post-1.11-rebase: reenable event handling while image pruning

[miminar]

Underlying gonum/graph assigns conflicting IDs to new nodes after a node deletion. Thus two different nodes amy be assigned the same ID. This leads to panic when an edge is set between them.

The following PR temporarily disables event handling until the package is fixed. This ensures that no new nodes will be added to the graph after the first node gets removed.

deads2k#87

Either gonum/graph needs to be fixed or some replacement needs to be found.

The code is still buggy in 3.10 and needs to be fixed. The rebase just made the bug visible.

[miminar]

/cc @openshift/sig-developer-experience

[bparees]

we'll also need to fix this behavior in 3.10.z

[bparees]

Does gonum/graph allow us to generate our own ids?

[miminar]

Does gonum/graph allow us to generate our own ids?

Good idea. The generation is quite simple: https://github.com/openshift/origin/blob/master/vendor/github.com/gonum/graph/simple/directed.go#L51

We can use our own function though.

[openshift-bot]

Issues go stale after 90d of inactivity.

Mark the issue as fresh by commenting /remove-lifecycle stale.
Stale issues rot after an additional 30d of inactivity and eventually close.
Exclude this issue from closing by commenting /lifecycle frozen.

If this issue is safe to close now please do so with /close.

/lifecycle stale

[bparees]

/remove-lifecycle stale
/lifecycle frozen