feat(plan): allow plan to have multiple policies (#204)

controller/controller.go

@@ -54,9 +54,9 @@ func (c *Controller) RunOnce() error {
 	}
 
 	plan := &plan.Plan{
-		Policy:  c.Policy,
-		Current: records,
-		Desired: endpoints,
+		Policies: []plan.Policy{c.Policy},
+		Current:  records,
+		Desired:  endpoints,
 	}
 
 	plan = plan.Calculate()

plan/plan.go

@@ -28,8 +28,8 @@ type Plan struct {
 	Current []*endpoint.Endpoint
 	// List of desired records
 	Desired []*endpoint.Endpoint
-	// Policy under which the desired changes are calculated
-	Policy Policy
+	// Policies under which the desired changes are calculated
+	Policies []Policy
 	// List of changes necessary to move towards desired state
 	// Populated after calling Calculate()
 	Changes *Changes
@@ -86,8 +86,10 @@ func (p *Plan) Calculate() *Plan {
 		}
 	}
 
-	// Apply policy to list of changes.
-	changes = p.Policy.Apply(changes)
+	// Apply policies to list of changes.
+	for _, pol := range p.Policies {
+		changes = pol.Apply(changes)
+	}
 
 	plan := &Plan{
 		Current: p.Current,

plan/plan_test.go

@@ -47,34 +47,34 @@ func TestCalculate(t *testing.T) {
 	typedV1 := []*endpoint.Endpoint{endpoint.NewEndpoint("foo", "v1", "A")}
 
 	for _, tc := range []struct {
-		policy                               Policy
+		policies                             []Policy
 		current, desired                     []*endpoint.Endpoint
 		create, updateOld, updateNew, delete []*endpoint.Endpoint
 	}{
 		// Nothing exists and nothing desired doesn't change anything.
-		{&SyncPolicy{}, empty, empty, empty, empty, empty, empty},
+		{[]Policy{&SyncPolicy{}}, empty, empty, empty, empty, empty, empty},
 		// More desired than current creates the desired.
-		{&SyncPolicy{}, empty, fooV1, fooV1, empty, empty, empty},
+		{[]Policy{&SyncPolicy{}}, empty, fooV1, fooV1, empty, empty, empty},
 		// Desired equals current doesn't change anything.
-		{&SyncPolicy{}, fooV1, fooV1, empty, empty, empty, empty},
+		{[]Policy{&SyncPolicy{}}, fooV1, fooV1, empty, empty, empty, empty},
 		// Nothing is desired deletes the current.
-		{&SyncPolicy{}, fooV1, empty, empty, empty, empty, fooV1},
+		{[]Policy{&SyncPolicy{}}, fooV1, empty, empty, empty, empty, fooV1},
 		// Current and desired match but Target is different triggers an update.
-		{&SyncPolicy{}, fooV1, fooV2, empty, fooV1, fooV2, empty},
+		{[]Policy{&SyncPolicy{}}, fooV1, fooV2, empty, fooV1, fooV2, empty},
 		// Both exist but are different creates desired and deletes current.
-		{&SyncPolicy{}, fooV1, bar, bar, empty, empty, fooV1},
+		{[]Policy{&SyncPolicy{}}, fooV1, bar, bar, empty, empty, fooV1},
 		// Nothing is desired but policy doesn't allow deletions.
-		{&UpsertOnlyPolicy{}, fooV1, empty, empty, empty, empty, empty},
+		{[]Policy{&UpsertOnlyPolicy{}}, fooV1, empty, empty, empty, empty, empty},
 		// Labels should be inherited
-		{&SyncPolicy{}, labeledV1, noLabels, empty, labeledV1, labeledV2, empty},
+		{[]Policy{&SyncPolicy{}}, labeledV1, noLabels, empty, labeledV1, labeledV2, empty},
 		// RecordType should be inherited
-		{&SyncPolicy{}, typedV1, noType, empty, typedV1, typedV2, empty},
+		{[]Policy{&SyncPolicy{}}, typedV1, noType, empty, typedV1, typedV2, empty},
 	} {
 		// setup plan
 		plan := &Plan{
-			Policy:  tc.policy,
-			Current: tc.current,
-			Desired: tc.desired,
+			Policies: tc.policies,
+			Current:  tc.current,
+			Desired:  tc.desired,
 		}
 		// calculate actions
 		plan = plan.Calculate()
@@ -116,9 +116,9 @@ func ExamplePlan() {
 	// * bar should be updated from v1 to v2
 	// * baz should be created
 	plan := &Plan{
-		Policy:  &SyncPolicy{},
-		Current: []*endpoint.Endpoint{foo, barV1},
-		Desired: []*endpoint.Endpoint{barV2, baz},
+		Policies: []Policy{&SyncPolicy{}},
+		Current:  []*endpoint.Endpoint{foo, barV1},
+		Desired:  []*endpoint.Endpoint{barV2, baz},
 	}
 
 	// calculate actions