RoRCraft - Ruby on Rails - Value driven web development

To enable the static IP addresses function , you need to download the latest Amazon EC2 Command-Line Tools, the download link of it is http://developer.amazonwebservices.com/connect/entry.jspa?externalID=351&categoryID=88

after download, I recommend to unzip it to a folder call ec2 under your home path

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mkdir ~/ec2
cd ~/ec2
unzip ec2-api-tools.zip

you can now see a folder call ec2-api-tools-1.3-19403 under the ec2 folder.

now it is time to update the .profile , so that EC2 tool can find the library that it use.

you have to download the private and public cert from amazon

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nano ~/.profile
export PATH=~/ec2/ec2-api-tools-1.3-19403/bin:$PATH
export EC2_HOME=~/ec2/ec2-api-tools-1.3-19403
export EC2_CERT=~/.ec2/cert-xxxxxxxxx.pem
export EC2_PRIVATE_KEY=~/.ec2/pk-yyyyyy.pem

then you can start a new console so that the profile update will be effective.

you can now allocate a new IP address for your account.

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Chris:~ chrischan$ ec2-allocate-address 
ADDRESS 75.101.139.212

This new IP 75.101.140.212 is not bundle to any AMI instance yet.
You have to manually assign this IP address to a instance

First, you need to know the instance that you have already started. you can use the following command

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Chris:~ chrischan$ ec2-describe-instances 
  RESERVATION     r-3c1bea55      073126868754    default
INSTANCE        i-7124dd30      ami-5035d079    ec2-67-202-34-115.compute-1.amazonaws.com      
domU-12-31-38-00-6D-98.compute-1.internal       running         0m1.small 2008-03-05T15:51:36+0000 
us-east-1a

you can see that the instance id is i-7124dd30, we can then assign the IP to that instance

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Chris:~ chrischan$ ec2-associate-address 75.101.140.212 -i i-7124dd30
ADDRESS 75.101.140.212  i-7124dd30

If you want to check the address allocation status, you can use the follow command

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Chris:~ chrischan$ ec2-describe-addresses 
ADDRESS 75.101.140.212  i-7124dd30

for any time if you want to free the IP , you can use

ec2-release-address IP-address

If you want to assign the existing IP address to a new instance , you can use ec2-associate-address, but this time , you assign the new instance IP, and the existing IP address bundling will remove, so the single IP address will always only bundle to one instance.

Also, a instance can only have one IP address assocate to it , so when you assign a new IP address to a instance, all the existing IP bundling will be removed. And all the IP address in this status will start to charge you account. So whenever any IP allocate has finished , please make to use ec2-describe-addresses to check the IP address bundling status.