catalog: improve the bound workload identity encoding on services

internal/catalog/exports.go

@@ -63,6 +63,16 @@ func SimplifyFailoverPolicy(svc *pbcatalog.Service, failover *pbcatalog.Failover
 	return types.SimplifyFailoverPolicy(svc, failover)
 }
 
+// GetBoundIdentities returns the unique list of workload identity references
+// encoded into a data-bearing status condition on a Service resource by the
+// endpoints controller.
+//
+// This allows a controller to skip watching ServiceEndpoints (which is
+// expensive) to discover this data.
+func GetBoundIdentities(res *pbresource.Resource) []string {
+	return endpoints.GetBoundIdentities(res)
+}
+
 // ValidateLocalServiceRefNoSection ensures the following:
 //
 // - ref is non-nil

internal/catalog/internal/controllers/endpoints/bound.go

@@ -0,0 +1,46 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: BUSL-1.1
+
+package endpoints
+
+import (
+	"sort"
+	"strings"
+
+	"github.com/hashicorp/consul/proto-public/pbresource"
+)
+
+// GetBoundIdentities returns the unique list of workload identity references
+// encoded into a data-bearing status condition on a Service resource by the
+// endpoints controller.
+//
+// This allows a controller to skip watching ServiceEndpoints (which is
+// expensive) to discover this data.
+func GetBoundIdentities(res *pbresource.Resource) []string {
+	if res.GetStatus() == nil {
+		return nil
+	}
+
+	status, ok := res.GetStatus()[ControllerID]
+	if !ok {
+		return nil
+	}
+
+	var encoded string
+	for _, cond := range status.GetConditions() {
+		if cond.GetType() == StatusConditionBoundIdentities && cond.GetState() == pbresource.Condition_STATE_TRUE {
+			encoded = cond.GetMessage()
+			break
+		}
+	}
+	if encoded == "" {
+		return nil
+	}
+
+	identities := strings.Split(encoded, ",")
+
+	// Ensure determinstic sort so we don't get into infinite-reconcile
+	sort.Strings(identities)
+
+	return identities
+}

internal/catalog/internal/controllers/endpoints/bound_test.go

@@ -0,0 +1,63 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: BUSL-1.1
+
+package endpoints_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/hashicorp/consul/internal/catalog/internal/controllers/endpoints"
+	"github.com/hashicorp/consul/internal/resource"
+	"github.com/hashicorp/consul/internal/resource/demo"
+	rtest "github.com/hashicorp/consul/internal/resource/resourcetest"
+	"github.com/hashicorp/consul/proto-public/pbresource"
+	pbdemo "github.com/hashicorp/consul/proto/private/pbdemo/v2"
+)
+
+func TestGetBoundIdentities(t *testing.T) {
+	tenancy := resource.DefaultNamespacedTenancy()
+
+	build := func(conds ...*pbresource.Condition) *pbresource.Resource {
+		b := rtest.Resource(demo.TypeV2Artist, "artist").
+			WithTenancy(tenancy).
+			WithData(t, &pbdemo.Artist{Name: "very arty"})
+		if len(conds) > 0 {
+			b.WithStatus(endpoints.ControllerID, &pbresource.Status{
+				Conditions: conds,
+			})
+		}
+		return b.Build()
+	}
+
+	run := endpoints.GetBoundIdentities
+
+	require.Empty(t, run(build(nil)))
+	require.Empty(t, run(build(&pbresource.Condition{
+		Type:    endpoints.StatusConditionBoundIdentities,
+		State:   pbresource.Condition_STATE_TRUE,
+		Message: "",
+	})))
+	require.Equal(t, []string{"foo"}, run(build(&pbresource.Condition{
+		Type:    endpoints.StatusConditionBoundIdentities,
+		State:   pbresource.Condition_STATE_TRUE,
+		Message: "foo",
+	})))
+	require.Empty(t, run(build(&pbresource.Condition{
+		Type:    endpoints.StatusConditionBoundIdentities,
+		State:   pbresource.Condition_STATE_FALSE,
+		Message: "foo",
+	})))
+	require.Equal(t, []string{"bar", "foo"}, run(build(&pbresource.Condition{
+		Type:    endpoints.StatusConditionBoundIdentities,
+		State:   pbresource.Condition_STATE_TRUE,
+		Message: "bar,foo", // proper order
+	})))
+	require.Equal(t, []string{"bar", "foo"}, run(build(&pbresource.Condition{
+		Type:    endpoints.StatusConditionBoundIdentities,
+		State:   pbresource.Condition_STATE_TRUE,
+		Message: "foo,bar", // incorrect order gets fixed
+	})))
+
+}

internal/catalog/internal/controllers/endpoints/status.go

@@ -4,7 +4,7 @@
 package endpoints
 
 import (
-	"fmt"
+	"sort"
 	"strings"
 
 	"github.com/hashicorp/consul/proto-public/pbresource"
@@ -24,9 +24,6 @@ const (
 
 	StatusReasonWorkloadIdentitiesFound   = "WorkloadIdentitiesFound"
 	StatusReasonNoWorkloadIdentitiesFound = "NoWorkloadIdentitiesFound"
-
-	identitiesFoundMessageFormat     = "Found workload identities associated with this service: %q."
-	identitiesNotFoundChangedMessage = "No associated workload identities found."
 )
 
 var (
@@ -48,15 +45,17 @@ var (
 		Type:    StatusConditionBoundIdentities,
 		State:   pbresource.Condition_STATE_FALSE,
 		Reason:  StatusReasonNoWorkloadIdentitiesFound,
-		Message: identitiesNotFoundChangedMessage,
+		Message: "",
 	}
 )
 
 func ConditionIdentitiesFound(identities []string) *pbresource.Condition {
+	sort.Strings(identities)
+
 	return &pbresource.Condition{
 		Type:    StatusConditionBoundIdentities,
 		State:   pbresource.Condition_STATE_TRUE,
 		Reason:  StatusReasonWorkloadIdentitiesFound,
-		Message: fmt.Sprintf(identitiesFoundMessageFormat, strings.Join(identities, ",")),
+		Message: strings.Join(identities, ","),
 	}
 }