Merge pull request #828 from chef/gentoo

Switch to kernel version to identify Gentoo versions

lib/ohai/plugins/linux/platform.rb

@@ -118,7 +118,10 @@ def os_release_file_is_cisco?
       platform_version get_redhatish_version(contents)
     elsif File.exist?("/etc/gentoo-release")
       platform "gentoo"
-      platform_version File.read("/etc/gentoo-release").scan(/(\d+|\.+)/).join
+      # the gentoo release version is the base version used to bootstrap
+      # a node and doesn't have a lot of meaning in a rolling release distro
+      # kernel release will be used - ex. 3.18.7-gentoo
+      platform_version `uname -r`.strip
     elsif File.exist?("/etc/SuSE-release")
       suse_release = File.read("/etc/SuSE-release")
       suse_version = suse_release.scan(/VERSION = (\d+)\nPATCHLEVEL = (\d+)/).flatten.join(".")

spec/unit/plugins/linux/platform_spec.rb

@@ -217,11 +217,16 @@
     end
 
     it "should set platform and platform_family to gentoo" do
-      expect(File).to receive(:read).with("/etc/gentoo-release").and_return("Gentoo Base System release 1.20.1.1")
       @plugin.run
       expect(@plugin[:platform]).to eq("gentoo")
       expect(@plugin[:platform_family]).to eq("gentoo")
     end
+
+    it "should set platform_version to kernel release" do
+      expect(@plugin).to receive(:`).with("uname -r").and_return("3.18.7-gentoo")
+      @plugin.run
+      expect(@plugin[:platform_version]).to eq("3.18.7-gentoo")
+    end
   end
 
   describe "on alpine" do