I need to create a python lambda function which check a set of conditions. One of the is to count the number of running ec2 instances with a specific name from another aws account.

I searched stackoverflow and found something like this, but this should only count the instances from the same account/region.

def ec2(event, context):
ec2_resource = boto3.resource('ec2')
instances = [instance.state['Name'] for instance in ec2_resource.instances.all()]
ec2_running_instances = instances.count('running')
print(ec2_running_instances)

CodePudding user response：

You can't do this directly from your account. You must assume IAM role that is created in the second account, with permissions to describe the instances. Please check: Delegate access across AWS accounts using IAM roles .

Once the role exists, you have to use boto3's assume_role to assume the role, get temporary aws credentials, and then create new boto3 session with that credentials.