Add version method to kernel_module

Signed-off-by: Andrey Aleksandrov <postgred@gmail.com>

docs/resources/kernel_module.md.erb

@@ -49,6 +49,12 @@ The `be_loaded` matcher tests if the module is a loadable kernel module:
 
 <%= partial "/shared/matcher_match" %>
 
+### version
+
+The `version` matcher tests if the named module version is on the system:
+
+    its(:version) { should eq '3.2.2' }
+
 ## Examples
 
 The following examples show how to use this InSpec audit resource.
@@ -57,4 +63,5 @@ The following examples show how to use this InSpec audit resource.
 
     describe kernel_module('bridge') do
       it { should be_loaded }
+      its(:version) { should cmp >= '2.2.2' }
     end

lib/resources/kernel_module.rb

@@ -36,6 +36,16 @@ module Inspec::Resources
       !found.nil?
     end
 
+    def version
+      # default modinfo command
+      modinfo_cmd = "modinfo -F version #{@module}"
+      # command for CentOS 5 and sudo
+      modinfo_cmd = "/sbin/modinfo -F version #{@module}" if inspec.os[:name] == 'centos' && inspec.os[:release].to_i == 5
+
+      cmd = inspec.command(modinfo_cmd)
+      cmd.exit_status.zero? ? cmd.stdout.gsub("\n", '') : false
+    end
+
     def to_s
       "Kernel Module #{@module}"
     end

test/helper.rb

@@ -269,6 +269,7 @@ 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')
      }
 
     @backend

test/unit/mock/cmd/modinfo-f-version-dhcp

@@ -0,0 +1 @@
+3.2.2

test/unit/resources/kernel_module_test.rb

@@ -20,4 +20,9 @@ describe 'Inspec::Resources::KernelModule' do
     resource = load_resource('kernel_module', 'dhcp')
     _(resource.loaded?).must_equal false
   end
+
+  it 'verify kernel_module version' do
+    resource = load_resource('kernel_module', 'dhcp')
+    _(resource.version).must_equal '3.2.2'
+  end
 end