Merge pull request #1111 from chef/fix_ec2

Backport support for new EC2 instance types

2 files changed, 124 insertions, 43 deletions

diff --git a/lib/ohai/plugins/ec2.rb b/lib/ohai/plugins/ec2.rb
index 4d647fb2..454642d4 100644
--- a/lib/ohai/plugins/ec2.rb
+++ b/lib/ohai/plugins/ec2.rb
@@ -21,65 +21,94 @@
 # How we detect EC2 from easiest to hardest & least reliable
 # 1. Ohai ec2 hint exists. This always works
 # 2. Xen hypervisor UUID starts with 'ec2'. This catches Linux HVM & paravirt instances
-# 3. DMI data mentions amazon. This catches HVM instances in a VPC
+# 3. DMI bios version data mentions amazon. This catches HVM instances in a VPC on the Xen based hypervisor
+# 3. DMI bios vendor data mentions amazon. This catches HVM instances in a VPC on the non-Xen based hypervisor
 # 4. Kernel data mentioned Amazon. This catches Windows HVM & paravirt instances
 
-require "ohai/mixin/ec2_metadata"
-require "base64"
-
 Ohai.plugin(:EC2) do
+  require "ohai/mixin/ec2_metadata"
+  require "base64"
+
   include Ohai::Mixin::Ec2Metadata
 
   provides "ec2"
 
-  depends "dmi"
-  depends "kernel"
+  # look for amazon string in dmi vendor bios data within the sys tree.
+  # this works even if the system lacks dmidecode use by the Dmi plugin
+  # this gets us detection of new Xen-less HVM instances that are within a VPC
+  # @return [Boolean] do we have Amazon DMI data?
+  def has_ec2_amazon_dmi?
+    # detect a version of '4.2.amazon'
+    if file_val_if_exists("/sys/class/dmi/id/bios_vendor") =~ /Amazon/
+      Ohai::Log.debug("Plugin EC2: has_ec2_amazon_dmi? == true")
+      true
+    else
+      Ohai::Log.debug("Plugin EC2: has_ec2_amazon_dmi? == false")
+      false
+    end
+  end
 
-  # look for amazon string in dmi bios data
+  # look for amazon string in dmi bios version data within the sys tree.
+  # this works even if the system lacks dmidecode use by the Dmi plugin
   # this gets us detection of HVM instances that are within a VPC
-  def has_ec2_dmi?
+  # @return [Boolean] do we have Amazon DMI data?
+  def has_ec2_xen_dmi?
     # detect a version of '4.2.amazon'
-    if get_attribute(:dmi, :bios, :all_records, 0, :Version) =~ /amazon/
-      Ohai::Log.debug("Plugin EC2: has_ec2_dmi? == true")
-      return true
+    if file_val_if_exists("/sys/class/dmi/id/bios_version") =~ /amazon/
+      Ohai::Log.debug("Plugin EC2: has_ec2_xen_dmi? == true")
+      true
     else
-      Ohai::Log.debug("Plugin EC2: has_ec2_dmi? == false")
-      return false
+      Ohai::Log.debug("Plugin EC2: has_ec2_xen_dmi? == false")
+      false
     end
   end
 
-  # looks for a xen UUID that starts with ec2
-  # this gets us detection of Linux HVM and Paravirt hosts
+  # looks for a xen UUID that starts with ec2 from within the Linux sys tree
+  # @return [Boolean] do we have a Xen UUID or not?
   def has_ec2_xen_uuid?
-    if ::File.exist?("/sys/hypervisor/uuid")
-      if ::File.read("/sys/hypervisor/uuid") =~ /^ec2/
-        Ohai::Log.debug("Plugin EC2: has_ec2_xen_uuid? == true")
-        return true
-      end
+    if file_val_if_exists("/sys/hypervisor/uuid") =~ /^ec2/
+      Ohai::Log.debug("Plugin EC2: has_ec2_xen_uuid? == true")
+      return true
     end
     Ohai::Log.debug("Plugin EC2: has_ec2_xen_uuid? == false")
-    return false
+    false
   end
 
