How to Deploy Node.js Apps on DigitalOcean with Dokku

Matthew Palmer February 19, 2014

DigitalOcean is a great place to host your web apps, being cheaper than other, managed services like Nodejitsu or Heroku. It has a $5/month plan, and using the DigitalOcean promo code OMGSSD10 gives you $10 credit (two months) for free to try it out. This might expire, so Google for promo codes if it has.

Nodejitsu and Heroku justify their higher pricetag by offering better support and ease of deployment—the former is hard to gauge, but the complexities of the latter, when using DigitalOcean, can be mitigated thanks to Dokku.

Dokku is an awesome abstraction of Docker. Basically, Dokku provides a better interface to app deployment, comparable to the offerings of Heroku and Nodejitsu. It works for any VPS, but I like DigitalOcean. Here is a guide on how to set up and deploy your first application to DigitalOcean using Dokku.

Sign up

Sign up for DigitalOcean.

Add a credit card—I would love to not have to do this, but they don’t charge you. Don’t forget to use the free promo code.

SSH Keys

Click SSH Keys in the sidebar. Setting up an SSH key first isn’t mandatory, but it’s better in the long run.

In your local Terminal, change into your ~/.ssh directory.

cd ~/.ssh

Generate an SSH key. Note: I didn’t use the default /Users/username/.ssh/id_rsa because I prefer to name my SSH keys more explicitly. I recommend saving it to /Users/username/.ssh/id_rsa_digitalocean_appname—the rest of the guide assumes the keys are saved to this location.

ssh-keygen -t rsa -C "[email protected]"

Enter a passphrase if you want. Copy the public key contents to your clipboard.

cat ~/.ssh/id_rsa_digitalocean_appname.pub | pbcopy

Click Add SSH Key at the top of the DigitalOcean SSH Key page. Paste the contents in. Name it something explicit.

The Droplet

We now have to create a new Drop on the DigitalOcean website.

• Click Create Droplet on the DigitalOcean website.
• Enter a hostname.
• Select the plan you want.
• Select a region.
• Under Select Image, click the tab for Applications and choose Dokku-v....
• Select the SSH key you created before.
• Click Create Droplet.

Initial Access

SSH into your new Droplet. Your IP address is available from the DigitalOcean website; it’s in the top information bar.

ssh [email protected]

If prompted, enter the password emailed to you. You might have to have your password reset and then emailed to you. Do this from the Access tab in the main DigitalOcean web interface.

After a few seconds, you’ll be running commands on the remote Droplet.

Visit the Droplet in your web browser by opening YOUR.DROPLET.IP.ADDRESS.

Everything should be configured properly by default, but if it isn’t, you can change your settings here. Hit Finish Set up.

Configuring The App

Create a garden-variety Node.js application, such as the Hello World example on the Node.js homepage. You can also use your own.

We need to create a Procfile in the root of your application directory.

touch Procfile && open Procfile

Add the command to run the application (or whatever your main app file is) to the Procfile

web: node app.js

Create a package.json file. I used npm init and followed the interactive prompt.

npm init

Here is the result, which you can use as an example package.json:

{      
    "name": "YOUR-APP-NAME", 
    "version": "0.0.0",      
    "description": "",      
    "main": "app.js",      
    "scripts": {        
        "test": "echo \"Error: no test specified\" && exit 1"      
    },      
    "author": "",
    "license": "BSD-2-Clause" 
}

Initialise a git repository in this directory, add and commit your changes.

git init && git add -A && git commit -m "Initial commit"

Replicate your public SSH Key on your Droplet.

cat ~/.ssh/id_rsa_digitalocean_appname.pub | ssh [email protected] "sudo sshcommand acl-add dokku YOUR-APP-NAME"

If you used the non-default (i.e. anything other than ~/.ssh/id_rsa) location for the SSH Key (I used /Users/username/.ssh/id_rsa_digitalocean_appname), then you need to adjust your SSH config file.

open ~/.ssh/config

Add information so that git knows where the proper SSH Keys are saved. Remember to change both the IP ADRESS and the SSH Key location.

Host YOUR.DROPLET.IP.ADDRESS
    IdentityFile ~/.ssh/id_rsa_digitalocean_appname

Add the remote production server to the git repository.

git remote add production [email protected]:YOUR-APP-NAME

Deployment

Push the app to the production Droplet

git push -u production master

On Mac OS X, if you set a passphrase for the SSH key, you might be asked to enter your password. Do that.

If successful, your last lines of output will be

----->Application deployed: 
    http://YOUR.DROPLET.IP.ADDRESS:PORT

You now need to tell the app to run. SSH into your Droplet.

ssh [email protected]

Change into your application directoy.

cd /home/dokku/YOUR-APP-NAME

Tell the application to run.

dokku run YOUR-APP-NAME node app.js

You should now be able to access your application by visting YOUR.DROPLET.IP.ADDRESS:PORT in your web browser.

If something doesn’t work, or if you have trouble, feel free to contact me on Twitter.