Added script to release allocated-but-unassociated elastic IPs on AWS

deploy-cluster-aws/release_eips.py

@@ -0,0 +1,51 @@
+# -*- coding: utf-8 -*-
+"""Release all allocated but non-associated elastic IP addresses
+(EIPs). Why? From the AWS docs:
+
+``To ensure efficient use of Elastic IP addresses, we impose a small
+hourly charge if an Elastic IP address is not associated with a
+running instance, or if it is associated with a stopped instance or
+an unattached network interface. While your instance is running,
+you are not charged for one Elastic IP address associated with the
+instance, but you are charged for any additional Elastic IP
+addresses associated with the instance. For more information, see
+Amazon EC2 Pricing.''
+
+Source: http://tinyurl.com/ozhxatx
+"""
+
+from __future__ import unicode_literals
+import botocore
+import boto3
+from awscommon import get_naeips
+
+# Get an AWS EC2 "resource"
+# See http://boto3.readthedocs.org/en/latest/guide/resources.html
+ec2 = boto3.resource(service_name='ec2')
+
+# Create a client from the EC2 resource
+# See http://boto3.readthedocs.org/en/latest/guide/clients.html
+client = ec2.meta.client
+
+non_associated_eips = get_naeips(client)
+
+print('You have {} allocated elactic IPs which are '
+      'not associated with instances'.
+      format(len(non_associated_eips)))
+
+for i, eip in enumerate(non_associated_eips):
+    public_ip = eip['PublicIp']
+    print('{}: Releasing {}'.format(i, public_ip))
+    domain = eip['Domain']
+    print('(It has Domain = {}.)'.format(domain))
+    try:
+        if domain == 'vpc':
+            client.release_address(AllocationId=eip['AllocationId'])
+        else:
+            client.release_address(PublicIp=public_ip)
+    except botocore.exceptions.ClientError as e:
+        print('A boto error occurred:')
+        raise
+    except:
+        print('An unexpected error occurred:')
+        raise

docs/source/deploy-on-aws.md

@@ -122,9 +122,17 @@ bigchaindb --help
 bigchaindb show-config
 ```
 
-There are fees associated with running instances on EC2, so if you're not using them, you should terminate them. You can do that from the AWS EC2 Console.
+There are fees associated with running instances on EC2, so if you're not using them, you should terminate them. You can do that using the AWS EC2 Console.
 
-The same is true of your allocated elastic IP addresses. There's a small fee to keep them allocated if they're not associated with a running instance. You can release them from the AWS EC2 Console.
+The same is true of your allocated elastic IP addresses. There's a small fee to keep them allocated if they're not associated with a running instance. You can release them using the AWS EC2 Console, or by using a handy little script named `release_eips.py`. For example:
+```text
+$ python release_eips.py
+You have 2 allocated elactic IPs which are not associated with instances
+0: Releasing 52.58.110.110
+(It has Domain = vpc.)
+1: Releasing 52.58.107.211
+(It has Domain = vpc.)
+```
 
 ## Known Deployment Issues