aws_subnets Resource
Use the aws_subnets
InSpec audit resource to test properties of some or all subnets.
Subnets are networks within a VPC that can have their own block of IP address’s and ACL’s. VPCs span across all availability zones in AWS, while a subnet in a VPC can only span a single availability zone. Separating IP addresses allows for protection if there is a failure in one availability zone.
For additional information, including details on parameters and properties, see the AWS documentation on Subnets.
Install
This resource is available in the Chef InSpec AWS resource pack.
For information on configuring your AWS environment for Chef InSpec and creating an InSpec profile that uses the InSpec AWS resource pack, see the Chef InSpec documentation on the AWS cloud platform.
Syntax
An aws_subnets
resource block uses an optional filter to select a group of subnets and then tests that group.
# Test all subnets within a single vpc
describe aws_subnets.where(vpc_id: 'vpc-12345678') do
its('subnet_ids') { should include 'subnet-12345678' }
its('subnet_ids') { should include 'subnet-98765432' }
end
Parameters
This resource does not require any parameters.
Properties
subnet_ids
- The name of the auto scaling launch configuration associated with the auto scaling group.
vpc_ids
- An integer indicating the maximum number of instances in the auto scaling group.
cidr_blocks
- An integer indicating the minimum number of instances in the auto scaling group.
availability_zone
- The availability zone this subnet is part of.
map_public_ip_on_launch
- A boolean indicating if a public IP is automatically mapped to instances launched in this subnet.
states
- An array of strings corresponding to the subnet IDs associated with the auto scaling group.
entries
- Provides access to the raw results of the query, which can be treated as an array of hashes.
tags
- Array of arrays of hashes with existing tags.
Examples
Look for all subnets within a vpc.
describe aws_subnets.where(vpc_id: 'vpc-12345678') do
its('subnet_ids') { should include 'subnet-12345678' }
its('subnet_ids') { should include 'subnet-98765432' }
end
Examine a specific subnet.
describe aws_subnets.where(subnet_id: 'subnet-12345678') do
its('cidr_blocks') { should eq ['10.0.1.0/24'] }
end
Examine a specific vpcs Subnet IDs.
describe aws_subnets.where(vpc_id: 'vpc-12345678') do
its('states') { should_not include 'pending' }
end
Examine a specific subnets VPC IDS.
describe aws_subnets.where(subnet_id: 'subnet-12345678') do
its('vpc_ids') { should include 'vpc-12345678' }
end
Check existing tags.
describe aws_subnets.where(vpc_id: vpc_id) do
its('tags') { should include([{key: 'Name', value: 'My favourite subnet'}]) }
end
Matchers
For a full list of available matchers, visit the InSpec matchers page.
exist
The control will pass if the describe returns at least one result.
Use should_not
to test the entity should not exist.
describe aws_subnets.where( <property>: <value>) do
it { should exist }
end
describe aws_subnets.where( <property>: <value>) do
it { should_not exist }
end
AWS Permissions
Your Principal will need the EC2:Client:DescribeSubnetsResult
action with Effect
set to Allow
.
You can find detailed documentation at Actions, Resources, and Condition Keys for Amazon EC2.