src/initscripts/system/aws

   1 #!/bin/sh
   2 ########################################################################
   3 # Begin $rc_base/init.d/aws
   4 ########################################################################
   5
   6 . /etc/sysconfig/rc
   7 . ${rc_functions}
   8
   9 # https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/identify_ec2_instances.html
  10 running_on_ec2() {
  11         local uuid
  12
  13         # Check if the hypervisor UUID starts with ec2
  14         if [ -r "/sys/hypervisor/uuid" ]; then
  15                 uuid=$(</sys/hypervisor/uuid)
  16
  17                 [ "${uuid:0:3}" = "ec2" ] && return 0
  18         fi
  19
  20         # Check if the DMI product UUID starts with EC2
  21         if [ -r "/sys/devices/virtual/dmi/id/product_uuid" ]; then
  22                 uuid=$(</sys/devices/virtual/dmi/id/product_uuid)
  23
  24                 [ "${uuid:0:3}" = "EC2" ] && return 0
  25         fi
  26
  27         # We are not running on AWS EC2
  28         return 1
  29 }
  30
  31 case "${1}" in
  32         start)
  33                 # Do nothing if we are not running on AWS EC2
  34                 running_on_ec2 || exit 0
  35
  36                 # Find the first interface to use
  37                 for i in /sys/class/net/*; do
  38                         [ -d "${i}" ] || continue
  39                         i=$(basename ${i})
  40
  41                         # Skip loopback
  42                         [ "${i}" = "lo" ] && continue
  43
  44                         # Use whatever we have found
  45                         intf="${i}"
  46                         break
  47                 done
  48
  49                 # Check if we found a network interface
  50                 if [ ! -n "${intf}" ]; then
  51                         echo_failure
  52
  53                         boot_mesg -n "Could not find a network interface" ${FAILURE}
  54                         boot_mesg "" ${NORMAL}
  55                 fi
  56
  57                 # Run a DHCP client and set up the system accordingly
  58                 dhclient -sf /etc/rc.d/helper/aws-setup "${intf}"
  59
  60                 # End DHCP client immediately
  61                 dhclient -sf /etc/rc.d/helper/aws-setup -r "${intf}" &>/dev/null
  62
  63                 exit 0
  64                 ;;
  65
  66         status)
  67                 if running_on_ec2; then
  68                         echo "This system is running on AWS EC2"
  69                         exit 0
  70                 else
  71                         echo "This system is NOT running on AWS EC2"
  72                         exit 1
  73                 fi
  74                 ;;
  75
  76         *)
  77                 echo "Usage: ${0} {start|status}"
  78                 exit 1
  79                 ;;
  80 esac
  81
  82 # End $rc_base/init.d/aws