Ruby Hooks
The hook execute option can also be provided Ruby code instead of a string. Here’s how it works:
- When the execute option is a String: Terraspace will shell out and run it as a script.
- When the execute option is a Ruby object: Terraspace will perform the
callmethod on the object or class.
Ruby Class
When the Ruby object is a class with an instance method call, Terraspace creates a new instance of the class and runs its call method. Example:
config/hooks/terraspace.rb
class EnvExporter
def call
ENV['SECRET_FOO'] = "bar"
end
end
before("build",
execute: EnvExporter,
)
Terraspace will do something like this:
EnvExporter.new.call
The example sets the SECRET_FOO environment variable. It is then available from ERB in the project files.
Ruby Object
When the Ruby object, Terraspace expects it to have a call method and will run it. Example:
config/hooks/terraspace.rb
before("compile",
execute: lambda { ENV['SECRET_FOO'] = "hi2" }
)
Terraspace will do something like this:
@hook[:execute].call
Process Context
The context in which the hook runs is worth highlighting. When the execute option is a String, Terraspace runs the script in a new child process. This the script is an independent process, and whatever is done to its environment is segregated.
When the execute option a Ruby object, then Terraspace runs the hook within the same process. It means the hook can affect the same environment. IE: Setting environment variables.
