flag previous generation instance types

src/cfnlint/rules/resources/PreviousGenerationInstanceType.py

@@ -0,0 +1,45 @@
+"""
+Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+SPDX-License-Identifier: MIT-0
+"""
+import re
+from cfnlint.rules import CloudFormationLintRule
+from cfnlint.rules import RuleMatch
+
+
+class PreviousGenerationInstanceType(CloudFormationLintRule):
+    id = 'I3100'
+    shortdesc = 'Checks for legacy instance type generations'
+    description = 'New instance type generations increase performance and decrease cost'
+    source_url = 'https://aws.amazon.com/ec2/previous-generation/'
+    tags = ['resources', 'ec2', 'rds', 'elasticcache', 'elasticsearch']
+
+    def match(self, cfn):
+        matches = []
+        for resource_type, property_type in [
+          ('AWS::AutoScaling::LaunchConfiguration', 'InstanceType'),
+          ('AWS::EC2::CapacityReservation', 'InstanceType'),
+          ('AWS::EC2::Host', 'InstanceType'),
+          ('AWS::EC2::Instance', 'InstanceType'),
+          ('AWS::RDS::DBInstance', 'DBInstanceClass'),
+          ('AWS::ElastiCache::CacheCluster', 'CacheNodeType'),
+          ('AWS::ElastiCache::GlobalReplicationGroup', 'CacheNodeType'),
+          ('AWS::ElastiCache::ReplicationGroup', 'CacheNodeType'),
+        ]:
+            for resource_name, resource in cfn.get_resources([resource_type]).items():
+                if isinstance(resource.get('Properties', {}).get(property_type, ''), str):
+                    if re.search(r'([cmr][1-3]|cc2|cg1|cr1|g2|hi1|hs1|i2|t1)\.', resource.get('Properties', {}).get(property_type, '')):
+                        matches.append(RuleMatch(['Resources', resource_name, property_type], 'Upgrade previous generation instance type: ' + resource.get('Properties').get(property_type)))
+
+        for resource_type, top_level_property_type, property_type in [
+          ('AWS::EC2::EC2Fleet', 'FleetLaunchTemplateOverridesRequest', 'InstanceType'),
+          ('AWS::EC2::LaunchTemplate', 'LaunchTemplateData', 'InstanceType'),
+          ('AWS::EC2::SpotFleet', 'SpotFleetLaunchSpecification', 'InstanceType'),
+          ('AWS::OpenSearchService::Domain', 'ClusterConfig', 'InstanceType'),
+          ('AWS::Elasticsearch::Domain', 'ElasticsearchClusterConfig', 'InstanceType'),
+        ]:
+            for resource_name, resource in cfn.get_resources([resource_type]).items():
+                if isinstance(resource.get('Properties', {}).get(top_level_property_type, {}).get(property_type, ''), str):
+                    if re.search(r'([cmr][1-3]|cc2|cg1|cr1|g2|hi1|hs1|i2|t1)\.', resource.get('Properties', {}).get(top_level_property_type, {}).get(property_type, '')):
+                        matches.append(RuleMatch(['Resources', resource_name, top_level_property_type, property_type], 'Upgrade previous generation instance type: ' + resource.get('Properties').get(top_level_property_type).get(property_type)))
+        return matches

test/fixtures/templates/bad/previous_generation_instances.yaml

@@ -0,0 +1,23 @@
+Resources:
+  Domain:
+    Type: AWS::Elasticsearch::Domain
+  Instance:
+    Type: AWS::EC2::Instance
+    Properties:
+      InstanceType: m1.small
+      ImageId: ami-abc
+  DBInstance:
+    Type: AWS::RDS::DBInstance
+    Properties:
+      DBInstanceClass: db.t1.micro
+  CacheCluster:
+    Type: AWS::ElastiCache::CacheCluster
+    Properties:
+      CacheNodeType: cache.r3.large
+      Engine: memcached
+      NumCacheNodes: 1
+  Domain2:
+    Type: AWS::Elasticsearch::Domain
+    Properties:
+      ElasticsearchClusterConfig:
+        InstanceType: m3.medium.elasticsearch

test/fixtures/templates/good/generic.yaml

@@ -73,7 +73,7 @@ Resources:
     Type: "AWS::EC2::Instance"
     Properties:
       ImageId: "ami-2f726546"
-      InstanceType: t1.micro
+      InstanceType: t3.micro
       KeyName: testkey
       IamInstanceProfile: !Ref RootInstanceProfile
       BlockDeviceMappings:
@@ -93,7 +93,7 @@ Resources:
     Type: "AWS::EC2::Instance"
     Properties:
       ImageId: "ami-2f726546"
-      InstanceType: t1.micro
+      InstanceType: t3.micro
       KeyName: testkey
       BlockDeviceMappings:
         - DeviceName: /dev/sdm

test/unit/module/test_rules_collections.py

@@ -49,7 +49,7 @@ def test_fail_run(self):
         filename = 'test/fixtures/templates/bad/generic.yaml'
         template = cfnlint.decode.cfn_yaml.load(filename)
         cfn = Template(filename, template, ['us-east-1'])
-        expected_err_count = 30
+        expected_err_count = 32
         matches = []
         matches.extend(self.rules.run(filename, cfn))
         assert len(matches) == expected_err_count, 'Expected {} failures, got {}'.format(

test/unit/rules/resources/test_previous_generation_instance_type.py

@@ -0,0 +1,18 @@
+"""
+Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+SPDX-License-Identifier: MIT-0
+"""
+from cfnlint.rules.resources.PreviousGenerationInstanceType import PreviousGenerationInstanceType  # pylint: disable=E0401
+from .. import BaseRuleTestCase
+
+
+class TestPreviousGenerationInstanceType(BaseRuleTestCase):
+    def setUp(self):
+        super(TestPreviousGenerationInstanceType, self).setUp()
+        self.collection.register(PreviousGenerationInstanceType())
+
+    def test_file_positive(self):
+        self.helper_file_positive()
+
+    def test_file_negative(self):
+        self.helper_file_negative('test/fixtures/templates/bad/previous_generation_instances.yaml', 4)