jenkinsci / pipeline-milestone-step-plugin

Pipeline Milestone Step Plugin

Provides the milestone step in Pipeline scripts.

By default, Pipeline builds can run concurrently. The milestone step ensures an older build will not override a newer build, so the older build will never be allowed to pass a milestone (it is aborted) if a newer build already passed it.

This step is specially useful in Continuous Delivery pipelines, where builds ordering is very important as the order defines what is going to be delivered, so it provides a control point that aborts any build trying to deliver an old commit when a newer one is already being delivered.

In general this step grants:

• Builds pass milestones in order (taking the build number as sorter field).
• Older builds will not proceed (they are aborted) if a newer one already passed the milestone.
• When a build passes a milestone, any older build that passed the previous milestone but not this one is aborted (see TIP 2 below).

There are two optional parameters:

• ordinal: sequential number which makes milestones comparable. For any given two consecutive milestones, ordinal for the second milestone must be a greater integer than the ordinal for the first one. If not specified an auto-incremented ordinal is internally generated.
• label: just for displaying purposes in Pipeline visual representations (provided by other plugins).

This examples are both valid:

milestone 1
... pipeline code here

milestone 2
... more pipeline code

milestone 3
... and more

milestone 100
... pipeline code here

milestone 200
... more pipeline code

milestone 300
... and more

TIP 1: A combination of this step and the lock step can be used to configure a reliable Continuous Delivery pipeline as both delivering latest code status and unique deployments are granted. There is an example of this pattern in the Pipeline CD demo Jenkinsfile.

TIP 2: retroactive builds abort, which is older builds being cancelled once a newer one passes a milestone that the older builds has not passed yet. For example, given this script:

milestone 1
input message: 'Continue?'
milestone 2

If three builds (#1, #2 and #3) start concurrently they are all going to stop on input step waiting for user interaction. If the user allows build #3 to proceed (so it passes milestone 2) then builds #2 and #1 will be automatically cancelled.