Showing posts with label meta. Show all posts
Showing posts with label meta. Show all posts

Wednesday, May 15, 2013

EC2 (classic) instance hostname is not hostname and is not hostname


This is the results from wget and hostname at command line.
1. wget -q -O - http://169.254.169.254/latest/meta-data/public-hostname
Output ---> ec2-50-13-20-1.compute-1.amazonaws.com
2. wget -q -O - http://169.254.169.254/latest/meta-data/hostname
Output-->   ip-10-222-1-241.ec2.internal
3. wget -q -O - http://169.254.169.254/latest/meta-data/local-hostname
output--->ip-10-222-1-241.ec2.internal
4. wget -q -O - http://169.254.169.254/latest/meta-data/local-ipv4
output--->10.222.1.241
5. wget -q -O - http://169.254.169.254/latest/meta-data/public-ipv4
50.13.20.1
6. [root@wls1 ~]# hostname  ---> linux command line
wls1.labs.oracleweblogic.com

Someone changed the host name after boot or at boot time using user-data or another method.  Normally you would see:


1. wget -q -O - http://169.254.169.254/latest/meta-data/hostname
Output ---> ip-14-222-22-28.us-west-2.compute.internal

2. hostname: hostname ---> linux command line
ip-14-222-22-28