Does boto3 ec2 instances filter have equivalent to AWS CLI --query

Question

I started by using the AWS CLI to create a bash script to get the data I wanted about my instances. The main line being:

aws ec2 describe-instances --filter "Name=instance-state-name,Values=running" --query Reservations[*].Instances[*].[PublicDnsName,PublicIpAddress,PrivateIpAddress,BlockDeviceMappings[*].DeviceName] --output text

Then I realised I wanted something more complex so switched to python and boto3

ec2 = boto3.resource('ec2')
    instances = ec2.instances.filter(
        Filters = [ {
            'Name' : 'instance-state-name',
            'Values' : [ 'running' ]
        } ]
    )
for i in instances:
    """ The whole data set is here """
    print(i.public_dns_name)
    print(i.public_ip_address)
    """ etc """

I can traverse the response and get the data out but the boto3 version seems quite wasteful as I don't need most of the data that is being returned.

Can I get the boto3 interface to only return the data I am interested in, similar to the way the AWS CLI does using --query? (My assumption here being that the AWS CLI is not just getting the entire response and parsing it).

Answer 1

"filter - does filtering at the AWS level and returns the response. query - filters the results returned from AWS based on JMESPath query expressions"

I had also confirmed the same using tcpdump. The same data is returned from the server regardless of the contents of the --query parameter.