Adding new crontab resource

The crontab resource parses a particular user's crontab file into
individual entries and allows the user to assert information about
each entry as needed.

Signed-off-by: Adam Leff <adam@leff.co>

docs/resources/crontab.md.erb

@@ -0,0 +1,62 @@
+---
+title: About the crontab Resource
+---
+
+# crontab
+
+Use the `crontab` InSpec audit resource to test the crontab entries for a particular user on the system.
+
+## Syntax
+
+A `crontab` resource block declares a user (which defaults to the current user, if not specified), and then the details to be tested, such as the schedule elements for each crontab entry or the commands itself:
+
+    describe crontab do
+      its('commands') { should include '/some/scheduled/task.sh' }
+    end
+
+## Matchers
+
+This InSpec audit resource has the following matchers:
+
+### be
+
+<%= partial "/shared/matcher_be" %>
+
+### cmp
+
+<%= partial "/shared/matcher_cmp" %>
+
+### eq
+
+<%= partial "/shared/matcher_eq" %>
+
+### include
+
+<%= partial "/shared/matcher_include" %>
+
+### match
+
+<%= partial "/shared/matcher_match" %>
+
+## Examples
+
+The following examples show how to use this InSpec audit resource.
+
+### Test that root's crontab has a particular command
+
+    describe crontab('root') do
+      its('commands') { should include '/path/to/some/script' }
+    end
+
+### Test that myuser's crontab entry for command '/home/myuser/build.sh' runs every minute
+
+    describe crontab('myuser').commands('/home/myuser/build.sh') do
+      its('hours') { should cmp '*' }
+      its('minutes') { should cmp '*' }
+    end
+
+### Test that the logged-in user's crontab has no tasks set to run on every hour and every minute
+
+    describe crontab.where({'hour' => '*', 'minute' => '*'}) do
+      its('entries.length') { should cmp '0' }
+    end

lib/inspec/resource.rb

@@ -79,6 +79,7 @@ require 'resources/bash'
 require 'resources/bond'
 require 'resources/bridge'
 require 'resources/command'
+require 'resources/crontab'
 require 'resources/directory'
 require 'resources/etc_group'
 require 'resources/file'

lib/resources/crontab.rb

@@ -0,0 +1,83 @@
+# encoding: utf-8
+# author: Adam Leff
+
+require 'utils/parser'
+require 'utils/filter'
+
+module Inspec::Resources
+  class Crontab < Inspec.resource(1)
+    name 'crontab'
+    desc 'Use the crontab InSpec audit resource to test the contents of the crontab for a given user which contains information about scheduled tasks owned by that user.'
+    example "
+      describe crontab('root') do
+        its('commands') { should include '/path/to/some/script' }
+      end
+
+      describe crontab('myuser').commands('/home/myuser/build.sh') do
+        its('hours') { should cmp '*' }
+        its('minutes') { should cmp '*' }
+      end
+
+      describe crontab.where({'hour' => '*', 'minute' => '*'}) do
+        its('entries.length') { should cmp '0' }
+      end
+    "
+
+    attr_reader :params
+
+    include CommentParser
+
+    def initialize(user = nil)
+      @user   = user
+      @params = read_crontab
+
+      return skip_resource 'The `crontab` resource is not supported on your OS.' unless inspec.os.unix?
+    end
+
+    def read_crontab
+      inspec.command(crontab_cmd).stdout.lines.map { |l| parse_crontab_line(l) }.compact
+    end
+
+    def parse_crontab_line(l)
+      data, = parse_comment_line(l, comment_char: '#', standalone_comments: false)
+      return nil if data.nil? || data.empty?
+
+      elements = data.split(/\s+/, 6)
+      {
+        'minute'  => elements.at(0),
+        'hour'    => elements.at(1),
+        'day'     => elements.at(2),
+        'month'   => elements.at(3),
+        'weekday' => elements.at(4),
+        'command' => elements.at(5),
+      }
+    end
+
+    def crontab_cmd
+      @user.nil? ? 'crontab -l' : "crontab -l -u #{@user}"
+    end
+
+    filter = FilterTable.create
+    filter.add_accessor(:where)
+          .add_accessor(:entries)
+          .add(:minutes,  field: 'minute')
+          .add(:hours,    field: 'hour')
+          .add(:days,     field: 'day')
+          .add(:months,   field: 'month')
+          .add(:weekdays, field: 'weekday')
+          .add(:commands, field: 'command')
+
+    # rebuild the crontab line from raw content
+    filter.add(:content) { |t, _|
+      t.entries.map do |e|
+        [e.minute, e.hour, e.day, e.month, e.weekday, e.command].join(' ')
+      end.join("\n")
+    }
+
+    filter.connect(self, :params)
+
+    def to_s
+      @user.nil? ? 'crontab for current user' : "crontab for user #{@user}"
+    end
+  end
+end

