stolonctl: don't show null cluster spec options

[viggy28]

Submission type

• Bug report

Stolon version

v0.13.0 (and the recent commit too)

Unable to remove these parameters additionalWalSenders, additionalMasterReplicationSlots & automaticPgRestart from cluster spec.

Expected behaviour you didn't see

As per https://github.com/sorintlab/stolon/blob/master/doc/cluster_spec.md, patching cluster spec with null should remove the parameter whereas it didn't happen

Steps to reproduce the problem

Cluster spec already has default value of
"additionalWalSenders": null, "additionalMasterReplicationSlots": null, and "automaticPgRestart": null.

stolonctl --cluster-name stolon-cluster --store-backend=etcdv3 update --patch '{"automaticPgRestart":null}' doesn't do anything.

It's likely that

stolon/internal/cluster/cluster.go

Line 290 in 14bc547

AutomaticPgRestart *bool `json:"automaticPgRestart"`

omitempty is not mentioned in the JSON tag.

[sgotti]

@viggy28 I think that what's confusing is that they are printed as null during a stolonctl spec. They were really removed (so I'm going to change your title) and there's no bug or issue on this side.

omitempty will avoid showing them as null when marshalled to json and print.

[sgotti]

Fixed by #736