### Problem to solve Currently we run auto devops automatically even for projects that: 1. Don't have a dockerfile 1. Don't have a matching buildpack This leads to unnecessary cycles and user dissatisfaction as they often don't understand why their project is showing failures. ### Target audience - Sasha, Software Developer, https://design.gitlab.com/research/personas#persona-sasha - Devon, DevOps Engineer, https://design.gitlab.com/research/personas#persona-devon ### Further details <!--- Include use cases, benefits, and/or goals (contributes to our vision?) --> ### Proposal When Auto DevOps is enabled, evaluate if a build mechanism exists before running. If no build mechanism, disable Auto DevOps. Mechanisms to consider should include: 1. Presence of a `Dockerfile` 1. Presence of matching file for buildpack `bin/detect` (ie `Gemfile` for Ruby, `package.json` for node.js, etc). We'll just need to hardcode all the files listed in `bin/detect` for all the supported buildpacks. 1. Presence of a custom `BUILDPACK_URL` environment variable This should only happen when Auto DevOps is "implicitly" enabled and not when explicitly enabled as someone that has explicitly enabled Auto DevOps will want to see a failing pipeline to understand why it's not working. We should also ensure the logic to check if the files exist is based on the SHA for which we are currently creating a pipeline (and not just looking at `master` for example). Lastly, if the check runs and no Dockerfile or matching buildpack are found AND Auto DevOps has been enabled implicitly for the project in question, we should inform user about this fact in the Auto DevOps settings section by displaying a [warning alert](https://design.gitlab.com/components/alerts) that reads: > You must add a Dockerfile or supported buildpack in order for the Auto DevOps pipeline to run. [More information](https://docs.gitlab.com/ee/topics/autodevops/#auto-build)  If the correct file is added, we should automatically run the pipeline. ### What does success look like, and how can we measure that? We should track the instances where this evaluation returned true or false to start. ### Links / references <!-- triage-serverless v3 PLEASE DO NOT REMOVE THIS SECTION --> *This page may contain information related to upcoming products, features and functionality. It is important to note that the information presented is for informational purposes only, so please do not rely on the information for purchasing or planning purposes. Just like with all projects, the items mentioned on the page are subject to change or delay, and the development, release, and timing of any products, features, or functionality remain at the sole discretion of GitLab Inc.* <!-- triage-serverless v3 PLEASE DO NOT REMOVE THIS SECTION -->