test/helper.rb

@@ -274,7 +274,11 @@ class MockLoader
       "schtasks /query /v /fo csv /tn 'does-not-exist' | ConvertFrom-Csv | Select @{N='URI';E={$_.TaskName}},@{N='State';E={$_.Status.ToString()}},'Logon Mode','Last Result','Task To Run','Run As User','Scheduled Task State' | ConvertTo-Json -Compress"  => cmd.call('schtasks-error'),
       # windows_task exist
       "schtasks /query /v /fo csv /tn 'WeLovePizza' | ConvertFrom-Csv | Select @{N='URI';E={$_.TaskName}},@{N='State';E={$_.Status.ToString()}},'Logon Mode','Last Result','Task To Run','Run As User','Scheduled Task State' | ConvertTo-Json -Compress"  => cmd.call('schtasks-success'),
-      'modinfo -F version dhcp' => cmd.call('modinfo-f-version-dhcp')
+      'modinfo -F version dhcp' => cmd.call('modinfo-f-version-dhcp'),
+      # crontab display for root / current user
+      'crontab -l' => cmd.call('crontab-root'),
+      # crontab display for non-current user
+      'crontab -l -u foouser' => cmd.call('crontab-foouser')
      }
 
     @backend

test/unit/mock/cmd/crontab-foouser

@@ -0,0 +1,5 @@
+#
+# This is a sample crontab file for unit testing, for user 'foouser'
+#
+
+* * * * * /path/to/script3

test/unit/mock/cmd/crontab-root

@@ -0,0 +1,10 @@
+#
+# This is a sample crontab file for unit testing
+#
+
+
+# entry number 1
+0 2 11 9 4 /path/to/script1
+
+# entry number 2
+1 3 12 10 5 /path/to/script2 arg1 arg2

test/unit/resources/crontab_test.rb

@@ -0,0 +1,78 @@
+# encoding: utf-8
+# author: Adam Leff
+
+require 'helper'
+require 'inspec/resource'
+
+describe 'Inspec::Resources::Crontab' do
+  let(:crontab) { load_resource('crontab') }
+
+  it 'retrieve minutes via field' do
+    _(crontab.minutes).must_equal [ '0', '1' ]
+  end
+
+  it 'retrieve hours via field' do
+    _(crontab.hours).must_equal [ '2', '3' ]
+  end
+
+  it 'retrieve days via field' do
+    _(crontab.days).must_equal [ '11', '12' ]
+  end
+
+  it 'retrieve months via field' do
+    _(crontab.months).must_equal [ '9', '10' ]
+  end
+
+  it 'retrieve weekdays via field' do
+    _(crontab.weekdays).must_equal [ '4', '5' ]
+  end
+
+  it 'retrieve commands via field' do
+    _(crontab.commands).must_equal [ '/path/to/script1', '/path/to/script2 arg1 arg2' ]
+  end
+
+  it 'returns all params of the file' do
+    _(crontab.params).must_equal([
+      {
+        'minute'  => '0',
+        'hour'    => '2',
+        'day'     => '11',
+        'month'   => '9',
+        'weekday' => '4',
+        'command' => '/path/to/script1',
+      },
+      {
+        'minute'  => '1',
+        'hour'    => '3',
+        'day'     => '12',
+        'month'   => '10',
+        'weekday' => '5',
+        'command' => '/path/to/script2 arg1 arg2'
+      },
+    ])
+  end
+
+  it 'prints a nice to_s string' do
+    _(crontab.to_s).must_equal "crontab for current user"
+  end
+
+  describe 'filter by command' do
+    let(:entry) { crontab.commands(/script2/) }
+
+    it 'returns the correct content' do
+      _(entry.content).must_equal '1 3 12 10 5 /path/to/script2 arg1 arg2'
+    end
+
+    it 'prints a nice to_s string' do
+      _(entry.to_s).must_equal 'crontab for current user with command == /script2/'
+    end
+  end
+
+  describe 'query by user' do
+    let(:crontab) { load_resource('crontab', 'foouser') }
+
+    it 'prints a user-specific to_s string' do
+      _(crontab.to_s).must_equal 'crontab for user foouser'
+    end
+  end
+end