Signal is a continuous integration server written in Rails which I think takes the best features of similar systems and merges them in a very simple to use application.

When I started working with Rails, the first continuous integration server I tried was CruiseControl.rb. The CC.rb was also written in Rails and what bothers me the most about it is that to add a project you have to connect to the server and execute:

./cruise add [project-name] -r [repository] -s [svn|git|hg|bzr]

After running the previous command you can open a YAML file and configure the recipient of the emails that are sent by the application when the build breaks. In the scaffolding land, this makes no sense to me. It’s much more simpler to have a page where any user can register a project without much difficulty, like Hudson, Integrity and Signal does.

Another thing that bothers me about CC.rb is that it creates a lot of cruise processes and sometimes they hang. For a while I thought the problem was only happening with me but after talking with some people I found it wasn’t so uncommon.

The third thing I’ll complain about CC.rb is that at the home page it shows the last five builds of each project. IMHO the last two builds is already too much information. To know that the old builds were broken or not doesn’t mean anything to me. The only thing I care about is to know if the project is in a good state or not, information that Integrity and Signal display very well.

Integrity does a lot of things in a cool way, but I don’t like the fact that to install it you have to download the gem and then execute a command. The worst thing is that depending of the server you want to use, the command takes different parameters. Before explaining why this installation method is a problem, let me confess that another thing I don’t like about Integrity is that it doesn’t come with email support. Besides this lack of support be ugly, to include it you have to download another gem and modify a file. It looks simple but didn’t work for me, apparently because the version of the plugin gem was not compatible with the version of the application gem. Now, how do you change the version of an application that was installed by executing a command from a gem? Would it only require to download the second version of the gem and delete the first? Would it require to reinstall the application? I don’t know, maybe I did something stupid but nothing worked for me and this is why I believe that this way of dealing with applications is a problem.

Signal tries to take advantage of Git. To install Signal you can run:

git clone git://github.com/dcrec1/signal.git
cd signal
rake inploy:local:setup

If you ever want to go back to an specific version you just can git reset –hard COMMIT; simple, and it can take advantage of history by knowing where we are and what we are undoing.

One characteristic CC.rb has and I miss in Integrity is to show the date of each build on the home page. Signal shows how long ago each project was built, so we can easily know when was the last build and if they are being created.

report_card is a project that integrates metric_fu with Integrity, but it’s necessary to install another application and run a few commands, what is very complicated to me. It’s for this reason I decided that Signal has native integration with metric_fu, RSpec and Cucumber.

Signal’s integration with RSpec, Cucumber and metric_fu is very simple. In each project page there are three links: specs, features, and metrics, which point to ROOT/docs/specs.html, ROOT/docs/features.html and ROOT/tmp/metric_fu/output/index.html, metric_fu’s default path. This means that if we are generating HTML specifications, they can be accessed from the project page.

Another integration that Signal has is with Inploy. If we want to deploy an application, we can do it from the project page by clicking on deploy, the rake task inploy:remote:update will be executed.

Hudson is an very good integration server, but I think Signal overcomes it by being a little more simpler to use and by being developed in Rails and being hosted on GitHub.

Being developed in Rails is an advantage because this type of projects usually have several plugins and Rails has native support to plugins. Almost every railer knows how to install a plugin and how do they work, so it will not be a problem to create them.

Being on GitHub is an advantage because it facilitates further collaboration with the project. As today, Signal has a lot of conventions, but if for some reason anyone need some special configuration, he can fork the project and start contributing. Since Signal was developed with Rails and it’s pretty simple, people will not have difficulties to understand how it works.

One of the conventions of Signal is that each build is created by running the rake task build, which depending of the project I have something like this:

task: build => ['db:migrate', :spec, :cucumber, 'metrics:all']

I recorded a short video of nearly three minutes demonstrating how easy it is to install and use Signal. In the video I download the application and install it using Inploy. Then I register a new project and create a new build. The build is not automatically created along with the project because sometimes we need to perform some actions before running it. Just for demonstration purposes, I chose a project in Ruby that has a very fast build, given it does not run the Cucumber features neither the metrics. After the first build, I do start delayed_job and create a build from the command line, like being in a Git hook. The video ends with me showing a build of the project Signal and how easily it is to view the specs, the stories and metrics from the project page.

Really easy integration with continuous Signal from Diego Carrion on Vimeo.

If you liked Signal, please consider to recommend at Working With Rails.

After working in some systems made in Rails, Capistrano became one of the things that began to bother me more and more. I tried to find other alternatives, including Vlad, but none satisfied me, so I decided to create a solution and called it Inploy.

