Cluster Service Perpetual Listening Loop

A perpetual for loop is spawned for the Cluster Service which - amongst other cases - monitor for an event type of ManifestReceived.

Following a series of validations - for example ensuring that the deployment pre-exists in which would indicate a deployment update event and assurance that the deployment exist in inventory - when passed thru eventually reaches a call of the newDeploymentManager function.

loop:
    for {
        select {
        ....
        case ev := <-s.sub.Events():
            switch ev := ev.(type) {
            case event.ManifestReceived:
                s.log.Info("manifest received", "lease", ev.LeaseID)

                mgroup := ev.ManifestGroup()
                if mgroup == nil {
                    s.log.Error("indeterminate manifest group", "lease", ev.LeaseID, "group-name", ev.Group.GroupSpec.Name)
                    break
                }

                if _, err := s.inventory.lookup(ev.LeaseID.OrderID(), mgroup); err != nil {
                    s.log.Error("error looking up manifest", "err", err, "lease", ev.LeaseID, "group-name", mgroup.Name)
                    break
                }

                key := ev.LeaseID
                if manager := s.managers[key]; manager != nil {
                    if err := manager.update(mgroup); err != nil {
                        s.log.Error("updating deployment", "err", err, "lease", ev.LeaseID, "group-name", mgroup.Name)
                    }
                    break
                }

                s.managers[key] = newDeploymentManager(s, ev.LeaseID, mgroup, true)