Deploying to Heroku

What is Heroku

Heroku is a popular all in one hosting solution, you can find more at heroku.com

Signing Up

You’ll need a heroku account, if you don’t have one, please sign up here: https://signup.heroku.com/

Installing CLI

Make sure that you’ve installed the heroku cli tool.

HomeBrew

brew install heroku/brew/heroku

Other Install Options

See alternative install options here: https://devcenter.heroku.com/articles/heroku-cli#download-and-install.

Logging in

Once you’ve installed the CLI, login with the following:

heroku login

Create an application

Visit dashboard.heroku.com to access your account, and create a new application from the drop down in the upper right hand corner. Heroku will ask a few questions such as region and application name, just follow their prompts.

Project

Today we’re going to be hosting Swift NIO’s example http server, you can apply these concepts to your own project. Let’s start by cloning NIO

git clone https://github.com/apple/swift-nio

Make sure to make our newly cloned directory the working directory

cd swift-nio

By default, Heroku deploys the master branch. Always make sure all changes are checked into this branch before pushing.

Connect with Heroku

Connect your app with Heroku (replace with your app’s name).

$ heroku git:remote -a your-apps-name-here

Set Stack

As of 13 September 2018, Heroku’s default stack is Heroku 18, we need it to be 16 for swift projects.

heroku stack:set heroku-16 -a your-apps-name-here

Set Buildpack

Set the buildpack to teach Heroku how to deal with swift, the vapor-communnity buildpack is a good buildpack for any swift project. It doesn’t install vapor, and it doesn’t have any vapor specific setup.

heroku buildpacks:set vapor/vapor

Swift version file

The buildpack we added looks for a .swift-version file to know which version of swift to use.

echo "5.2" > .swift-version

This creates .swift-version with 5.2 as its contents.

Procfile

Heroku uses the Procfile to know how to run your app. This includes the executable name and any arguments necessary. You’ll see $PORT below, this allows heroku to assign a specific port when it launches the app.

web: NIOHTTP1Server 0.0.0.0 $PORT

You can use this command in terminal to set the file

echo "web: NIOHTTP1Server 0.0.0.0 $PORT" > Procfile

Commit changes

We have now added the .swift-version file, and the Procfile, make sure these are committed into master or Heroku will not find them.

Deploying to Heroku

You’re ready to deploy, run this from the terminal. It may take a while to build, this is normal.

git push heroku master