Ryan Kanno: The diary of an Enginerd in Hawaii

Update

Having been a Capistrano user for a few years, I absolutely love sweet, sweet automation. A few months ago, I wrote a blog about how to use Capistrano to deploy to WebFaction. However, since that post, the winds of change have swept through the Rails and Capistrano community with the release of Rails 2.3 and Capistrano 2.5. WebFaction’s Ruby installation precludes you from taking advantage of these great updates, so I’ve come up with a little update to my previous post.

Learn to Change, Change to Learn

To be able to deploy Rails 2.3 with Capistrano 2.5, we’ll first have to jump through a few hoops. Nice, easy hoops, mind you, but still hoops nonetheless.

Your own Ruby installation

You’ll have to install a custom Ruby installation into your WebFaction home directory. By following Step 1 here, you’ll have a working Ruby 1.8.7 installation and RubyGem 1.3. You’ll need these if you want to deploy a Rails 2.3 application. Also, install a version of Mongrel tied to your Ruby installation.

Note: Typically, I like to install custom installations into ~/opt/local/lib/.

Edit Autostart.cgi

You’ll have to make a few edits to a few files from my previous blog post.

Next, open up your favorite editor of choice (*cough*vi*cough*) and edit the autostart.cgi file. Jump to the end of the file and comment out the following line from my previous blog:

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# os.system('/usr/local/bin/mongrel_rails start -c /home/<webfaction_username>/webapps-releases/<webfaction_app_name>/current -d -e production -P /home/<webfaction_username>/webapps/<webfaction_app_name>/log/mongrel.pid -p <port>')

and change it to the following:

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 os.system('/home/<webfaction_username>/opt/local/lib/ruby1.8/lib/ruby/gems/1.8/bin/mongrel_rails start -c /home/<webfaction_username>/webapps-releases/<webfaction_app_name>/current -d -e production -P /home/<webfaction_username>/webapps/<webfaction_app_name>/log/mongrel.pid -p <port>')

Notice: We’re using the path to Mongrel tied to our custom Ruby installation! This might be different in your installation!

Edit the Capfile

In my previous blog, we placed a custom deploy.rb into the config directory. With the latest version of Capistrano, you no longer need to do this. Rather, place the following into a file called Capfile in the root of your Rails project.

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load 'deploy'
 
set :webfaction_username, "<webfaction_username>"
set :webfaction_db_type, "<webfaction_db_type>"
set :webfaction_db, "<webfaction_db>"
set :webfaction_db_username, "<webfaction_db_username>"
set :webfaction_port, "<webfaction_port (get from autostart.cgi)>"
set :database_yml_template, "database.example.yml"
 
set :application, "test"
set :deploy_to, "/home/#{webfaction_username}/webapps-releases/#{application}"
 
set :scm, :subversion
set :scm_user, "<scm_username>"
set :scm_password, Proc.new { Capistrano::CLI.password_prompt("Subversion password for #{scm_user}: ") }
set :repository, Proc.new { "--username #{scm_user} --password #{scm_password} --no-auth-cache <http://path/to/your/svn/goes/here/>"} 
 
set :user, "#{webfaction_username}"
set :use_sudo, false 
 
set :domain, "<webfaction_domain>"
 
role :app, domain
role :web, domain
role :db,  domain, :primary => true
 
desc "Symlink public to what webfaction expects the webroot to be"
task :after_symlink, :roles => :web do
  run "ln -nfs #{release_path}/public /home/#{webfaction_username}/webapps/#{application}/"
end
 
namespace :deploy do
 
  # Taken from http://jonathan.tron.name/2006/07/15/capistrano-password-prompt-tips 
  # Thanks Jonathan! :)
  desc "Creates the database configuration on the fly"
  task :create_database_configuration, :roles => :app do
    require "yaml"
    set :production_db_password, proc { Capistrano::CLI.password_prompt("Remote production database password: ") }
 
    db_config = YAML::load_file("config/#{database_yml_template}")
    db_config.delete('test')
    db_config.delete('development')
 
