Add env variable to Job created by JobSink for the file path to the event

[Cali0707]

Problem
With the current way that a Job is created in the JobSink, there is some logic that chooses which VolumeMount to use to mount the event. As such, the path that the event is mounted at is not guaranteed to be the same for every Job created by a JobSink.

The JobSink should add an env variable K_EVENT_PATH into the container that points to the mount path of the volume which is chosen, making it easier to consume the event within the code of the job.

Here, we can inject the env variable before creating the job based on where the jobsink-event volume directory points to

eventing/cmd/jobsink/main.go

Lines 292 to 299 in f9156c8

	job := js.Spec.Job.DeepCopy()
	job.Name = jobName
	if job.Labels == nil {
	job.Labels = make(map[string]string, 4)
	}
	job.Labels[sinks.JobSinkIDLabel] = id
	job.Labels[sinks.JobSinkNameLabel] = ref.Name
	job.OwnerReferences = append(job.OwnerReferences, or)

Persona:
Which persona is this feature for? Developers

Exit Criteria
A measurable (binary) test that would indicate that the problem has been resolved.

Time Estimate (optional):
How many developer-days do you think this may take to resolve? 1

[Cali0707]

cc @pierDipi - thoughts?

[Cali0707]

/good-first-issue

[knative-prow]

@Cali0707:
This request has been marked as suitable for new contributors.

Please ensure the request meets the requirements listed here.

If this request no longer meets these requirements, the label can be removed
by commenting with the /remove-good-first-issue command.

In response to this:

/good-first-issue

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[babugeet]

/assign

[babugeet]

@Cali0707 , @pierDipi I would like to work on this issue

[Cali0707]

Closing as #7968 is merged