-  # looks for the Amazon.com Organization in Windows Kernel data
-  # this gets us detection of Windows systems
-  def has_amazon_org?
-    # detect an Organization of 'Amazon.com'
-    if get_attribute(:kernel, :os_info, :organization) =~ /Amazon/
-      Ohai::Log.debug("Plugin EC2: has_amazon_org? == true")
-      return true
+  # looks at the identifying number WMI value to see if it starts with ec2.
+  # this is actually the same value we're looking at in has_ec2_xen_uuid? on
+  # linux hosts
+  # @return [Boolean] do we have a Xen Identifying Number or not?
+  def has_ec2_identifying_number?
+    if RUBY_PLATFORM =~ /mswin|mingw32|windows/
+      require "wmi-lite/wmi"
+      wmi = WmiLite::Wmi.new
+      if wmi.first_of("Win32_ComputerSystemProduct")["identifyingnumber"] =~ /^ec2/
+        Ohai::Log.debug("Plugin EC2: has_ec2_identifying_number? == true")
+        return true
+      end
     else
-      Ohai::Log.debug("Plugin EC2: has_amazon_org? == false")
-      return false
+      Ohai::Log.debug("Plugin EC2: has_ec2_identifying_number? == false")
+      false
+    end
+  end
+
+  # return the contents of a file if the file exists
+  # @param path[String] abs path to the file
+  # @return [String] contents of the file if it exists
+  def file_val_if_exists(path)
+    if ::File.exist?(path)
+      ::File.read(path)
     end
   end
 
+  # a single check that combines all the various detection methods for EC2
+  # @return [Boolean] Does the system appear to be on EC2
   def looks_like_ec2?
     return true if hint?("ec2")
 
     # Even if it looks like EC2 try to connect first
-    if has_ec2_xen_uuid? || has_ec2_dmi? || has_amazon_org?
-      return true if can_metadata_connect?(Ohai::Mixin::Ec2Metadata::EC2_METADATA_ADDR, 80)
+    if has_ec2_xen_uuid? || has_ec2_amazon_dmi? || has_ec2_xen_dmi? || has_ec2_identifying_number?
+      return true if can_socket_connect?(Ohai::Mixin::Ec2Metadata::EC2_METADATA_ADDR, 80)
     end
   end
 
diff --git a/spec/unit/plugins/ec2_spec.rb b/spec/unit/plugins/ec2_spec.rb
index ef35cee8..f9c62150 100644
--- a/spec/unit/plugins/ec2_spec.rb
+++ b/spec/unit/plugins/ec2_spec.rb
@@ -17,20 +17,22 @@
 # limitations under the License.
 #
 
-require File.expand_path(File.dirname(__FILE__) + "/../../spec_helper.rb")
+require_relative "../../spec_helper.rb"
 require "open-uri"
 require "base64"
 
 describe Ohai::System, "plugin ec2" do
 
+  let(:plugin) { get_plugin("ec2") }
+
   before(:each) do
     allow(plugin).to receive(:hint?).with("ec2").and_return(false)
     allow(File).to receive(:exist?).with("/sys/hypervisor/uuid").and_return(false)
+    allow(File).to receive(:exist?).with("/sys/class/dmi/id/bios_vendor").and_return(false)
+    allow(File).to receive(:exist?).with("/sys/class/dmi/id/bios_version").and_return(false)
   end
 
   shared_examples_for "!ec2" do
-    let(:plugin) { get_plugin("ec2") }
-
     it "DOESN'T attempt to fetch the ec2 metadata or set ec2 attribute" do
       expect(plugin).not_to receive(:http_client)
       expect(plugin[:ec2]).to be_nil
@@ -39,8 +41,6 @@ describe Ohai::System, "plugin ec2" do
   end
 
   shared_examples_for "ec2" do
-    let(:plugin) { get_plugin("ec2") }
-
     before(:each) do
       @http_client = double("Net::HTTP client")
       allow(plugin).to receive(:http_client).and_return(@http_client)
@@ -334,19 +334,39 @@ describe Ohai::System, "plugin ec2" do
     end
   end # shared examples for ec2
 
