Trigger pipeline build from sub directory in a monorepo

Question

We're interested in moving a monorepo to git and would like to integrate it with a pipeline based CI/CD.

The general pattern we've seen so far is a single pipeline description file at the root of the repo, which implies a single pipeline per repo. This seems to be the pattern followed by Jenkins Pipeline, Gitlab, Bitbucket CI, CircleCI and others.

Given a monorepo, we would like multiple such files, one for each project in the repo.

Is there a pipeline style CI that does this?

The other alternative we can think of is a pipeline description file for all projects with custom filtering. Do any of the existing pipeline CI systems handle this without extra tooling?

Answer 1

One solution is to bring your own solution by checking all the projects impacted by the commits which the CI has checked-out.

Once you have your list of projects you run all the tasks you need to run on each one of the projects impacted by changes.

Answer 2

I created some showcase for monorepo with Gradle as build tool and CircleCI or Bitbucket pipelines as CI tool.

See: https://github.com/zladovan/monorepo

Gradle specific stuff should be replaceable quite easily by something else. Just change tools/ci/core/list-dependencies.sh.