    db_config['production']['adapter'] = "#{webfaction_db_type}"
    db_config['production']['database'] = "#{webfaction_db}"
    db_config['production']['username'] = "#{webfaction_db_username}"
    db_config['production']['password'] = production_db_password
    db_config['production']['host'] = "localhost"
 
    put YAML::dump(db_config), "#{release_path}/config/database.yml", :mode => 0664
  end
 
  after "deploy:update_code", "deploy:create_database_configuration"
 
  desc "Redefine deploy:start"
  task :start, :roles => :app do
    invoke_command "/opt/local/lib/ruby1.8/lib/ruby/gems/1.8/bin/mongrel_rails start -c #{deploy_to}/current -d -e production -P /home/#{webfaction_username}/webapps/#{application}/log/mongrel.pid -p #{webfaction_port}", :via => run_method
  end
 
  desc "Redefine deploy:restart"
  task :restart, :roles => :app do
    invoke_command "/opt/local/lib/ruby1.8/lib/ruby/gems/1.8/bin/mongrel_rails restart -c #{deploy_to}/current -P /home/#{webfaction_username}/webapps/#{application}/log/mongrel.pid", :via => run_method
  end
 
  desc "Redefine deploy:stop"
  task :stop, :roles => :app do
    invoke_command "/opt/local/lib/ruby1.8/lib/ruby/gems/1.8/bin/mongrel_rails stop -c #{deploy_to}/current -P /home/#{webfaction_username}/webapps/#{application}/log/mongrel.pid", :via => run_method
  end
end

Now, you should be able to run the standard Capistrano tasks to deploy your application to WebFaction with the latest version of Rails!

Explanation

Basically, the only thing I’ve done is shown you how to update your version of Ruby, RubyGems, Mongrel, and Capistrano to place nicely in WebFaction. This should allow you to run commands like ‘cap deploy:setup’, ‘cap deploy:update’ on your local machine and update your live code on WebFaction’s servers. Nothing too serious going on here! As always, feel free to use, steal, take, and/or copy anything on this blog. Hopefully somewhere, someone on the Interwebs will find these tips handy!

And if you find anything wrong with these scripts, don’t hesitate to leave a comment or email!

Voila! (Enjoy)

Popularity: 21% [?]

Update

If you like to stay on the edge, check out my latest post describing how to use Capistrano 2.5 to deploy Rails 2.3 to Webfaction!

There’s nothing I love more than sweet automation.

After spending the better part of an hour searching the great Googs, there was only a single blog I could find describing how to use Capistrano to deploy to WebFaction. Unfortunately, Justin was describing a Capistrano 1.4 deployment. I found a few posts on the WebFaction forums, but nothing concrete. So after a few hours fiddling with the technology, here’s how I configured my Rails 2.1.1 project to use Capistrano 2.5 to deploy to WebFaction.

Assumptions

Before getting started, I’m going to assume the following:

• I’m assuming you’ve already used the one-click WebFaction goodness to create a brand new Rails application in ~/webapps/<application_name>. If you don’t know what I’m referring to, make sure to check out the Rails and Typo Demo screencast. Make sure you have a domain, application, and website configured.
• I’m also going to assume that your nifty Rails application is safely stored away in either a Subversion or Git repository and you’ve frozen Rails in your application.
• Finally, I’m going to assume you setup your database via WebFaction’s control panel.

Installing Capistrano

The very first thing you have to do is install Capistrano on your local machine by issuing the following command:

$ gem install -y capistrano

After installing Capistrano, the first thing you have to do is to “capify” your local Rails project. Change into your project’s root directory and issue the following command:

$ capify .

This configures your Rails project to play nicely with Capistrano. Two files should’ve been created; Capfile in the project root and config/deploy.rb. The deploy.rb file contains the Rails project application-specific deployment configuration.

Configuring WebFaction

Jumping back to WebFaction, I followed a few of the steps in Justin’s blog. First thing’s first, ssh into your WebFaction account and create a directory called webapps-releases in your home directory. This directory is where we’re going to deploy the application to.

