Deploy - Node/MongoDB

Objectives

• Deploy a MEAN app to a production server using Heroku

• Use the mLab addon and connect to a mLab instance

First, let's deploy the Node app to Heroku.

Deploying the app

• Create a Procfile in the root of your Node application

  • In terminal, run touch Procfile. Must be called with a capitol P

  • make sure it is named "Procfile" (no extention)

  • make sure your Procfile is in the same folder as your index.js file

  • in terminal type echo "web: node index.js" >> Procfile

• In your index.js file, where you get your server started, include the port number in your app.listen function. Example:

app.listen(process.env.PORT || 3000)

This ensures that when we set the PORT config variable, Heroku will run on it instead of the 3000 port (Heroku automatically includes a port that's public-facing).

• Add in your Node version

Note that you may need to specify the node version you're using. To find out what version of node you're using, type the following on your terminal (from anywhere):

node -v

Then, put the following into your package.json file:

"engines": {
    "node": "v11.13.0"
},

• Remove the Heroku-Postbuild script if you are launching a decoupled app.

"scripts": {
    "heroku-postbuild": "There is a bunch of commands here. You can remove this!"
},

• Your package.json file is crucial - when you deploy your application, Heroku will check the package.json file for all dependencies so be mindful to install any dependencies you may have installed globally. You can always check your package.json to see if you are missing anything.

• Before you create your app in Heroku, be sure your project is being tracked via a git repository.

• Create a Heroku app via the command line

heroku apps:create sitename

Where sitename is the name of your app. This will create a url like: http://sitename.herokuapp.com

• Commit and push all your data at this point (git push).

• To push to Heroku, enter the following command

git push heroku master

• In terminal after you deploy your app, type in heroku ps:scale web=1

  • this will scale a dyno up

Connecting to a MongoDB Database

Before connecting the Node app to a MongoDB database, we'll need to install an addon called mLab. mLab is a cloud-hosted MongoDB database service that we can connect to.

In order to add the instance, you can use the Heroku toolbelt by typing this command:

heroku addons:create mongolab:sandbox

This will create a free database instance, limited to 496 MB in storage. Keep this in mind.

Tip: While sandbox mode is a free service, you will unfortunately need to add a credit card to your Heroku account in order to take advantage of this. Please let your instructor know if this is a hardship for you, and alternative grading arrangements will be made.

Configuring Mongoose

After creating the mLab addon, you'll be able to access an environment variable called MONGODB_URI. You'll want to connect to this URI on production. Alter your Mongoose connection to read this environment variable, but use the localhost string if the variable doesn't exist. Below is an example.

mongoose.connect(process.env.MONGODB_URI || 'mongodb://localhost/mydbname');

Connecting to a mLab instance using Robo 3T (or similar)

In order to view the contents of your MongoDB database using a GUI client like Robo 3T, you can use the MONGODB_URI. This URI contains the connection information and credentials needed to connect. You can grab the value of this connection string by typing heroku config or by logging into the Heroku dashboard.