add cloudformation deletion script

Author: pranavgaikwad

.gitignore

@@ -26,7 +26,7 @@ share/python-wheels/
 .installed.cfg
 *.egg
 MANIFEST
-
+.vscode/
 # PyInstaller
 #  Usually these files are written by a python script from a template
 #  before PyInstaller builds the exe, so as to inject date/other infos into it.

aws/reporting/cloudformation.py

@@ -0,0 +1,52 @@
+import boto3
+import logging
+from common import get_all_regions
+
+DELETEABLE_STATUS = ["CREATE_FAILED", "DELETE_FAILED"]
+
+AWS_RESOURCE_TYPE_EC2_INSTANCE = "AWS::EC2::Instance"
+
+AWS_EKS_MANAGED_TAGS = ["alpha.eksctl.io/cluster-name"]
+
+logger = logging.getLogger(__name__)
+
+def get_deleteable_cf_templates(client):
+    deleteable_stacks = []
+    response = client.describe_stacks()
+    for stack in response.get('Stacks', []):
+        stackName = stack.get("StackName", "")
+        if stackName != "":
+            is_eks_managed = False
+            for tag in stack.get('Tags', []):
+                if tag.get('Key', '') in AWS_EKS_MANAGED_TAGS:
+                    is_eks_managed = True
+                    logger.info("{} Found EKS managed stack {}".format(client.meta.region_name, stackName))
+            if not is_eks_managed:
+                if stack.get('StackStatus', '') in DELETEABLE_STATUS:
+                    deleteable_stacks.append(stack)
+                    logger.info("{} Found stack with deleteable status {}".format(client.meta.region_name, stackName))
+                elif not does_cf_template_have_ec2_instances(client, stackName):
+                    deleteable_stacks.append(stack)
+                    logger.info("{} Found stack without instances {}".format(client.meta.region_name, stackName))
+    return deleteable_stacks
+
+def does_cf_template_have_ec2_instances(client, stack_name: str):
+    for resource in client.describe_stack_resources(StackName=stack_name)['StackResources']:
+        if resource.get('ResourceType', '') == AWS_RESOURCE_TYPE_EC2_INSTANCE:
+            return True
+    return False
+
+def delete_stacks(dry_run = False):
+    for region in get_all_regions():
+        client = boto3.client('cloudformation', region_name=region)
+        stacks = get_deleteable_cf_templates(client)
+        for stack in stacks:
+            stackName = stack.get("StackName", "")
+            if stackName != "":
+                try:
+                    logger.info("{} Attempting to delete stack {}".format(region, stackName))
+                    if not dry_run:
+                        client.delete_stack(StackName=stackName)
+                    logger.info("{} Deleted stack {}".format(region, stackName))
+                except:
+                    logger.info("{} Failed deleting stack {}".format(region, stackName))

aws/reporting/main.py

@@ -13,6 +13,7 @@
 from common import save_to_file, load_from_file
 from s3 import get_all_buckets, reformat_buckets_data
 from vpc import get_all_vpcs, delete_orphan_vpcs
+from cloudformation import delete_stacks
 
 # number of days to qualify an instance as old
 OLD_INSTANCE_THRESHOLD = 30
@@ -147,11 +148,11 @@ def get_old_instances_email_summary(oldInstancesSheet, allInstancesSheet, summar
         summary_email += "- {} unsaved instances owned by {} associated with GUIDs <b>{}</b><br>"\
                                     .format(v.get('count'), k, v.get('guids'))
     if len(orphan_instances) > 0:
-        summary_email += "\n Following instances could not be associated with owners:\n"
+        summary_email += "<br><br> Following instances could not be associated with owners:<br>"
         for inst in orphan_instances:
             summary_email += "- Instance Id : {}, Region : {}".format(inst['InstanceId'], inst['AvailabilityZone'])
     if total_ec2_deleted is not None:
-        summary_email += "\n Total EC2 instances deleted so far: <b>{}</b>".format(str(total_ec2_deleted))
+        summary_email += "<br><br> Total EC2 instances deleted so far: <b>{}</b><br>".format(str(total_ec2_deleted))
     return message.format(sheet_link, sheet_link, scheduled, summary_email)
 
 if __name__ == "__main__":
@@ -242,7 +243,8 @@ def get_old_instances_email_summary(oldInstancesSheet, allInstancesSheet, summar
     elif args[1] == 'purge_instances':
         numberOfInstancesDeleted = terminate_instances(oldInstancesSheet, allInstancesSheet)
         summaryRow['EC2 Cleanup'] = 'Deleted {} instances'.format(numberOfInstancesDeleted)
-    
+        delete_stacks()
+
     elif args[1] == 'generate_ec2_deletion_summary':
         summaryEmail = get_old_instances_email_summary(oldInstancesSheet, allInstancesSheet, summarySheet)
         if summaryEmail is not None: