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Viewing File: cron.rb
#
# Author:: Bryan McLellan (btm@loftninjas.org)
# Copyright:: Copyright 2009-2016, Bryan McLellan
# License:: Apache License, Version 2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
require "chef/log"
require "chef/mixin/command"
require "chef/provider"
class Chef
class Provider
class Cron < Chef::Provider
include Chef::Mixin::Command
provides :cron, os: ["!aix", "!solaris2"]
SPECIAL_TIME_VALUES = [:reboot, :yearly, :annually, :monthly, :weekly, :daily, :midnight, :hourly]
CRON_ATTRIBUTES = [:minute, :hour, :day, :month, :weekday, :time, :command, :mailto, :path, :shell, :home, :environment]
WEEKDAY_SYMBOLS = [:sunday, :monday, :tuesday, :wednesday, :thursday, :friday, :saturday]
CRON_PATTERN = /\A([-0-9*,\/]+)\s([-0-9*,\/]+)\s([-0-9*,\/]+)\s([-0-9*,\/]+|[a-zA-Z]{3})\s([-0-9*,\/]+|[a-zA-Z]{3})\s(.*)/
SPECIAL_PATTERN = /\A(@(#{SPECIAL_TIME_VALUES.join('|')}))\s(.*)/
ENV_PATTERN = /\A(\S+)=(\S*)/
def initialize(new_resource, run_context)
super(new_resource, run_context)
@cron_exists = false
@cron_empty = false
end
attr_accessor :cron_exists, :cron_empty
def whyrun_supported?
true
end
def load_current_resource
crontab_lines = []
@current_resource = Chef::Resource::Cron.new(new_resource.name)
current_resource.user(new_resource.user)
@cron_exists = false
if crontab = read_crontab
cron_found = false
crontab.each_line do |line|
case line.chomp
when "# Chef Name: #{new_resource.name}"
Chef::Log.debug("Found cron '#{new_resource.name}'")
cron_found = true
@cron_exists = true
next
when ENV_PATTERN
set_environment_var($1, $2) if cron_found
next
when SPECIAL_PATTERN
if cron_found
current_resource.time($2.to_sym)
current_resource.command($3)
cron_found = false
end
when CRON_PATTERN
if cron_found
current_resource.minute($1)
current_resource.hour($2)
current_resource.day($3)
current_resource.month($4)
current_resource.weekday($5)
current_resource.command($6)
cron_found = false
end
next
else
cron_found = false # We've got a Chef comment with no following crontab line
next
end
end
Chef::Log.debug("Cron '#{new_resource.name}' not found") unless @cron_exists
else
Chef::Log.debug("Cron empty for '#{new_resource.user}'")
@cron_empty = true
end
current_resource
end
def cron_different?
CRON_ATTRIBUTES.any? do |cron_var|
new_resource.send(cron_var) != current_resource.send(cron_var)
end
end
def action_create
crontab = String.new
newcron = String.new
cron_found = false
newcron = get_crontab_entry
if @cron_exists
unless cron_different?
Chef::Log.debug("Skipping existing cron entry '#{new_resource.name}'")
return
end
read_crontab.each_line do |line|
case line.chomp
when "# Chef Name: #{new_resource.name}"
cron_found = true
next
when ENV_PATTERN
crontab << line unless cron_found
next
when SPECIAL_PATTERN
if cron_found
cron_found = false
crontab << newcron
next
end
when CRON_PATTERN
if cron_found
cron_found = false
crontab << newcron
next
end
else
if cron_found # We've got a Chef comment with no following crontab line
crontab << newcron
cron_found = false
end
end
crontab << line
end
# Handle edge case where the Chef comment is the last line in the current crontab
crontab << newcron if cron_found
converge_by("update crontab entry for #{new_resource}") do
write_crontab crontab
Chef::Log.info("#{new_resource} updated crontab entry")
end
else
crontab = read_crontab unless @cron_empty
crontab << newcron
converge_by("add crontab entry for #{new_resource}") do
write_crontab crontab
Chef::Log.info("#{new_resource} added crontab entry")
end
end
end
def action_delete
if @cron_exists
crontab = String.new
cron_found = false
read_crontab.each_line do |line|
case line.chomp
when "# Chef Name: #{new_resource.name}"
cron_found = true
next
when ENV_PATTERN
next if cron_found
when SPECIAL_PATTERN
if cron_found
cron_found = false
next
end
when CRON_PATTERN
if cron_found
cron_found = false
next
end
else
# We've got a Chef comment with no following crontab line
cron_found = false
end
crontab << line
end
description = cron_found ? "remove #{new_resource.name} from crontab" : "save unmodified crontab"
converge_by(description) do
write_crontab crontab
Chef::Log.info("#{new_resource} deleted crontab entry")
end
end
end
private
def set_environment_var(attr_name, attr_value)
if %w{MAILTO PATH SHELL HOME}.include?(attr_name)
current_resource.send(attr_name.downcase.to_sym, attr_value.gsub(/^"|"$/, ""))
else
current_resource.environment(current_resource.environment.merge(attr_name => attr_value))
end
end
def read_crontab
crontab = nil
status = popen4("crontab -l -u #{new_resource.user}") do |pid, stdin, stdout, stderr|
crontab = stdout.read
end
if status.exitstatus > 1
raise Chef::Exceptions::Cron, "Error determining state of #{new_resource.name}, exit: #{status.exitstatus}"
end
crontab
end
def write_crontab(crontab)
write_exception = false
status = popen4("crontab -u #{new_resource.user} -", :waitlast => true) do |pid, stdin, stdout, stderr|
begin
stdin.write crontab
rescue Errno::EPIPE => e
# popen4 could yield while child has already died.
write_exception = true
Chef::Log.debug("#{e.message}")
end
end
if status.exitstatus > 0 || write_exception
raise Chef::Exceptions::Cron, "Error updating state of #{new_resource.name}, exit: #{status.exitstatus}"
end
end
def get_crontab_entry
newcron = ""
newcron << "# Chef Name: #{new_resource.name}\n"
[ :mailto, :path, :shell, :home ].each do |v|
newcron << "#{v.to_s.upcase}=\"#{new_resource.send(v)}\"\n" if new_resource.send(v)
end
new_resource.environment.each do |name, value|
newcron << "#{name}=#{value}\n"
end
if new_resource.time
newcron << "@#{new_resource.time} #{new_resource.command}\n"
else
newcron << "#{new_resource.minute} #{new_resource.hour} #{new_resource.day} #{new_resource.month} #{new_resource.weekday} #{new_resource.command}\n"
end
newcron
end
def weekday_in_crontab
weekday_in_crontab = WEEKDAY_SYMBOLS.index(new_resource.weekday)
if weekday_in_crontab.nil?
new_resource.weekday
else
weekday_in_crontab.to_s
end
end
end
end
end