writing_your_own_tasks.md

Writing your own tasks

Defining tasks

The file deploy.rb is simply a Rakefile invoked by Rake. In fact, mina is mostly an alias that invokes Rake to load deploy.rb.

## Sample config/deploy.rb
set :domain, 'your.server.com'

task :restart do
  comment 'Restart application'
  command "passenger-config restart-app --ignore-app-not-running #{deploy_to}"
end

As it's all Rake, you can define tasks that you can invoke using mina. In this example, it provides the mina restart command.

The magic of Mina is in the new commands it gives you.

The command command queues up Bash commands to be run on the remote server. If you invoke mina restart, it will invoke the task above and run the queued commands on the remote server your.server.com via SSH.

DSL

Helpers

invoke

Invokes another Rake task.

invoke :'git:clone'
invoke :restart

command

Adds a command to the command queue.

This queues code to be run on the current queue name (defaults to :default).

By default, whitespace is stripped from the beginning and end of the command.

command %{ls -al} # => [ls -al]

comment

Adds a comment to the command queue.

comment %{ls -al} # => [echo "-----> ls -al"]

run

Runs the given block on the defined backend (remote or local)

run :remote do
  command %{ls -al}
end

on

Change the queue name for the given block. Use this if you have multiple places where commands need to end up. Mainly used in deploy task.

on :launch do
  invoke :restart
end

in_path

Change the path the commands in the given block is run.

in_path('some/new/path') do
  command %{ls -al} # => cd some/new/path && ls -al
end

Configuration

set

Sets configuration variable. Can a value or a proc/lambda.

set :deploy_to -> '/path/to/deploy'

fetch

Gets configuration variable. Runs .call if callable. Returns nil if not set. If default parameter is passed returns default if not set.

fetch(:deploy_to)
fetch(:deploy_to, 'some_default')

set?

Checks if a variable is set.

set?(:deploy_to)

ensure!

Raises an error if variable is not set

ensure!(:deploy_to)