-  describe "with ec2 dmi data" do
+  describe "with amazon dmi bios version data" do
     it_behaves_like "ec2"
 
     before(:each) do
-      plugin[:dmi] = { :bios => { :all_records => [ { :Version => "4.2.amazon" } ] } }
+      allow(File).to receive(:exist?).with("/sys/class/dmi/id/bios_version").and_return(true)
+      allow(File).to receive(:read).with("/sys/class/dmi/id/bios_version").and_return("4.2.amazon\n")
     end
   end
 
-  describe "with amazon kernel data" do
+  describe "with non-amazon dmi bios version data" do
+    it_behaves_like "!ec2"
+
+    before(:each) do
+      allow(File).to receive(:exist?).with("/sys/class/dmi/id/bios_version").and_return(true)
+      allow(File).to receive(:read).with("/sys/class/dmi/id/bios_version").and_return("1.0\n")
+    end
+  end
+
+  describe "with amazon dmi bios vendor data" do
     it_behaves_like "ec2"
 
     before(:each) do
-      plugin[:kernel] = { :os_info => { :organization => "Amazon.com" } }
+      allow(File).to receive(:exist?).with("/sys/class/dmi/id/bios_vendor").and_return(true)
+      allow(File).to receive(:read).with("/sys/class/dmi/id/bios_vendor").and_return("Amazon EC2\n")
+    end
+  end
+
+  describe "with non-amazon dmi bios vendor data" do
+    it_behaves_like "!ec2"
+
+    before(:each) do
+      allow(File).to receive(:exist?).with("/sys/class/dmi/id/bios_vendor").and_return(true)
+      allow(File).to receive(:read).with("/sys/class/dmi/id/bios_vendor").and_return("Xen\n")
     end
   end
 
@@ -355,7 +375,7 @@ describe Ohai::System, "plugin ec2" do
 
     before(:each) do
       allow(File).to receive(:exist?).with("/sys/hypervisor/uuid").and_return(true)
-      allow(File).to receive(:read).with("/sys/hypervisor/uuid").and_return("ec2a0561-e4d6-8e15-d9c8-2e0e03adcde8")
+      allow(File).to receive(:read).with("/sys/hypervisor/uuid").and_return("ec2a0561-e4d6-8e15-d9c8-2e0e03adcde8\n")
     end
   end
 
@@ -364,7 +384,39 @@ describe Ohai::System, "plugin ec2" do
 
     before(:each) do
       allow(File).to receive(:exist?).with("/sys/hypervisor/uuid").and_return(true)
-      allow(File).to receive(:read).with("/sys/hypervisor/uuid").and_return("123a0561-e4d6-8e15-d9c8-2e0e03adcde8")
+      allow(File).to receive(:read).with("/sys/hypervisor/uuid").and_return("123a0561-e4d6-8e15-d9c8-2e0e03adcde8\n")
+    end
+  end
+
+  describe "with EC2 Identifying Number", :windows_only do
+    it_behaves_like "ec2"
+
+    before do
+      allow_any_instance_of(WmiLite::Wmi).to receive(:first_of).and_return(
+        { "caption" => "Computer System Product",
+          "description" => "Computer System Product",
+          "identifyingnumber" => "ec2a355a-91cd-5fe8-bbfc-cc891d0bf9d6",
+          "name" => "HVM domU",
+          "skunumber" => nil,
+          "uuid" => "5A352AEC-CD91-E85F-BBFC-CC891D0BF9D6",
+          "vendor" => "Xen",
+          "version" => "4.2.amazon" })
+    end
+  end
+
+  describe "without EC2 Identifying Number", :windows_only do
+    it_behaves_like "!ec2"
+
+    before do
+      allow_any_instance_of(WmiLite::Wmi).to receive(:first_of).and_return(
+        { "caption" => "Computer System Product",
+          "description" => "Computer System Product",
+          "identifyingnumber" => "1234",
+          "name" => "HVM domU",
+          "skunumber" => nil,
+          "uuid" => "5A352AEC-CD91-E85F-BBFC-CC891D0BF9D6",
+          "vendor" => "Xen",
+          "version" => "1.2.3" })
     end
   end