fix(oncall): use selectors for OnCallShift membership in Schedules

grafanaplane/oncall/schedule.libsonnet

@@ -3,6 +3,7 @@ local xtd = import 'github.com/jsonnet-libs/xtd/main.libsonnet';
 
 local raw = import '../zz/main.libsonnet';
 local schedule = raw.oncall.v1alpha1.schedule;
+local onCallShift = raw.oncall.v1alpha1.onCallShift;
 local forProvider = schedule.spec.parameters.forProvider;
 
 {
@@ -47,17 +48,28 @@ local forProvider = schedule.spec.parameters.forProvider;
         d.argument.new('shifts', d.T.object, default='{}'),
       ]
     ),
-    new(name, shifts={}): {
+    new(name, shifts=[]): {
+      local this = self,
+
+      // For this schedule to refer to all of its related shifts, we must
+      // supply a single matchLabel selector. To do this, we construct a label
+      // to be applied to all child shifts, and match using that.
+      local shiftLabels = {
+        'oncall.grafana.net.namespaced/schedule-claim-name': this.scheduleName,
+      },
+
       scheduleName:: xtd.ascii.stringToRFC1123(name),
       schedule:
-        schedule.new(self.scheduleName)
+        schedule.new(this.scheduleName)
         + forProvider.withName(name)
         + forProvider.withType('calendar')
-        + forProvider.withShiftsRef([
-          forProvider.shiftsRef.withName(shift.metadata.name)
-          for shift in self.shifts
-        ]),
-      shifts: shifts,
+        + forProvider.shiftsSelector.withMatchLabels(shiftLabels),
+      shifts: [
+        // label each shift with the schedule-claim-name
+        onCallShift.metadata.withLabels(shiftLabels)
+        + shift
+        for shift in shifts
+      ],
     },
 
     '#withId':: d.func.new(