[NET-7265] Panic when passing an incorrect type to the data fetcher for gatewayproxy (#20238)

* panic when passing an incorrect type to the data fetcher

* Add assertions for sidecarproxy datafetcher as well

* rename assertion function

* Add in comments to ensure devs know about potential panics for using
invalid types

* fix method call

internal/mesh/internal/controllers/gatewayproxy/controller.go

@@ -120,7 +120,7 @@ func (r *reconciler) Reconcile(ctx context.Context, rt controller.Runtime, req c
 	}
 
 	var exportedServices []*pbmulticluster.ComputedExportedService
-	dec, err := dataFetcher.FetchExportedServices(ctx, exportedServicesID)
+	dec, err := dataFetcher.FetchComputedExportedServices(ctx, exportedServicesID)
 	if err != nil {
 		rt.Logger.Error("error reading the associated exported services", "error", err)
 	} else if dec == nil {

internal/mesh/internal/controllers/gatewayproxy/fetcher/data_fetcher.go

@@ -5,6 +5,7 @@ package fetcher
 
 import (
 	"context"
+	"fmt"
 
 	"github.com/hashicorp/consul/internal/mesh/internal/controllers/sidecarproxy/cache"
 	"github.com/hashicorp/consul/internal/mesh/internal/types"
@@ -13,6 +14,7 @@ import (
 	pbmesh "github.com/hashicorp/consul/proto-public/pbmesh/v2beta1"
 	pbmulticluster "github.com/hashicorp/consul/proto-public/pbmulticluster/v2beta1"
 	"github.com/hashicorp/consul/proto-public/pbresource"
+	"google.golang.org/protobuf/proto"
 )
 
 type Fetcher struct {
@@ -27,7 +29,11 @@ func New(client pbresource.ResourceServiceClient, cache *cache.Cache) *Fetcher {
 	}
 }
 
+// FetchMeshGateway fetches a service resource from the resource service.
+// This will panic if the type field in the ID argument is not a MeshGateway type.
 func (f *Fetcher) FetchMeshGateway(ctx context.Context, id *pbresource.ID) (*types.DecodedMeshGateway, error) {
+	assertResourceType(pbmesh.MeshGatewayType, id.Type)
+
 	dec, err := resource.GetDecodedResource[*pbmesh.MeshGateway](ctx, f.client, id)
 	if err != nil {
 		return nil, err
@@ -38,7 +44,11 @@ func (f *Fetcher) FetchMeshGateway(ctx context.Context, id *pbresource.ID) (*typ
 	return dec, nil
 }
 
+// FetchProxyStateTemplate fetches a service resource from the resource service.
+// This will panic if the type field in the ID argument is not a ProxyStateTemplate type.
 func (f *Fetcher) FetchProxyStateTemplate(ctx context.Context, id *pbresource.ID) (*types.DecodedProxyStateTemplate, error) {
+	assertResourceType(pbmesh.ProxyStateTemplateType, id.Type)
+
 	dec, err := resource.GetDecodedResource[*pbmesh.ProxyStateTemplate](ctx, f.client, id)
 	if err != nil {
 		return nil, err
@@ -49,7 +59,11 @@ func (f *Fetcher) FetchProxyStateTemplate(ctx context.Context, id *pbresource.ID
 	return dec, nil
 }
 
+// FetchWorkload fetches a service resource from the resource service.
+// This will panic if the type field in the ID argument is not a Workload type.
 func (f *Fetcher) FetchWorkload(ctx context.Context, id *pbresource.ID) (*types.DecodedWorkload, error) {
+	assertResourceType(pbcatalog.WorkloadType, id.Type)
+
 	dec, err := resource.GetDecodedResource[*pbcatalog.Workload](ctx, f.client, id)
 	if err != nil {
 		return nil, err
@@ -60,7 +74,11 @@ func (f *Fetcher) FetchWorkload(ctx context.Context, id *pbresource.ID) (*types.
 	return dec, nil
 }
 
-func (f *Fetcher) FetchExportedServices(ctx context.Context, id *pbresource.ID) (*types.DecodedComputedExportedServices, error) {
+// FetchComputedExportedServices fetches a service resource from the resource service.
+// This will panic if the type field in the ID argument is not a ComputedExportedServices type.
+func (f *Fetcher) FetchComputedExportedServices(ctx context.Context, id *pbresource.ID) (*types.DecodedComputedExportedServices, error) {
+	assertResourceType(pbmulticluster.ComputedExportedServicesType, id.Type)
+
 	dec, err := resource.GetDecodedResource[*pbmulticluster.ComputedExportedServices](ctx, f.client, id)
 	if err != nil {
 		return nil, err
@@ -71,7 +89,11 @@ func (f *Fetcher) FetchExportedServices(ctx context.Context, id *pbresource.ID)
 	return dec, nil
 }
 
+// FetchService fetches a service resource from the resource service.
+// This will panic if the type field in the ID argument is not a Service type.
 func (f *Fetcher) FetchService(ctx context.Context, id *pbresource.ID) (*types.DecodedService, error) {
+	assertResourceType(pbcatalog.ServiceType, id.Type)
+
 	dec, err := resource.GetDecodedResource[*pbcatalog.Service](ctx, f.client, id)
 	if err != nil {
 		return nil, err
@@ -81,3 +103,11 @@ func (f *Fetcher) FetchService(ctx context.Context, id *pbresource.ID) (*types.D
 
 	return dec, nil
 }
+
+// this is a helper function to ensure that the resource type we are querying for is the type we expect
+func assertResourceType(expected, actual *pbresource.Type) {
+	if !proto.Equal(expected, actual) {
+		// this is always a programmer error so safe to panic
+		panic(fmt.Sprintf("expected a query for a type of %q, you provided a type of %q", expected, actual))
+	}
+}

internal/mesh/internal/controllers/gatewayproxy/fetcher/data_fetcher_test.go

@@ -124,6 +124,15 @@ func (suite *dataFetcherSuite) TestFetcher_FetchMeshGateway() {
 			require.NoError(t, err)
 			require.NotNil(t, gtw)
 		})
+
+		testutil.RunStep(suite.T(), "incorrect type is passed", func(t *testing.T) {
+			incorrectID := resourcetest.Resource(pbcatalog.ServiceType, "api-1").ID()
+			defer func() {
+				err := recover()
+				require.NotNil(t, err)
+			}()
+			f.FetchMeshGateway(suite.ctx, incorrectID)
+		})
 	})
 }
 
