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You have completed Deploy a Node Application to Heroku!
You have completed Deploy a Node Application to Heroku!
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Now you know what Heroku is, let's get our application ready and deploy it!
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Now you have
the Heroku Toolbelt installed,
0:00
it's now time to deploy our application.
0:03
Let me show you what the application is.
0:06
It's a simple HTTP server, but
0:11
just says Hello World no
matter where you navigate to.
0:13
Heroku users get to deploy applications.
0:20
So if you haven't got your
application checked since the git,
0:24
which you should have by now,
you need to do that.
0:27
My application is already committed.
0:30
Just committing your application to
git is not enough to deploy to Heroku.
0:37
There's a couple of things you need to
do to prepare your app for deployment.
0:42
Make sure you have a package.json file.
0:47
Because Heroku doesn't know which version
of Node you've been developing for,
0:50
you need to specify what version of
Node.js that Heroku will install and
0:54
use for your application.
0:59
You need to have a special file
at the root of your application
1:01
that will let Heroku know
how to run your application.
1:05
I'll go into more detail
about this file shortly.
1:09
Then create the application on
Heroku using the Heroku Toolbelt.
1:12
This will link your Heroku application
as a remote git repository too.
1:16
Each Heroku application is stored in
virtual machine containers called dinos.
1:21
Each dino has its own
configuration settings, for
1:26
example, the port number that
it routes web traffic to.
1:29
There's a way you can
programmatically access this, and
1:32
I'll show you that in a minute.
1:35
Let's first create a package.json file.
1:37
We do this by using npm init.
1:40
A package.json file helps manage
dependencies for your project,
1:45
whether if it's an application or
an npm package.
1:50
Now there's no dependencies for
this application.
2:02
But there is one dependency that you don't
normally see in a package.json file,
2:05
unless you're deploying it to Heroku,
and that's engines.
2:09
The engines key is to tell Heroku
which version of node.js to use when
2:24
running our application.
2:29
As of this recording,
the latest long term support version of
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node.js is 4.2.4, so let's use that.
2:36
Next we need to tell Heroku how
we need to run our application.
2:51
We run our application with node app.js.
2:55
Heroku uses a special file called
a procfile or a process file.
3:01
A process is a running application.
3:08
You can tell Heroku any
number of processes.
3:12
In this case, you'll need at least one for
the web server.
3:14
You first start with the name of
your process followed by a colon,
3:19
then the command you
want the process to run.
3:24
Let's commit our changes.
3:32
Next, let's create
the application on Heroku.
3:48
You'll need to log into Heroku if you
haven't already with Heroku log in.
3:52
If you haven't used it before,
you may see a screen like this.
4:01
Don't worry.
4:05
Fill in your credentials,
and you should be logged in.
4:06
Heroku Toolbelt is a command line
utility to help you manage your
4:16
applications using commands.
4:21
Type heroku help to see
a list of command topics.
4:23
See, there's an apps topic,
used to manage applications, create and
4:34
destroy them, for example.
4:38
To see a list of commands in that
topic area, type heroku help apps.
4:40
The first command is Heroku apps:create,
with an optional application name.
4:47
If you don't include a name,
they'll generate one for you.
4:56
The application name translates to a
subdomain to access your replication app.
5:00
If you don't want something random,
choose something yourself.
5:05
I choose helloworld-treehouse.
5:13
Since I picked this name, no one else can.
5:20
During the application creation process,
5:23
Heroku adds a new remote repository to
your git repository on your local machine.
5:25
An example of another remote
repository is a GitHub repository.
5:31
This is typically called origin.
5:36
When you do git push origin master,
it pushes everything from
5:38
your master branch on your local machine
to the master branch on GitHub the origin.
5:44
With Heroku,
it creates a remote called heroku.
5:50
So to deploy to Heroku,
you can simply do git push, heroku master.
5:54
But what you want to do before deploying
to Heroku is test that it runs locally.
6:02
To do this,
you use the heroku local command.
6:11
If you notice,
it says it's running on port 5000.
6:19
However, our application
runs on port 1337.
6:22
There is a disconnect.
6:26
If you try and visit 5000,
it's not there, but 1337 is.
6:30
Heroku expects that your application
coding will handle an environmental
6:38
variable called port.
6:42
An environment variable is a variable that
can be accessed by the process and used.
6:44
Heroku local sets up the port
environment variable
6:49
just like it does in the Heroku
live hosted environment.
6:52
Just simply put process.env.port
6:59
followed by the or operator and
7:04
then the default port of your choosing.
7:08
What this code does is it sets the port
to whatever the environment variable is.
7:14
If there isn't one,
it will set it to 1337.
7:20
If we terminate the process with Ctrl+C,
when we do heroku
7:25
local now, it correctly runs at port 5000.
7:31
If we kill this process
again with Ctrl+C and
7:37
directly run the app with node app.js,
it will run
7:41
on port 1337, since we're not running it
in an environment where the port is set.
7:47
Finally, we can commit our changes.
7:53
We can push them using
git push heroku master.
8:09
It's now deployed on Heroku.
8:21
If your code is on GitHub,
8:23
you probably want to deal with
git push origin master right now.
8:25
We can now visit our
applicationname.herokuapp.com or
8:29
type heroku open to open
it up in a web browser.
8:34
No!
8:41
There is an error with our application,
and this is a common gotcha.
8:41
It may work on your local environment,
but it may not work on Heroku.
8:46
And the reason is this.
8:50
Now, the reason it doesn't work on Heroku,
but
8:52
it does on our local machine is
because we're using a hostname here.
8:55
So let's just remove these because
hostname is actually optional, so
8:59
it will still work on our local machine,
and in theory, it should work on Heroku.
9:04
So let's save our file.
9:10
And do git status, and
we've only modified our app so
9:14
let's do git add, git commit -m "Removed
9:20
hostname", git push heroku master.
9:26
When we do heroku open now, it works.
9:37
Cool.
9:40
And that's it.
9:41
For further reading,
9:42
check out Getting Started with
Node.js on Heroku's Dev Center.
9:43
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