Dump Amazon EC2 metadata server's params.

dump-metadata.sh

#!/bin/bash
#
# $ ./dump-metadata.sh [ PARAM ]...
#
# $ ./dump-metadata.sh
# $ ./dump-metadata.sh /
# $ ./dump-metadata.sh /ami-id
# $ ./dump-metadata.sh /public-ipv4
# $ ./dump-metadata.sh /ami-id /public-ipv4
#
LANG=C
LC_ALL=C

set -e

api_base_uri=http://169.254.169.254/latest/meta-data

function retrieve_meta_data() {
  curl -s -f --retry 3 ${api_base_uri}$1
}

function meta_data() {
  local param=$1

  case ${param} in
  */)
    for i in $(retrieve_meta_data ${param}); do
      meta_data ${param}${i}
    done
    ;;
  *=*)
    echo "${param} = "
    meta_data ${param%%=*}/
    ;;
  *)
    echo -n "${param} = "
    echo $(retrieve_meta_data ${param})
    ;;
  esac
}

if [ $# = 0 ]; then
  meta_data /
else
  while [ $# -gt 0 ]; do
    #meta_data /
    meta_data $1
    shift
  done
fi