Complex and long single-job Jenkins Job Pipleine Builds: There yet?

[Martin Ba]

Hi all.

Been thinking on trying to migrate some of our stuff to Pipeline, *but*:

http://stackoverflow.com/questions/39905978/complex-and-long-single-job-jenkins-job-pipleine-builds-there-yet

# TL;DR

Does it make sense to have one *single* Jenking Job Pipeline job for a
full long-running deployment / "build" chain in the free Jenkins, given
that resumable `checkpoint`s are not available?

# Prelude

I'm looking at the current incarnation of [Jenkins'][1] the open/free
[Pipeline Bundle][2].

I'll note that I think that what you get for *free* here is quite simply
amazing, seeing as most of the stuff (workflow-jobs themselves,
[stage-view][3], ...) was only part of the commercial enterprise bundle
of CloudBees a year or two back.

# Single and Multiple Jobs

It also seems to me that given the [`stash`ing][4] abilities and
multi-node capabilities of the Jenkins Pipleine, it is -- and indeed is
advertised as such -- possible to create a *full* and complete
Build/Test/Bundle/Deploy chain in *one single* Jenkins job.

This is in contrast to the ["historical"(?) Build Pipeline Plugin][5]
that let you split "stages" across multiple Jenkins Jobs. Orchestrating
these jobs has always been abit of a hassle, not to mention passing
artifacts between the jobs and controlling how they run on different nodes.

# Repeat/Resume step

Except that what you *do* get from the Old Build Pipeline Plugin is
being able to restart a "stage" (when it fails) -- this works because a
"stage" is simply a Jenkins Job Run that you can repeat (and it will
also run all the downstream stuff).

# When Repeat/Resume is crucial

Our project's C++ Builds have compilation durations of hours, Automated
Tests that run longer hours and finally packaging and setup creation
that also isn't done in a few minutes.

If I do a "pipleine-build", if the setup creation at the end fails due
to setup-creation related problems, I do *not* want to rebuild the
project and re-run the unit tests. I want to fix the setup scripts and
redo the setup creation, that would (hopefully) wrap up this run with
success. ... Or, if some automated tests fail for, e.g., suspected build
environment reasons, I want to fix the build environment and re-run my
pipeline *from* the failed test forward, without doing a multi-hour
recompilation first.

# Checkpoint

It so happens that the New Jenkins Job Pipeline bundle *does* have the
ability to start from a [`checkpoint`][6]. Except: It's part of the
Enterprise Bundle which means it's not free. _{(I'll note that I'd be
*fine* with giving money to CloudBees, but I'm *not* fine with moving a
use-as-many-nodes-as-you-like-and-also-be-able-to-just-do-testruns-wherever-you-like
open software to a restricted licensed software where I have to keep
track of number of nodes, make sure test environments can even be setup
license-wise, etc.)}

# The Question: No checkpoint - means still multijob?

So, given that for me the New Jenkins Job Pipeline *doesn't* have the
ability to resume from a failed step, it *seems* I'm back to square one
and I have to split my longer-running stuff into multiple jobs anyway.

This then begs the question whether the Jenkins Job Pipleine is really
the best tool for the job -- if I have to orchestrate multiple jobs and
I want to streamline and automate this on the creation side, I could
just as well use the [Job DSL Plugin][7] to maintain all these jobs from
a single point -- and then the question is whether "free style" jobs
wouldn't do the job just as well.

On the other hand I might be missing something here and there is another
good single Job approach for this?

I'll note the `Replay` option for a Pipeline run looks promising, if a
bit crude ...


[1]: https://jenkins.io/
[2]: https://jenkins.io/doc/book/pipeline/overview/
[3]:
https://wiki.jenkins-ci.org/display/JENKINS/Pipeline+Stage+View+Plugin
[4]:
https://www.cloudbees.com/blog/parallelism-and-distributed-builds-jenkins
[5]: https://wiki.jenkins-ci.org/display/JENKINS/Build+Pipeline+Plugin
[6]:
https://go.cloudbees.com/docs/cloudbees-documentation/cje-user-guide/chapter-workflow.html?q=checkpoints
[7]: https://wiki.jenkins-ci.org/display/JENKINS/Job+DSL+Plugin