Last time, I talked about finding a pre-made vagrant box that would be useful for rails development. I found one that’s pretty good, but it turns out not to be perfect. I decided to try to write my own Vagrantfile for getting a simpl rails server running on localhost, and I came up with the following success criterion:
No care or feeding. In other words, I could open the vagrant file, and run the following commands straight through and have them just work:
vagrant up --provisionvagrant sshcd /vagrantrails new toy_appcd toy_apprails server
And then in the host machine, browsing to localhost:3000 should show the standard “hello from rails” screen. Anything less than that and I feel like I’m sacrificing the real benefit of Vagrant, namely, a repeatable, portable environment setup.
I am doing this by iterative experiment. I started with a Vagrantfile that was empty except for setting the base image of ubuntu/trusty64.
Each iteration, I run vagrant up --provision, then ssh into the box, then try to start a rails server. If I get an error (or am missing a dependency), I exit the ssh session, edit the Vagrantfile, and reload the vm. Periodically, I destroy the vm to make sure that I’m not dependent on some sequence of shell commands I happened to run.
One thing I’ve found useful is this command:
cp $HISTFILE /vagrant/history.txt
It copies the list of shell commands that I’ve run (since the last time I destroyed the vm) into the shared folder, so I can access them from the host machine. That way, if I manage to do something important while I’m ssh’ed into the box, I can read the steps carefully when I’m trying to figure out how to add them to the Vagrantfile so that they become a repeatable part of the environment.
The following Vagrantfile almost passes the test:
| # -*- mode: ruby -*- | |
| # vi: set ft=ruby : | |
| # All Vagrant configuration is done below. The "2" in Vagrant.configure | |
| # configures the configuration version (we support older styles for | |
| # backwards compatibility). Please don't change it unless you know what | |
| # you're doing. | |
| Vagrant.configure("2") do |config| | |
| config.vm.box = "ubuntu/trusty64" | |
| config.vm.network "forwarded_port", guest: 3000, host: 3000 | |
| # runs as root | |
| config.vm.provision "shell", inline: <<-SHELL | |
| apt-get update | |
| git –version || apt-get install -y git | |
| rails –version || apt-get install -y ruby-railties-4.0 | |
| nodejs –version || apt-get install -y nodejs | |
| SHELL | |
| # runs as non-root user "vagrant" | |
| config.vm.provision "shell", privileged: false, inline: <<-SCRIPT | |
| gpg –keyserver hkp://keys.gnupg.net –recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3 | |
| curl -sSL https://get.rvm.io | bash -s stable –rails | |
| source /home/vagrant/.rvm/scripts/rvm | |
| rbenv install 2.0.0-p353 | |
| rbenv global 2.0.0-p353 | |
| yes | gem update | |
| gem install rdoc | |
| gem install rails pg | |
| if [ ! -d "/vagrant/toy_app" ]; then | |
| (cd /vagrant && rails new toy_app) | |
| fi | |
| (cd /vagrant/toy_app && bundle install) | |
| SCRIPT | |
| end | |
What it’s still missing is that rails server doesn’t quite do what it should; for some reason, running rails server will launch the rails server just fine, but will not enable port forwarding, and for that I need to run bundle exec puma -C config/puma.rb. Next time, I’ll try to figure out why the default commands executed by rails ignore config/puma.rb. Also, there are a few warnings printed to the terminal when I vagrant up -- provision from that file. I haven’t noticed any ill effects yet, but I might still try to chase down the errors in a future post.
Till next time, happy learning!
-Will
