wmi unit test

lib/resources/wmi.rb

@@ -5,6 +5,10 @@
 require 'utils/object_traversal'
 
 module Inspec::Resources
+  # This resource simplifies the access to wmi
+  # on CLI you would use:
+  # WMIC /NAMESPACE:\\root\rsop\computer PATH RSOP_SecuritySettingNumeric WHERE "KeyName = 'MinimumPasswordAge' And precedence=1" GET Setting
+  # We use Get-WmiObject via Powershell to retrieve all values.
   class WMI < Inspec.resource(1)
     name 'wmi'
     desc 'request wmi information'
@@ -18,24 +22,26 @@ module Inspec::Resources
     "
 
     include ObjectTraverser
-
-    # This would be the same as:
-    # WMIC /NAMESPACE:\\root\rsop\computer PATH RSOP_SecuritySettingNumeric WHERE "KeyName = 'MinimumPasswordAge' And precedence=1" GET Setting
     attr_accessor :content
+
     def initialize(wmiclass, opts = {})
+      # verify that this resource is only supported on Windows
+      return skip_resource 'The `windows_feature` resource is not supported on your OS.' unless inspec.os.windows?
+
       @wmiclass = wmiclass
       @wminamespace = opts[:namespace]
       @wmifilter = opts[:filter]
-
-      # verify that this resource is only supported on Windows
-      return skip_resource 'The `windows_feature` resource is not supported on your OS.' unless inspec.os.windows?
     end
 
     # returns nil, if not existant or value
     def method_missing(*keys)
-      # catch bahavior of rspec its implementation
+      # catch behavior of rspec its implementation
       # @see https://github.com/rspec/rspec-its/blob/master/lib/rspec/its.rb#L110
       keys.shift if keys.is_a?(Array) && keys[0] == :[]
+
+      # map all symbols to strings
+      keys = keys.map(&:to_s) if keys.is_a?(Array)
+
       value(keys)
     end
 
@@ -47,6 +53,10 @@ module Inspec::Resources
       return @content if defined?(@content)
       @content = {}
 
+      # we should abort execution, if wmi class is not given or wmi resource is
+      # executed on a non-windows system
+      return @content if @wmiclass.nil?
+
       # optional params
       cmd_namespace = "-namespace #{@wminamespace}" unless @wminamespace.nil?
       cmd_filter = "-filter \"#{@wmifilter}\"" unless @wmifilter.nil?
@@ -54,7 +64,7 @@ module Inspec::Resources
       # run wmi command
       cmd = inspec.command("Get-WmiObject -class #{@wmiclass} #{cmd_namespace} #{cmd_filter} | ConvertTo-Json")
       @content = JSON.parse(cmd.stdout)
-    rescue JSON::ParserError => e
+    rescue JSON::ParserError => _e
       @content
     end
 

lib/utils/object_traversal.rb

@@ -4,7 +4,7 @@
 module ObjectTraverser
   def extract_value(keys, value)
     key = keys.shift
-    return nil if key.nil?
+    return nil if key.nil? || value.nil?
 
     # if value is an array, iterate over each child
     if value.is_a?(Array)

test/helper.rb

@@ -237,6 +237,8 @@ class MockLoader
       'netstat -an -f inet -f inet6' => cmd.call('s11-netstat-an-finet-finet6'),
       # xinetd configuration
       'find /etc/xinetd.d -type f' => cmd.call('find-xinetd.d'),
+      # wmi test
+      "Get-WmiObject -class win32_service  -filter \"name like '%winrm%'\" | ConvertTo-Json" => cmd.call('get-wmiobject'),
     }
 
     @backend

test/unit/mock/cmd/get-wmiobject

@@ -0,0 +1,10 @@
+{
+    "Path":  {
+                 "ClassName":  "Win32_Service"
+             },
+    "Caption":  "Windows Remote Management (WS-Management)",
+    "CreationClassName":  "Win32_Service",
+    "DisplayName":  "Windows Remote Management (WS-Management)",
+    "Name":  "WinRM",
+    "PathName":  "C:\\Windows\\System32\\svchost.exe -k NetworkService"
+}

test/unit/resources/wmi_test.rb

@@ -0,0 +1,45 @@
+# encoding: utf-8
+# author: Christoph Hartmann
+# author: Dominik Richter
+
+require 'helper'
+require 'inspec/resource'
+
+describe 'Inspec::Resources::WMI' do
+
+  # Check the following as unit test
+  # describe wmi('win32_service', {
+  #   filter: "name like '%winrm%'"
+  # }) do
+  #   its(['Path','ClassName']) { should eq 'Win32_Service' }
+  #   its('DisplayName') { should eq 'Windows Remote Management (WS-Management)'}
+  # end
+
+  # windows
+  it 'verify wmi parsing on windows' do
+    resource = MockLoader.new(:windows).load_resource('wmi', 'win32_service', { filter: "name like '%winrm%'" })
+    _(resource.send('DisplayName')).must_equal 'Windows Remote Management (WS-Management)'
+    _(resource.send('method_missing', 'Path', 'ClassName')).must_equal 'Win32_Service'
+  end
+
+  # ubuntu 14.04 with upstart
+  it 'fail wmi on ubuntu' do
+    resource = MockLoader.new(:ubuntu1404).load_resource('wmi', 'win32_service', { filter: "name like '%winrm%'" })
+    _(resource.send('DisplayName')).must_equal nil
+    _(resource.send('method_missing', 'Path', 'ClassName')).must_equal nil
+  end
+
+  # centos 7 with systemd
+  it 'fail wmi on centos' do
+    resource = MockLoader.new(:centos7).load_resource('wmi', 'win32_service', { filter: "name like '%winrm%'" })
+    _(resource.send('DisplayName')).must_equal nil
+    _(resource.send('method_missing', 'Path', 'ClassName')).must_equal nil
+  end
+
+  # unknown OS
+  it 'fail wmi on unknown os' do
+    resource = MockLoader.new(:undefined).load_resource('wmi', 'win32_service', { filter: "name like '%winrm%'" })
+    _(resource.send('DisplayName')).must_equal nil
+    _(resource.send('method_missing', 'Path', 'ClassName')).must_equal nil
+  end
+end