if iam returns no users at all, it is likey down (implementation merged from https://github.com/packetfairy/aws-ec2-ssh/blob/condoms/import_users.sh#L285) fixes #96

Author: michaelwittig

import_users.sh

@@ -250,7 +250,17 @@ function sync_accounts() {
     get_sudoers_groups_from_tag
 
     iam_users=$(get_clean_iam_users | sort | uniq)
+    if [ -z "${iam_users}" ]; then
+      logger 'we just got back an empty iam_users user list -- that sounds wrong; bailing out!'
+      exit 1
+    fi
+
     sudo_users=$(get_clean_sudoers_users | sort | uniq)
+    if [ -z "${sudo_users}" ]; then
+      logger 'we just got back an empty sudo_users user list -- that sounds wrong; bailing out!'
+      exit 1
+    fi
+
     local_users=$(get_local_users | sort | uniq)
 
     intersection=$(echo ${local_users} ${iam_users} | tr " " "\n" | sort | uniq -D | uniq)