Class: Sunshine::Crontab

Inherits:
Object
  • Object
show all
Defined in:
lib/sunshine/crontab.rb

Overview

A simple namespaced grouping of cron jobs that can be read and written to a shell.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, shell) ⇒ Crontab

Returns a new instance of Crontab.



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# File 'lib/sunshine/crontab.rb', line 11

def initialize name, shell
  @name  = name
  @shell = shell
  @jobs  = nil
end

Instance Attribute Details

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/sunshine/crontab.rb', line 9

def name
  @name
end

#shell ⇒ Object (readonly)

Returns the value of attribute shell.



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# File 'lib/sunshine/crontab.rb', line 9

def shell
  @shell
end

Instance Method Details

#[](key) ⇒ Object

Access the jobs hash. Equivalent to:

crontab.jobs[key]



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# File 'lib/sunshine/crontab.rb', line 22

def [] key
  self.jobs[key]
end

#[]=(key, value) ⇒ Object

Set a value in the jobs hash.Equivalent to:

crontab.jobs[key] = value



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# File 'lib/sunshine/crontab.rb', line 31

def []= key, value
  self.jobs[key] = value
end

#build(crontab = "") ⇒ Object

Build the crontab by replacing preexisting cron jobs and adding new ones.



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# File 'lib/sunshine/crontab.rb', line 48

def build crontab=""
  crontab.strip!

  jobs.each do |namespace, cron_job|
    cron_job = cron_job.join("\n") if Array === cron_job
    crontab  = delete_jobs crontab, namespace

    next if cron_job.nil? || cron_job.empty?

    start_id, end_id = get_job_ids namespace
    cron_str = "\n#{start_id}\n#{cron_job.chomp}\n#{end_id}\n\n"

    crontab << cron_str
  end

  crontab
end

#delete! ⇒ Object

Remove all cron jobs that reference crontab.name.



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# File 'lib/sunshine/crontab.rb', line 70

def delete!
  crontab = read_crontab
  crontab = delete_jobs crontab

  write_crontab crontab

  crontab
end

#jobs ⇒ Object

Get the jobs matching this crontab. Loads them from the crontab if @jobs hasn’t been set yet.



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# File 'lib/sunshine/crontab.rb', line 40

def jobs
  @jobs ||= parse read_crontab
end

#modified? ⇒ Boolean

Checks if the crontab was modified for crontab.name.

Returns:

  • (Boolean) 


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# File 'lib/sunshine/crontab.rb', line 99

def modified?
  !@jobs.nil?
end

#parse(string) ⇒ Object

Load a crontab string and parse out jobs related to crontab.name. Returns a hash of namespace/jobs pairs.



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# File 'lib/sunshine/crontab.rb', line 108

def parse string
  jobs = Hash.new{|hash, key| hash[key] = Array.new}

  namespace = nil

  string.each_line do |line|
    if line =~ /^# sunshine #{@name}:(.*):begin/
      namespace = $1
      next
    elsif line =~ /^# sunshine #{@name}:#{namespace}:end/
      namespace = nil
    end

    if namespace
      line = line.strip
      jobs[namespace] << line unless line.empty?
    end
  end

  jobs unless jobs.empty?
end

#read_crontab ⇒ Object

Returns the shell’s crontab as a string



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# File 'lib/sunshine/crontab.rb', line 134

def read_crontab
  @shell.call("crontab -l") rescue ""
end

#write! ⇒ Object

Write the crontab on the given shell



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# File 'lib/sunshine/crontab.rb', line 83

def write!
  return unless modified?

  crontab = read_crontab
  crontab = delete_jobs crontab
  crontab = build crontab

  write_crontab crontab

  crontab
end