Puppet dry as part of cluster plan

[simonswine]

Is this a BUG REPORT or FEATURE REQUEST?:

/kind feature

What happened:

Using puppet we can do a proper dry-run of the changes that would have happen to the cluster. We currently don't expose that possibility through Wing's API server.

What you expected to happen:

We should have a separate API object in the Wing API to request a puppet run. We should record the output of the puppet command there and ensure that we can retrieve the output there.

[simonswine]

I think step one would be to write a proposal how that could work

[kragniz]

Initial thoughts on a proposal: have a PuppetManifest API object that as part of its spec contains:

• source, similar to kubernetes's VolumeSource, initially only with support for s3 buckets
• some kind of signature for verifying the manifests

The spec can include information about signature matching, puppet output from dry-run or apply.

Wing instances can have two fields to point at a PuppetManifest: appliedManifests and proposedManifests. These would run puppet apply or puppet dry-run ​respectively.

[simonswine]

@kragniz what is the state of that proposal?

[simonswine]

/assign @kragniz

Can you provide some update where we are at. I would like to take a look and it looks like I have the chance to do that Thu/Fri this week

[simonswine]

I think midterm we'd like to align to the Cluster API. If you look at their Types they have a similar approach to what kubernetes is doing with Pod <- ReplicaSets <- Deployment with their Machine <- MachineSet <- MachineDeployment. Not too sure it might be a good time for us to align to that.

https://github.com/kubernetes-sigs/cluster-api/blob/master/pkg/apis/cluster/v1alpha1/machine_types.go#L50
https://github.com/kubernetes-sigs/cluster-api/blob/master/pkg/apis/cluster/v1alpha1/machineset_types.go#L49
https://github.com/kubernetes-sigs/cluster-api/blob/master/pkg/apis/cluster/v1alpha1/machinedeployment_types.go#L50

Wdyt @kragniz