# Deploy - Rails

## Objectives

* Deploy a Rails app to a production server using Heroku

Deploying a Rails app (like all things in Rails) is simple and magical.

## Prepare for deployment

If your app is **already using postgres** all you have to do is add the `12factor` gem to your Gemfile in the production group.

**Anywhere in Gemfile**

```ruby
gem 'rails_12factor', group: :production
```

This gem takes care of producing descriptive logs and serving your assets. Based on the recommended read: [The Twelve-Factor App](http://12factor.net/). Note that this class has covered many of these principles.

### Bundle

Once this is done you have to run `bundle` which will automatically update the `Gemfile.lock`, which must be done before you push to Heroku. Be sure to commit your changes before pushing.

## Pushing to Heroku

If you haven't already, download the [Heroku toolbelt](https://toolbelt.heroku.com/), which is a commandline tool used to interact with your heroku instance.

### Create a heroku app

First you need to create a heroku app (if you haven't already). This can be done in the command line inside your project directory.

```ruby
heroku create YOUR_APP_NAME_HERE
```

You can test that this worked by running `git remote -v` and you should see a new remote for heroku. If not try again (**pay attention** to any error messages).

### Push it... p-p-p-push it real good

Once that is done we are ready to push our site to heroku. First, run `git status` to make sure you've added and commited all changes then we just push to the newly added heroku remote.

```
git push heroku master
```

(this will take a while to complete)

## Production Database Setup

You can run any command on heroku by using `heroku run` followed by the command you want to execute. This will work for any command you'd normally run on your local development environment. This means that we can run `rake db:migrate` on the server.

**migrate the database**

```
heroku run rake db:migrate
```

You can also run `db:reset` or `db:seed` if you need to reset your database.

## Configure environment variables

If your app depends on any environment variables (if you have a `.env` file) you'll need to set those values on Heroku.

To see the currently set environment values run

```
heroku config
```

To set a value run

```
heroku config:set TACO_KEY=xxxxxxx
```

## Viewing your site

Once the push finishes you can go to your website. If you run `heroku open` it will automatically load your web browser at the appropriate URL.

## Updating

Once everything is set up all you have to do is run `git push heroku master` to push new changes to Heroku (always make sure your changes are commited with `git status`).

## Troubleshooting

**What if something goes wrong?**

From your project directory you can run `heroku logs` to see the rails console output on heroku or `heroku logs --tail` to see a live feed.

You can also type `herkou run rails c` to access the rails console on the production server.


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