Since you’ve already configured a Rails application at ~/webapps/<application_name>, change into that directory. You should see a standard Rails project with the exception of an extra file called autostart.cgi. Remove everything in the directory except the autostart.cgi file by issuing the following commands:

$ cd ~/webapps/<application_name>
$ mv autostart.cgi ~/
$ rm -rf *
$ mv ~/autostart.cgi .

Once the directory is clear, create a symlink to the log directory that will be in the webapps-releases directory we created earlier.

$ ln -s ~/webapps-releases/<application_name>/shared/log ~/webapps/<application_name>/log

Note: I’m assuming here that the WebFaction app and the Rails application have identical names.

Next, open up your favorite editor of choice (*cough*Vi*cough*) and edit the autostart.cgi file. Jump to the end of the file and comment out the following line:

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# os.system('/usr/local/bin/mongrel_rails start -d -e production -P /home/<webfaction_username>/webapps/<webfaction_app_name>/log/mongrel.pid -p <port>')

and right below it, cut and paste the following:

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  os.system('/usr/local/bin/mongrel_rails start -c /home/<webfaction_username>/webapps-releases/<webfaction_app_name>/current -d -e production -P /home/<webfaction_username>/webapps/<webfaction_app_name>/log/mongrel.pid -p <port>')

Creating your custom deploy.rb

After configuring WebFaction, we have to configure the Capistrano application deployment configuration. On your local machine, find the file config/deploy.rb and replace it with the one below.

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set :webfaction_username, "<webfaction_username>"
set :webfaction_db_type, "<webfaction_db_type>"
set :webfaction_db, "<webfaction_db>"
set :webfaction_db_username, "<webfaction_db_username>"
set :webfaction_port, "<webfaction_port (get from autostart.cgi)>"
set :database_yml_template, "database.example.yml"
 
set :application, "test"
set :deploy_to, "/home/#{webfaction_username}/webapps-releases/#{application}"
 
set :scm, :subversion
set :scm_user, "<scm_username>"
set :scm_password, Proc.new { Capistrano::CLI.password_prompt("Subversion password for #{scm_user}: ") }
set :repository, Proc.new { "--username #{scm_user} --password #{scm_password} --no-auth-cache <http://path/to/your/svn/goes/here/>"} 
 
set :user, "#{webfaction_username}"
set :use_sudo, false 
 
set :domain, "<webfaction_domain>"
 
role :app, domain
role :web, domain
role :db,  domain, :primary => true
 
desc "Symlink public to what webfaction expects the webroot to be"
task :after_symlink, :roles => :web do
  run "ln -nfs #{release_path}/public /home/#{webfaction_username}/webapps/#{application}/"
end
 
namespace :deploy do
 
  # Taken from http://jonathan.tron.name/2006/07/15/capistrano-password-prompt-tips 
  # Thanks Jonathan! :)
  desc "Creates the database configuration on the fly"
  task :create_database_configuration, :roles => :app do
    require "yaml"
    set :production_db_password, proc { Capistrano::CLI.password_prompt("Remote production database password: ") }
 
    db_config = YAML::load_file("config/#{database_yml_template}")
    db_config.delete('test')
    db_config.delete('development')
 
    db_config['production']['adapter'] = "#{webfaction_db_type}"
    db_config['production']['database'] = "#{webfaction_db}"
    db_config['production']['username'] = "#{webfaction_db_username}"
    db_config['production']['password'] = production_db_password
    db_config['production']['host'] = "localhost"
 
    put YAML::dump(db_config), "#{release_path}/config/database.yml", :mode => 0664
  end
 
  after "deploy:update_code", "deploy:create_database_configuration"
 
  desc "Redefine deploy:start"
  task :start, :roles => :app do
    invoke_command "/usr/local/bin/mongrel_rails start -c #{deploy_to}/current -d -e production -P /home/#{webfaction_username}/webapps/#{application}/log/mongrel.pid -p #{webfaction_port}", :via => run_method
  end
 
  desc "Redefine deploy:restart"
  task :restart, :roles => :app do
    invoke_command "/usr/local/bin/mongrel_rails restart -c #{deploy_to}/current -P /home/#{webfaction_username}/webapps/#{application}/log/mongrel.pid", :via => run_method
  end
 
  desc "Redefine deploy:stop"
  task :stop, :roles => :app do
    invoke_command "/usr/local/bin/mongrel_rails stop -c #{deploy_to}/current -P /home/#{webfaction_username}/webapps/#{application}/log/mongrel.pid", :via => run_method
  end
end

Props out to Jonathan for the fantastic Capistrano tips!

