-- user.data (new advance way to config ami linux inst ec2 to work on ddns)
note: 
 0. new instance installed with ddns capability (2016/12/20 14:51 v0 working)
 1. login to n4jj
 2. cd 00bsd_my_doc/aws/ddns/ddns
 3. check 00ReadME.txt and modify at most 2 files (4 files are needed: build.sh rc.conf secret secret.pri)
 4. put ddns.tgz into n4jj:/tmp for next bash to download

#!/bin/bash
cd ~ec2-user
curl -O http://199.102.79.18:8080/tmp/ddns.tgz
tar xfvz ddns.tgz
cd ddns
cat ./rc.local >> /etc/rc.local
# that's it. Done with bash


####### the following is as ref only ####### 

setup user.data when launch AMI Linux 
check file of this directory n4jj:~user/00bsd_my_doc/aws/ddns

ssh to n4jj
cd ~user/00bsd_my_doc/aws/
tar cfvz ~/tmp/trash/ddns.tgz ddns

back to ME (exit ssh)
scp -P 1234 user@n4jj:~/tmp/trash/ddns.tgz .
tar xfvz ddns.tgz

cd ddns
as root
vi ddns/make-ami-linux-ddns-work.sh
modify host variable to new name
cat rc.local >>  /etc/rc.local