From ac0f06a65fce93e86a153807900ee08897b594b6 Mon Sep 17 00:00:00 2001 From: Tim Smith Date: Tue, 7 Nov 2017 14:15:46 -0800 Subject: Detect new Amazon hypervisor used by the C5 instances Signed-off-by: Tim Smith --- lib/ohai/plugins/ec2.rb | 53 ++++++++++++++++++++++++++++++++++--------------- 1 file changed, 37 insertions(+), 16 deletions(-) diff --git a/lib/ohai/plugins/ec2.rb b/lib/ohai/plugins/ec2.rb index 1a3598d8..fdf0084a 100644 --- a/lib/ohai/plugins/ec2.rb +++ b/lib/ohai/plugins/ec2.rb @@ -21,7 +21,8 @@ # 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 Ohai.plugin(:EC2) do @@ -33,32 +34,43 @@ Ohai.plugin(:EC2) do include Ohai::Mixin::HttpHelper provides "ec2" - depends "dmi" - # look for amazon string in dmi bios data + # 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 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 # @return [Boolean] do we have Amazon DMI data? - def has_ec2_dmi? + 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") + 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") + Ohai::Log.debug("Plugin EC2: has_ec2_xen_dmi? == false") false end end - # looks for a xen UUID that starts with ec2 - # uses the sys tree on Linux and a WMI query on windows - # this gets us detection of 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") false @@ -82,13 +94,22 @@ Ohai.plugin(:EC2) do 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_ec2_identifying_number? + 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 -- cgit v1.2.1