After copying the deploy.rb file and editing the appropriate variables, run the following command in your Rails project’s root directory:

$ cap deploy:setup

This command creates the appropriate directory structure for Capistrano on the deployment server based upon values set in your deploy.rb. Next, run the following command to check your dependencies.

$ cap deploy:check

If everything is successful, you should see a message that reads something like…

You appear to have all necessary dependencies installed

Next, push your code out to the server using the following command:

$ cap deploy:update

Finally, to start up your application run the following Capistrano command:

$ cap deploy:start

Now, you should be able to run the standard Capistrano tasks to deploy your application to WebFaction!

Explanation

Most techies like to have an explanation of what’s going on with the Capistrano deploy.rb. I could probably write another blog about it, but I’m lazy (and pressed for time). The :create_database_configuration task basically writes the database.yml production configuration on the fly (courtesy of this blog posting).

The basic gyst of the rest of the script is that WebFaction is proxying a Mongrel instance. The Capistrano deploy.rb override the original deploy:start, deploy:stop, and deploy:restart tasks to run Mongrel commands that WebFaction can understand. Typically, the default Capistrano tasks run script/spin and reaper, but it was easier just to redefine the task. If anyone has any tips/suggestions to improve the script, I’m all ears!

Voila! (Enjoy)

Popularity: 28% [?]

After searching the great Googs and reading here, here, and here about commenting out regions in your RHTML templates, I couldn’t find a (good) solution aside from the (<... if false ...>) paradigm. Using Rails 1.2.3 (I know, I know… we’re old school), to get block comments in Rails, the following worked for me, but unfortunately, still wasn’t recognized by NetBeans 6.0 (Boo!).

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<table>
  ...
  <tbody>
    <tr id="<%= "photographer_#{photographer.id}"%>">
      <td><% 
=begin %>
<%= h photographer.first_name unless photographer.blank? %><% 
=end %>
      </td>
    </tr>
  </tbody>
  ...
</table>

Happy Coding!

Popularity: 49% [?]

Update: 5/24/2009

Update: 12/5/2007

Apparently, I’m still a rookie blogger and I forgot to mention that I was pulling from trunk (-r 8642). Don’t use the tags if you want the code below to work. Sorry about that neilo!

Since my past few blogs have been for the Django community, I’ll switch it up a little and talk about a visualization widget from those uber-smart kids at MIT.

For one of my Rails prototypes at work, I decided to integrate Timeline; a pretty neat DHTML-based AJAXy widget for visualizing time-based events. Using a visual timeline is not only a lot ‘purrrrrtier’ than the mundane list-style displays, but it also gives a better relative perspective of how events overlap, their duration, etc.

In any case, I liked loved it, and I really wanted to use it.

Since I typically don’t have access to the Internet at work (I know, I know… a pseudo-developer without Internet access; welcome to my so-called life), I often have to download libraries and install them locally. Searching Timeline’s mailing list archives, I found one thread concerning the local installation of Exhibit.

Yet, nothing about Timeline.

So with that said, here’s the edits I made (kudos to Firebug developers). I would’ve created a patch file, but I was too lazy and the edits were too easy (sorry). Search for the following line in timeline-api.js (located in src/webapp/api directory in the downloadable distribution).

var url = useLocalResources ?
            "http://127.0.0.1:9999/ajax/api/simile-ajax-api.js?bundle=false" :
            "http://static.simile.mit.edu/ajax/api-2.0/simile-ajax-api.js";

and edit it to the following:

//var url = useLocalResources ?
//            "http://127.0.0.1:9999/ajax/api/simile-ajax-api.js?bundle=false" :
//            "http://static.simile.mit.edu/ajax/api-2.0/simile-ajax-api.js";
var url = (document.location.toString().indexOf('https://') != -1 ? "https" : "http") + "://" + window.location.href.split("/")[2] + "WEB_URL_TO /src/ajax/api/simile-ajax-api.js?bundle=false";

Basically, instead of using the supplied Jetty webserver, we’re just editing the url to your local installation of the file. Remember to change WEB_URL_TO to the path to the simile-ajax-api.js file in your own environment. Typically, one would put this file in a publicly accessible web folder named js, javascript, etc.

