE_URL) knex seed:run",
    "migrate-latest:prod": "NODE_ENV=production DB_URL=$(heroku config:get DATABASE_URL) knex migrate:latest",
    "migrate-rollback:prod": "NODE_ENV=production DB_URL=$(heroku config:get DATABASE_URL) knex migrate:rollback"
  }
}

Each of these will establish an environment variable called DB_URL, and set it to whatever heroku provides as your DB URL. It is essential that you do this as the DB URL may change! This deals with a lack of predictability on heroku's end.

Make sure to run the seed prod script from your package.json:

npm run seed:prod

6. Connect To The Hosted Database when on Heroku

Change your connection file to look something like this:

const ENV = process.env.NODE_ENV || 'development';
const knex = require('knex');

const dbConfig =
  ENV === 'production'
    ? { client: 'pg', connection: process.env.DATABASE_URL }
    : require('../knexfile');

module.exports = knex(dbConfig);

It should check whether you're in production, and if you are, it should connect to the production database. Otherwise it will connect to the (.gitignore'd) knex file.

7. Use Heroku's PORT

In listen.js, make sure you take the PORT off the environment object if it's provided, like so:

const { PORT = 9090 } = process.env;

app.listen(PORT, () => console.log(`Listening on ${PORT}...`));

8. Add a start script

Make sure your package.json has this as a start script:

"start": "node listen.js",

Commit your changes, and push to heroku master.

git push heroku master

9. Review Your App

heroku open

Any issues should be debugged with:

heroku logs --tail