Before Capistrano fans crucify me, I wanted to let it clear that I don’t think Capistrano is a bad tool, just that it’s bad for my needs, which are much simpler than Capistrano can attend.

One of the things I don’t like about Capistrano is that it creates a lot of folders, one for each release. Some people argued with me that they are useful when you want to rollback a release, but that never happened to me, as never happened with most of the people I talked with. The rest of the people told me that in some circumstance they had to rollback a deploy, but the circumstance was that the deployed code broke the build.

Inploy uses Git, so in case we need to rollback our deploy to a version, we can use git reset. Of course this solution is more limited that the one that Capistrano uses, but it’s a solution to a problem that probably should never occur, a problem caused probably by bad practices in the development.

As a consequence of Capistrano strategies, they deploys are a little slow for my taste. I know there are some configurations that can speed up the process, but to configure is a thing I don’t want to do. I want to use a tool that works the best way by default and in most cases, the best way to a fast deploy is the simplest one: git clone in the setup and git pull in the update, the same that Inploy does.

Speaking about defaults, it’s very annoying to me having to define in Capistrano how to restart the server, how to clean the cache and what tasks it should rake, like more:parse and asset:packager:build_all. Inploy tries to solve this problems by executing common tasks by default, being smart enough to identify what tasks it should rake and in which order. The idea behind the plugin is that you shouldn’t worry about how to deploy that new tool you’re using, that things just work without the possibility of something going wrong.

Another advantage from Inploy over Capistrano for most cases is that it just have one way to deploy and its called update. This task updates the code, migrates the database, does some other tasks and restarts the server. It makes not sense to me to update the code without running migrations. In all teams I worked with, everyone could deploy the application and in most cases someone executed cap deploy instead of cap deploy:migrations. I know this is a human error but I prefer to use a tool that doesn’t let people make mistakes.

A need I had with deployment tools is that it could work both remotely and locally. I worked in a project that was delivered to a foreign client and the people responsible of updating the application in each release couldn’t do it otherwise that by connecting to a server and running a script. All of them used Windows and were used to work with Java systems that required them to access a machine, replace a war file and execute some commands. In that opportunity, the solution was to create a deploy.sh file in the root folder on the application. This file was executed by somebody from the client every time they needed to update the application.

The problem mentioned above doesn’t happen with Inploy, as it can be run both remotely or locally. When running remotely, the only only thing it does is to connect to a list of servers and run the tasks like being locally logged. It’s because of this that Inploy is delivered as a plugin, so it’s available in all environments.

As today, Inploy will only work for you if you’re working with Git and Passenger.

To install Inploy you can execute:

script/plugin install git://github.com/dcrec1/inploy.git

On installation, Inploy will write to a file in config/deploy.rb. This file is read by the plugin and it should be something like this:

deploy.application = "inploy"
deploy.repository = 'git://github.com/dcrec1/inploy.git'
deploy.user = 'dcrec1'
deploy.hosts = ['hooters', 'geni']
deploy.path = '/var/local/apps'

After that, we’re ready to execute the tasks that the plugin has:

rake inploy:local:setup
rake inploy:local:update
rake inploy:remote:setup
rake inploy:remote:update

I created a short video in which I demonstrate how to use the different tasks of the plugin. In the video I’m inside the Signal project, which already has Inploy installed and I remove it along with the configuration file to demonstrate how easily it is to install and configure it. After that I execute a remote setup and then a remote update. We can see in the video that the commands that Inploy runs are logged with the corresponding outputs and that config/*.sample files are renamed to config/*, another feature of Inploy. In the second part of the video a local update is ran and then deleted the repository, cloned and executed another setup, this time locally.

Deploy easily to Locaweb with Inploy from Diego Carrion on Vimeo.

More details about the plugin can be obtained in the official Inploy repository, where I’ll try to keep the README up-to-date. I hope it’s clear the way that Inploy works, but just in case, looking at the code is an option to eliminate doubts. The code is quite small (50 LoC moreless) and also self explanatory. Follows an snippet:

def local_setup
  copy_sample_files
  create_folders 'tmp/pids', 'db'
  run "./init.sh" if File.exists?("init.sh")
  after_update_code
end
 
def remote_update
  remote_run "cd #{application_path} && rake inploy:local:update"
end
 
def local_update
  run "git pull origin master"
  after_update_code
end
 
def after_update_code
  install_gems
  migrate_database
  run "rm -R -f public/cache"
  rake_if_included "more:parse"
  rake_if_included "asset:packager:build_all"
  run "touch tmp/restart.txt"
end

I wish this simple code motivates people to contribute with the project and make it smarter.

If this plugins helps you, please consider to recommend me at Working With Rails.