Introducing rake tasks

From the previous error message, it's clear that first you need to have Rakefile. As you can see, there are four variants of its name: rakefile, Rakefile, rakefile.rb, and Rakefile.rb. The most popularly used variant is Rakefile. Rails also uses it. However, you can choose any variant for your project. There is no convention that prohibits the user from using any of the four suggested variants.

Rakefile is a file that is required for any Rake-based project. Apart from the fact that its content usually contains DSL, it's also a general Ruby file. Also, you can write any Ruby code in it. Perform the following steps to get started:

1. Let's create a Rakefile in the current folder, which will just say Hello Rake, using the following commands:

   $ echo "puts 'Hello Rake'" > Rakefile
   $ cat Rakefile
   puts 'Hello Rake'
   

   Here, the first line creates a Rakefile with the content, puts 'Hello Rake', and the second line just shows us its content to make sure that we've done everything correctly.

2. Now, run rake as we tried it before, using the following command:

   $ rake
   Hello Rake
   rake aborted!
   Don't know how to build task 'default'
   (See full trace by running task with --trace)
   

   The message has changed and it says Hello Rake. Then, it gets aborted because of another error message. At this moment, we have made the first step in learning Rake.

3. Now, we have to define a default rake task that will be executed when you try to start Rake without any arguments. To do so, open your editor and change the created Rakefile with the following content:

   task :default do
     puts 'Hello Rake'
   end

4. Now, run rake again:

   $ rake
   Hello, Rake
   

The output that says Hello, Rake demonstrates that the task works correctly.