Filtering ec2-instances with boto

Question

I use tags to keep track of my EC2 instances, such as (Project, Environment). I have a use case where I need to filter only those instances that belong to a specific project and to a specific environment.

When I use filter with boto and pass these two values I get a result that does a OR rather than a AND of the filters and so I am receiving a list of instances that belong to different projects but same environment.

Now I can use two lists and then compare the instances in each and get the desired set of instances, but is there a better way of getting this done?

Here is what i am doing:

conn = ec2.EC2Connection('us-east-1',aws_access_key_id='XXX',aws_secret_access_key='YYY')
reservations = conn.get_all_instances(filters={"tag-key":"project","tag-value":<project-name>,"tag-key":"env","tag-value":<env-name>})
instances = [i for r in reservations for i in r.instances]

Now the instance list that I am getting gives all the instances from the specified project irrespective of the environment and all the instances from the specified environment irrespective of the project.

Answer 1

You can use the tag:key=value syntax to do an AND search on your filters.

import boto.ec2

conn = boto.ec2.connect_to_region('us-east-1',aws_access_key_id='xx', aws_secret_access_key='xx')
reservations = conn.get_all_instances(filters={"tag:Name" : "myName", "tag:Project" : "B"})
instances = [i for r in reservations for i in r.instances]
print instances

See EC2 API for details http://docs.aws.amazon.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeInstances.html

The problem with the syntax you used is that a Python dict has unique keys, so the second tag-key entry overwrites the first one :-(

Seb