Merged change 14c58f92-44e3-42c0-8737-71c6b49d0e42

From review branch _reviews/master/improve-pip-windows/2 into master

Signed-off-by: drichter <drichter@chef.io>

lib/resources/pip.rb

@@ -4,6 +4,7 @@
 # describe pip('Jinja2') do
 #   it { should be_installed }
 # end
+#
 class PipPackage < Vulcano.resource(1)
   name 'pip'
 
@@ -16,8 +17,7 @@ class PipPackage < Vulcano.resource(1)
 
     @info = {}
     @info[:type] = 'pip'
-
-    cmd = vulcano.run_command("pip show #{@package_name}")
+    cmd = vulcano.run_command("#{pip_cmd} show #{@package_name}")
     return @info if cmd.exit_status != 0
 
     params = SimpleConfig.new(
@@ -42,4 +42,32 @@ class PipPackage < Vulcano.resource(1)
   def to_s
     "pip package  #{@package_name}"
   end
+
+  private
+
+  def pip_cmd
+    # Pip is not on the default path for Windows, therefore we do some logic
+    # to find the binary on Windows
+    family = vulcano.os[:family]
+    case family
+    when 'windows'
+      # we need to detect the pip command on Windows
+      cmd = vulcano.run_command('New-Object -Type PSObject | Add-Member -MemberType NoteProperty -Name Pip -Value (Invoke-Command -ScriptBlock {where.exe pip}) -PassThru | Add-Member -MemberType NoteProperty -Name Python -Value (Invoke-Command -ScriptBlock {where.exe python}) -PassThru | ConvertTo-Json')
+      begin
+        paths = JSON.parse(cmd.stdout)
+        # use pip if it on system path
+        pipcmd = paths['Pip']
+        # calculate path on windows
+        if defined?(paths['Python']) && pipcmd.nil?
+          pipdir = paths['Python'].split('\\')
+          # remove python.exe
+          pipdir.pop
+          pipcmd = pipdir.push('Scripts').push('pip.exe').join('/')
+        end
+      rescue JSON::ParserError => _e
+        return nil
+      end
+    end
+    pipcmd || 'pip'
+  end
 end