Puppet » Facter

When a xen dom0 is setup in bridging mode the xen scripts will create a bridge and a bunch of virtual interfaces all with the MAC address FE:FF:FF:FF:FF:FF, this results in domU with the arp fact set to this which triggers the ec2 facts incorrectly.

% facter arp
fe:ff:ff:ff:ff:ff

From the ec2.rb:

def can_connect?(wait_sec=2)
  url = "http://169.254.169.254:80/"
  Timeout::timeout(wait_sec) {open(url)}
  return true
  rescue Timeout::Error
    return false
  rescue
    return false
end

def has_ec2_arp?
   !!(Facter.value(:arp) == "fe:ff:ff:ff:ff:ff")
end

if (has_euca_mac? || has_ec2_arp?) && can_connect?
   .
   .
   .

So since on this specific setup the has_ec2_arp? method returns true the can_connect? method gets run which has a 2 second timeout and it will fail to connect. This fact runs twice resulting in a 4 second slow down.

This is on CentOS 5.6