{"id":24012847,"url":"https://github.com/glassechidna/cloudformation-townclock","last_synced_at":"2026-06-13T08:32:40.729Z","repository":{"id":84300187,"uuid":"113517253","full_name":"glassechidna/cloudformation-townclock","owner":"glassechidna","description":"A helper to ensure that CloudFormation stacks can be keep \"fresh\" with a minimum of fuss","archived":false,"fork":false,"pushed_at":"2017-12-08T01:46:08.000Z","size":3,"stargazers_count":1,"open_issues_count":0,"forks_count":1,"subscribers_count":5,"default_branch":"master","last_synced_at":"2025-02-25T15:50:31.927Z","etag":null,"topics":["aws","cloudformation","lambda","parameter-store","ssm"],"latest_commit_sha":null,"homepage":null,"language":null,"has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":null,"status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/glassechidna.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":null,"code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null}},"created_at":"2017-12-08T01:36:31.000Z","updated_at":"2021-03-02T21:27:01.000Z","dependencies_parsed_at":null,"dependency_job_id":"4b48c884-3bb4-43b0-b645-918c99d49848","html_url":"https://github.com/glassechidna/cloudformation-townclock","commit_stats":null,"previous_names":[],"tags_count":0,"template":false,"template_full_name":null,"purl":"pkg:github/glassechidna/cloudformation-townclock","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/glassechidna%2Fcloudformation-townclock","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/glassechidna%2Fcloudformation-townclock/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/glassechidna%2Fcloudformation-townclock/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/glassechidna%2Fcloudformation-townclock/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/glassechidna","download_url":"https://codeload.github.com/glassechidna/cloudformation-townclock/tar.gz/refs/heads/master","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/glassechidna%2Fcloudformation-townclock/sbom","scorecard":null,"host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":286080680,"owners_count":34278153,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2026-05-26T15:22:16.424Z","status":"online","status_checked_at":"2026-06-13T02:00:06.617Z","response_time":62,"last_error":null,"robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":true,"can_crawl_api":true,"host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["aws","cloudformation","lambda","parameter-store","ssm"],"created_at":"2025-01-08T06:22:03.944Z","updated_at":"2026-06-13T08:32:40.710Z","avatar_url":"https://github.com/glassechidna.png","language":null,"funding_links":[],"categories":[],"sub_categories":[],"readme":"# CloudFormation Town Clock\n\n## Why\n\nSometimes you have a [Lambda-backed CloudFormation custom resource][lambda-cfn] reference in your template.\nCloudFormation only invokes the Lambda function when one of its inputs change. This is _usually_ the desired\nbehaviour, but sometimes you want the Lambda to be invoked every time the stack is updated. This is usually\nachieved by passing a \"dummy\" parameter to the resource that changes each time: timestamps and incrementing\nbuild numbers are popular choices. This project provides a simpler alternative.\n\n[lambda-cfn]: http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/template-custom-resources-lambda.html\n\n## Usage\n\nFirstly, create a new CloudFormationstack in your account based on [`townclock.yml`](/townclock.yml). \n\nNext, anywhere you have a Lambda-backed custom resource that you want invoked on every stack update, add \nthe following:\n\n```yaml\nParameters:\n  TownClock:\n    Type: AWS::SSM::Parameter::Value\u003cString\u003e\n    Default: /TownClock\n    Description: Dummy parameter to keep things updating.\nResources:\n  CustomResource:\n    Type: Custom::YourResource\n    Properties:\n      ServiceToken: # your lambda arn\n      # your normal properties..\n      DummyProperty: !Ref TownClock\n```\n\nTada, all done. Every stack update will now trigger a Lambda invocation.\n\n## How\n\nThe [`townclock.yml`](/townclock.yml) CloudFormation template will create an SSM parameter called \n\"TownClock\" (by default), a Lambda function that updates it and a CloudWatch Events rule to execute \nthat Lambda. Every time a stack is updated or a changeset is created, CloudFormation checks Parameter\nStore to see if the value has changed. If it's been more than a minute since the last update, the \nLambda will have updated the parameter's value.\n\n\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fglassechidna%2Fcloudformation-townclock","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fglassechidna%2Fcloudformation-townclock","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fglassechidna%2Fcloudformation-townclock/lists"}