Voila!

As an added bonus, nowhere in Timeline’s documentation or examples does it indicate how to load inline event data. When I say inline, I mean dynamic data produced as a result of an action; in this case a search query. I want to be able to query on a set of dates and produce all event data points between those dates. Timeline’s typical use case is to load data from a javascript (.js) file. Personally, since the data is dynamic, I didn’t feel like writing a temp file publicly accessible by the web server or creating a REST action exposing the dynamic data; both of which are viable solutions, the latter more ideal than the former. I just wanted to write JSON inside of the rendered html file and load the Timeline. To do so, instead of coding the following (like in their cubism example):

      tl = Timeline.create(document.getElementById("tl"), bandInfos, Timeline.HORIZONTAL);
      tl.loadJSON("cubism.js", function(json, url) {
           eventSource.loadJSON(json, url);
      });

Using a rails example, this is what I included in my view:

<% if @include_timeline %>
    <%= javascript_include_tag 'PATH_TO/timeline-api.js?timeline-use-local-resources=true' %> 
    <script>
      var tl;
 
      var events = {
        <% if @events %>
        'dateTimeFormat': 'iso8601',
        'events': [
          <% @events.each_with_index do |event, i| %>
          {
            <% if event.start and event.end %>
             'start': '<%= event.start.iso8601 %>',
             'end'  : '<%= event.end.iso8601 %>',
            <% else %>
             'start': '<%= event.occurred.iso8601 %>',
            <% end %>
            'title': '<%= event.headline %>',
            'description': '<%= event.description %>'
          }<% if i != @events.length - 1 -%>, <% end -%>
          <% end %>
        ]
        <% end %>       
      };
 
      function onLoad() {
        var eventSource = new Timeline.DefaultEventSource(); 
        var theme = Timeline.ClassicTheme.create();
        theme.event.label.width = 250;
        theme.event.bubble.width=320;
        theme.event.bubble.height=220;
        var bandInfos = [
          Timeline.createBandInfo({
              width: "20%",
              intervalUnit: Timeline.DateTime.DAY,
              intervalPixels: 100,
              eventSource: eventSource,
              theme:theme
          }),
          Timeline.createBandInfo({
              width: "50%",
              intervalUnit: Timeline.DateTime.MONTH,
              intervalPixels: 100,
              eventSource: eventSource,
              theme:theme
          }),
          Timeline.createBandInfo({
              width: "30%",
              intervalUnit: Timeline.DateTime.YEAR,
              intervalPixels: 200,
              eventSource: eventSource,
              theme:theme
          })
        ];
        bandInfos[1].syncWith = 0;
        bandInfos[2].syncWith = 0;
        bandInfos[2].highlight = true;
        tl = Timeline.create(document.getElementById("timeline"), bandInfos);
        eventSource.loadJSON(events, '');
      }
      var resizeTimerID = null;
      function onResize() {
          if (resizeTimerID == null) {
              resizeTimerID = window.setTimeout(function() {
                  resizeTimerID = null;
                  tl.layout();
              }, 500);
          }
      }
    </script>
  <% end %>

Things that you should take note of:

• I used Ruby’s DateTime iso8601 message to help pass a date that Timeline could understand.
• I called eventSource.loadJSON(events, ”); where I passed in the events JSON array.

Hopefully, these two pointers can help you save some time integrating Timeline into your project! Since this is on my blog, feel totally free to take/use/steal/distribute/copy/modify any code you see fit. All I ask is if you find any bugs, have any comments, or can think of ways to make my ugly code cleaner – I’d love to hear from you.

Enjoy!

Popularity: 41% [?]