Odin, or Wōtan, is a Norse god who directs the valkyries and is the guardian of Valhalla. Half of those who perish in combat are welcomed by him into his majestic halls where they prepare for the final battle against Fenrir during the events of Ragnarök.
This serverless application periodically checks the status of CloudFormation stacks in the AWS account and region where it is deployed and sends the stale, removable ones to Valhalla by deleting them.
Odin determines that a stack should be removed when it's current state matches the following three criteria:
- Tagging: If a stack is not tagged with any of the stages specified as permanent in odin.yml then it is eligible for removal
- Status: If a stack's status is not one of those specified as off-limits in odin.yml then it is eligible for removal
- Age: If a stack has not been updated within the timeframes specified in odin.yml then it is eligible for removal
To change the frequency with which Odin runs and the settings used to determine whether a stack is eligible for deletion modify the values in odin.yml and redeploy the application.
Odin is built with the Serverless Framework - see their documentation for more about the tool and how to use it.
Odin uses Lumigo as a serverless monitoring and logging solution. To package and deploy the application with the Lumigo integration you'll need to setup an account and provide a Lumigo access token either as an environment variable or in a local .env file:
LUMIGO_TOKEN=<token>
There are instructions for setting up your Lumigo account and configuring the Lumigo serverless plugin.
If you don't want to include the integration you can comment out the Lumigo plugin in serverless.yml, and optionally comment out the Lumigo-specific configurations:
plugins:
- serverless-webpack
- serverless-cloudformation-resource-counter
- serverless-plugin-iam-checker
- serverless-plugin-test-helper
- serverless-prune-plugin
# - serverless-lumigo
# (commenting out the custom config is optional)
custom:
...
# https://github.com/lumigo-io/serverless-lumigo-plugin
# lumigo:
# token: ${env:LUMIGO_TOKEN}
# nodePackageManager: npmInstall dependencies:
npm i
Run unit test:
npm test
Deploy Odin:
npm run deploy
Deploy Odin to a specific stage using a named AWS profile:
npm run deploy -- --stage <stage> --aws-profile <profile>
Unlike his Norse namesake Odin is unable to practice magic and cannot remove stacks that aren't self-removing.
A common example of this situation is a stack which creates an S3 bucket that is later filled with files. If the stack doesn't contain the custom resources necessary to empty and then delete this bucket any stack delete commands (whether triggered by Odin, manually, or any other means) will end with the stack in an error state. Don't treat your stacks this way - let them enter Valhalla with honor!
To help with this, by default Odin will empty all S3 buckets in a stack prior to calling the delete stack command. You can either disable bucket emptying entirely or specify specific buckets to be emptied in the odin.yml config file.
schedule:
# This schedule initiates Odin once a day in the early morning (US ET) to clean up ephemeral stages
daily:
rate: cron(0 8 ? * * *) # 8 AM UTC / 3 AM ET
# This schedule initiates Odin every hour to clean up ephemeral stages
hourly:
rate: cron(0 */1 ? * * *) # every hour
dynamicRules:
daily:
staleAfter: 2 # When running the daily check, delete a stack if its older than 2 hours
hourly:
staleAfter: 8 # When running the hourly check, delete a stack if its older than 8 hours
# All of these rules are consistent between the schedules
staticRules:
# Odin won't delete a stack with the following names (case insensitive, partial matches)
namesToRetain:
- ControlTower
- LumigoIntegrationV2
# Odin won't delete a stack with the following stages (case insensitive, full matches only)
stagesToRetain:
- PROD
- PRODUCTION
- QA
- STAGING
- DEVELOPMENT
- DEV
- AUTO
- AUTOMATION
- INFRA
- INFRASTRUCTURE
- COMMON
# Odin will only delete a stack if it's status is one of the following
deleteableStatuses:
- CREATE_COMPLETE
- ROLLBACK_COMPLETE
- UPDATE_COMPLETE
- UPDATE_ROLLBACK_COMPLETE
# A CloudFormation stack won't delete successfully if there are non-empty buckets associated with it.
# Use this property to indicate whether or not you want Odin to empty all buckets in the stack
# (default behavior). If you only want Odin to empty specific buckets then set this property to false
# and update the bucketsToEmpty property below with the logical resource ids of the buckets you want
# Odin to empty.
emptyAllBuckets: true
# Odin will empty buckets with the following CloudFormation logical IDs (if you don't want to empty
# all buckets)
bucketsToEmpty:
- ServerlessDeploymentBucket
- DocumentBucket
- S3BucketSite
- ApiDocumentationBucketConfig specifications can be found (and modified) in odin.yml
From a CloudWatch Schedule event:
{
"namesToRetain": ["ControlTower", "LumigoIntegrationV2"],
"stagesToRetain": [
"PROD",
"PRODUCTION",
"QA",
"DEVELOPMENT",
"DEV",
"AUTO",
"AUTOMATION",
"INFRA",
"INFRASTRUCTURE",
"COMMON"
],
"deleteableStatuses": ["CREATE_COMPLETE", "ROLLBACK_COMPLETE", "UPDATE_COMPLETE", "UPDATE_ROLLBACK_COMPLETE"],
"emptyAllBuckets": true,
"bucketsToEmpty": ["ServerlessDeploymentBucket", "DocumentBucket", "S3BucketSite", "ApiDocumentationBucket"],
"staleAfter": 2
}Payload pulled from an SNS event:
{
"stackName": "stack-to-delete",
"config": {
"namesToRetain": ["ControlTower", "LumigoIntegrationV2"],
"stagesToRetain": [
"PROD",
"PRODUCTION",
"QA",
"DEVELOPMENT",
"DEV",
"AUTO",
"AUTOMATION",
"INFRA",
"INFRASTRUCTURE",
"COMMON"
],
"deleteableStatuses": ["CREATE_COMPLETE", "ROLLBACK_COMPLETE", "UPDATE_COMPLETE", "UPDATE_ROLLBACK_COMPLETE"],
"emptyAllBuckets": true,
"bucketsToEmpty": ["ServerlessDeploymentBucket", "DocumentBucket", "S3BucketSite", "ApiDocumentationBucket"],
"staleAfter": 2
}
}Generated using npm run project-stats:
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-------------------------------------------------------------------------------Murray, Alexander (1874). Manual of Mythology : Greek and Roman, Norse, and Old German, Hindoo and Egyptian Mythology. London, Asher and Co. This illustration is from plate XXXV. Digitized version of the book by the Internet Archive, https://archive.org/details/manualofmytholog00murruoft Published earlier in Reusch, Rudolf Friedrich. 1865. Die nordischen Göttersagen.