From c0c5d0334b0e573f3b14674a2e9fb68bca84b4d1 Mon Sep 17 00:00:00 2001 From: joey Date: Sat, 17 Aug 2024 22:11:29 +0800 Subject: [PATCH] TEP-0158: pipeline fail fast Signed-off-by: chengjoey --- teps/0158-pipeline-fail-fast.md | 160 ++++++++++++++++++++++++++++++++ 1 file changed, 160 insertions(+) create mode 100644 teps/0158-pipeline-fail-fast.md diff --git a/teps/0158-pipeline-fail-fast.md b/teps/0158-pipeline-fail-fast.md new file mode 100644 index 000000000..abe58f2a0 --- /dev/null +++ b/teps/0158-pipeline-fail-fast.md @@ -0,0 +1,160 @@ +--- +status: implementable +title: Pipeline fail-fast +creation-date: '2024-08-17' +last-updated: '2024-08-17' +authors: +- '@chengjoey' +--- + +# TEP-0158: Pipeline fail-fast + + +- [Summary](#summary) +- [Motivation](#motivation) + * [Goals](#goals) + * [use-cases](#use-cases) +- [Proposal](#proposal) + * [failFast](#failfast) + * [config-defaults](#config-defaults) + * [PipelineRun](#pipelinerun) + * [Pipeline](#pipeline) +- [Design Evaluation](#design-evaluation) + * [Priority](#priority) + * [Performance](#performance) +- [References](#references) + + + +## Summary + +This proposal is to support stopping the execution of the Pipeline immediately when a Task in the Pipeline failed. +Because there may be multiple parallel tasks in the pipeline, when one task fails, +The final status of the pipeline is Failed, but other tasks may still be executed, +which will waste resources. Therefore, we need a mechanism to support the +immediate stop of pipeline execution when a task failed. + +## Motivation + +When a Task in a Pipeline fails, the Pipeline status may eventually change to Failed, but other parallel Tasks continue to execute. +When the final Pipeline status is Failed, There is a high probability that users will create a new Pipeline execution, +because in many cases they hope that the final Pipeline status will be Success. Therefore, +in this case, it is necessary to stop the Pipeline execution as soon as possible. The fail-fast mechanism can +reduce the waste of resources on the one hand, and on the other hand, +it can also let users know the execution results of the Pipeline as soon as possible. + +### Goals + +- Support canceling the execution of the Pipeline immediately when a Task in the Pipeline failed. + +### use-cases + +Take the following pipeline as an example. When `fail-task` fails to execute, +the parallel `success1` and `success2`Tasks will exit execution. +The status of PipelineRun is `Failed`, the status of `fail-task` is `Failed`, +and the status of `success1` and `success2` are `RunCancelled`. + +```yaml +apiVersion: tekton.dev/v1 +kind: PipelineRun +metadata: + name: pipeline-run +spec: + failFast: "true" + pipelineSpec: + tasks: + - name: fail-task + taskSpec: + steps: + - name: fail-task + image: busybox + command: ["/bin/sh", "-c"] + args: + - exit 1 + - name: success1 + taskSpec: + steps: + - name: success1 + image: busybox + command: ["/bin/sh", "-c"] + args: + - sleep 360 + - name: success2 + taskSpec: + steps: + - name: success2 + image: busybox + command: ["/bin/sh", "-c"] + args: + - sleep 360 +``` + +## Proposal + +### failFast + +The `failFast` property is of string type and supports the following values: +1. `true`: When a Task in the Pipeline fails, the Pipeline execution is stopped immediately. +2. `false`: This is consistent with the current behavior. When a Task in a Pipeline fails, the Pipeline status changes to Failed, but other Tasks continue to execute. + +### config-defaults + +Add the `default-fail-fast` field in `config-defaults` to set the default fail-fast attribute for all Pipelines. + +```yaml +apiVersion: v1 +kind: ConfigMap +metadata: + name: config-defaults + namespace: tekton-pipelines +data: + # Default fail-fast attribute for all Pipelines + default-fail-fast: "true" +``` + +### PipelineRun + +Add the `failFast` field in PipelineRun to set the fail-fast property of the PipelineRun at runtime. + +```yaml +apiVersion: tekton.dev/v1 +kind: PipelineRun +metadata: + name: pipeline-run +spec: + failFast: "true" + pipelineSpec: + ... +``` + +### Pipeline + +Add the `failFast` field in Pipeline to set the fail-fast property of Pipeline. + +```yaml +apiVersion: tekton.dev/v1 +kind: Pipeline +metadata: + name: "demo.pipeline" +spec: + failFast: "true" + tasks: + ... +``` + +## Design Evaluation + +### Priority + +The `failFast` priority is：PipelineRun > Pipeline > config-defaults + +### Performance + +PipelineRun status is `Failed`, failed Task status is `Failed`, and other parallel Task status is `RunCancelled`. +When a Task fails, the Cancel event is triggered to cancel the execution of PipelineRun. + +## References + +* Implementation Pull Requests: + * [Tekton Pipelines PR #7987 - support fail-fast for PipelineRun][pr-7987] +* [Tekton Pipelines Issue #7880][issue-7880]