Yet a simpler way of deploying... deploying a rails app with dokku
There are so many ways of deploying an application, in this short post I would like to walk you through deploying using dokku, a simple and light PaaS tool.
TL;DR
# Get a server with dokku installed (learn how to with http://dokku.viewdocs.io/dokku/getting-started/installation/#1-install-dokku)
# Tip: use DigitalOcean dokku image to make set up easier
ssh root@your-server-ip
# Create app and initialize git
dokku apps:create your_app
dokku git:initialize your_app
# Set up any environment variables required
dokku config:set --no-restart your_app RAILS_MASTER_KEY=...
# Enable and set up domain
dokku domains:enable your_app
dokku domains:set your_app your.domain.com
# Install let's encrypt plugin
# to generate a ssl certificate
sudo dokku plugin:install https://github.com/dokku/dokku-letsencrypt.git
# Generate ssl certificate
dokku config:set --no-restart your_app DOKKU_LETSENCRYPT_EMAIL=your@email.com
dokku letsencrypt your_app
# Enable ssl auto renew
dokku letsencrypt:cron-job --add
# In your local machine
git remote add dokku dokku@your-server-ip:your_app
git push dokku master
dokku
I’m sure you are familiar with Heroku, and dokku is just that, a tool quite similar to Heroku, but open source and free of charge. If you don’t know Heroku, it’s just a platform to make deployments easier, but of course, at a heavy price.
Quick test
Let’s deploy a rails application to see how this puppy behaves. First of all, we need a server. I’m using DigitalOcean since it’s cheap, works well and most importantly, it comes with a pre-installed dokku image when setting up the instance. If you wan to install it manually, you can follow the instructions on how to install dokku.
After creating the instance, go ahead and ssh into it. Let’s make sure dokku is
installed with dokku help.
If dokku is installed, we can begin with the process. Go ahead and create a new
application with dokku apps:create your_app. Great, now, we want to deploy
using git, on every push we do. In order to do that, we need to run
dokku git:initialize your_app. Now, go to your local machine, cd into your
project and add a new remote host with git remote add dokku dokku@ip:your_app.
Environment variables
Since we are using rails for this example, we need to set the
RAILS_MASTER_KEY. We can set environment variables with
dokku config:set --no-restart your_app KEY=VALUE. With that, we can set our
secret key dokku config:set --no-restart your_app RAILS_MASTER_KEY=....
First dummy deploy
Go ahead and run git push dokku master. This should trigger the deployment
process. After that, we are ready to set up the domain and ssl certificate.
Domain & SSL
Again, 2020, we need https and boy, up until now, this is the easiest way I have found to set the certificate up.
First, we need to set up the domain for our app. Enable domains with
dokku domains:enable your_app, then run dokku domains:set your_app your.domain.com
Once we got the domain configured, we can continue with SSL. In order to set up the certificate, we will be using a dokku plugin that makes the whole process very easy.
sudo dokku plugin:install https://github.com/dokku/dokku-letsencrypt.git
dokku config:set --no-restart your_app DOKKU_LETSENCRYPT_EMAIL=your@email.com
dokku letsencrypt your_app
dokku letsencrypt:cron-job --add
That’s it
Done. Your certificate should be set up and it will auto renew. If you go to
https://your.domain.com (after setting up the DNS, so your domain points
to your instance), you should see the app running.
Remote commands
Probably you want to be able to run some these commands but from your local machine (for example to set up environment variables). In order to do that, you have to install the dokku client. Once installed, you can cd into your project’s folder and use it:
dokku proxy:report
=====> your_app proxy information
Proxy enabled: true
Proxy port map: http:80:5000 https:443:5000
Proxy type: nginx
Notice I didn’t included the app_name, that’s because dokku is smart enough to pick that up from the git remote configuration :)