I'm especially interested in a pipeline with parallel executions of different kinds of tests, maybe some manual checkpoint in there, a more complex chain with execution on different kinds of hosts or containers.
You can do all the things you've listed. But you can't build an arbitrarily complex DAG of tasks. Instead, you must order everything into a sequential list of 'stages'. Within a stage you have a list of jobs, which are run in parallel. This might be enough for your needs, but I'd like flexibility to express dependencies for each and every task, Say `t1 -> ((t2,t3),t4 -> t5) -> t6`, etc.
And it's a pain to propagate variables from one task to another, like say setting an environment variable in one task, and getting its value in a downstream task. You end up writing scripts to write them to a file, telling gitlab to make that file an 'artifact', and then reading it downstream.
And then there's the transient errors, all of which are listed on open issues. We're using the hosted gitlab.com, and on some of our CI pipelines, we have a dozen or some stages. The chances of a transient error, .e.g. a runner getting a 503 from gitlab.com, are pretty high.
Say I want something like this:
1. Sequential: stage "build", build-type agent.
2. Sequential: stage "tests" (this is just a wrapper/container)
2.1 Parallel: stage "integration tests #1", integration #1-type agent
2.2 Parallel: stage "integration tests #2, integration #2-type agent
2.3 Parallel: stage "deploy and functional tests" (this is just a wrapper/container)
2.3.1 Sequential: stage "deploy", deploy-type agent
2.3.2 Sequential: stage "functional tests", functional-type agent
https://docs.gitlab.com/ee/ci/pipelines.html#pipeline-graphs
For one of the software projects I'm involved in, I have more complex needs. We release binaries for multiple platforms so our Jenkins master delegates certain tasks to slaves running on specific OSes. Then at the end the Jenkins master downloads the built artifacts from all slaves and publishes everything to our artifact hosting server. As far as I can tell, Gitlab CI does not support this.
In future CI jobs I may even require user interaction, e.g. I may ask a human to sign off a report. I don't think Gitlab CI can do this.
But if your needs aren't so complex then Gitlab CI is great. It's UX-philosophically similar to Travis and setting it up is super simple, as opposed to Jenkins which is a pain to use.
GitLab CI/CD can certainly run jobs on different OSes, then have a final job consolidate those artifacts and publish to an artifact server. What part can't GitLab do?
> In future CI jobs I may even require user interaction, e.g. I may ask a human to sign off a report. I don't think Gitlab CI can do this.
GitLab CI/CD has manual jobs so a pipeline can wait for human sign off before proceeding.
Apache Groovy isn't "complete" as shipped with Jenkins. It's collections API is deliberately crippled so it doesn't work.
No manual checkpoints and different kinds of hosts or containers though.