@@ -148,6 +157,15 @@ func (suite *dataFetcherSuite) TestFetcher_FetchProxyStateTemplate() {
 			require.NoError(t, err)
 			require.NotNil(t, tmpl)
 		})
+
+		testutil.RunStep(suite.T(), "incorrect type is passed", func(t *testing.T) {
+			incorrectID := resourcetest.Resource(pbcatalog.ServiceType, "api-1").ID()
+			defer func() {
+				err := recover()
+				require.NotNil(t, err)
+			}()
+			f.FetchProxyStateTemplate(suite.ctx, incorrectID)
+		})
 	})
 }
 
@@ -186,13 +204,13 @@ func (suite *dataFetcherSuite) TestFetcher_FetchExportedServices() {
 
 		testutil.RunStep(suite.T(), "exported services do not exist", func(t *testing.T) {
 			nonExistantID := resourcetest.Resource(pbmulticluster.ComputedExportedServicesType, "not-found").ID()
-			svcs, err := f.FetchExportedServices(suite.ctx, nonExistantID)
+			svcs, err := f.FetchComputedExportedServices(suite.ctx, nonExistantID)
 			require.NoError(t, err)
 			require.Nil(t, svcs)
 		})
 
 		testutil.RunStep(suite.T(), "workload exists", func(t *testing.T) {
-			svcs, err := f.FetchExportedServices(suite.ctx, suite.exportedServices.Id)
+			svcs, err := f.FetchComputedExportedServices(suite.ctx, suite.exportedServices.Id)
 			require.NoError(t, err)
 			require.NotNil(t, svcs)
 		})
@@ -220,6 +238,15 @@ func (suite *dataFetcherSuite) TestFetcher_FetchService() {
 			require.NoError(t, err)
 			require.NotNil(t, svc)
 		})
+
+		testutil.RunStep(suite.T(), "incorrect type is passed", func(t *testing.T) {
+			incorrectID := resourcetest.Resource(pbmesh.ProxyStateTemplateType, "api-1").ID()
+			defer func() {
+				err := recover()
+				require.NotNil(t, err)
+			}()
+			f.FetchService(suite.ctx, incorrectID)
+		})
 	})
 }
 

internal/mesh/internal/controllers/sidecarproxy/controller.go

@@ -200,7 +200,7 @@ func (r *reconciler) Reconcile(ctx context.Context, rt controller.Runtime, req c
 		BuildLocalApp(workloadDataWithInheritedPorts, ctp)
 
 	// Get all destinationsData.
-	destinationsData, err := dataFetcher.FetchExplicitDestinationsData(ctx, req.ID)
+	destinationsData, err := dataFetcher.FetchComputedExplicitDestinationsData(ctx, req.ID)
 	if err != nil {
 		rt.Logger.Error("error fetching explicit destinations for this proxy", "error", err)
 		return err
@@ -253,7 +253,6 @@ func (r *reconciler) workloadPortProtocolsFromService(
 	workload *types.DecodedWorkload,
 	logger hclog.Logger,
 ) (map[string]*pbcatalog.WorkloadPort, error) {
-
 	// Fetch all services for this workload.
 	serviceIDs := r.cache.ServicesForWorkload(workload.GetResource().GetId())
 

internal/mesh/internal/controllers/sidecarproxy/fetcher/data_fetcher.go

@@ -33,7 +33,10 @@ func New(client pbresource.ResourceServiceClient, cache *cache.Cache) *Fetcher {
 	}
 }
 
+// FetchWorkload fetches a service resource from the resource service.
+// This will panic if the type field in the ID argument is not a Workload type.
 func (f *Fetcher) FetchWorkload(ctx context.Context, id *pbresource.ID) (*types.DecodedWorkload, error) {
+	assertResourceType(pbcatalog.WorkloadType, id.Type)
 	dec, err := resource.GetDecodedResource[*pbcatalog.Workload](ctx, f.client, id)
 	if err != nil {
 		return nil, err
@@ -48,27 +51,45 @@ func (f *Fetcher) FetchWorkload(ctx context.Context, id *pbresource.ID) (*types.
 	return dec, err
 }
 
+// FetchProxyStateTemplate fetches a service resource from the resource service.
+// This will panic if the type field in the ID argument is not a ProxyStateTemplate type.
 func (f *Fetcher) FetchProxyStateTemplate(ctx context.Context, id *pbresource.ID) (*types.DecodedProxyStateTemplate, error) {
+	assertResourceType(pbmesh.ProxyStateTemplateType, id.Type)
 	return resource.GetDecodedResource[*pbmesh.ProxyStateTemplate](ctx, f.client, id)
 }
 
+// FetchComputedTrafficPermissions fetches a service resource from the resource service.
+// This will panic if the type field in the ID argument is not a ComputedTrafficPermissons type.
 func (f *Fetcher) FetchComputedTrafficPermissions(ctx context.Context, id *pbresource.ID) (*types.DecodedComputedTrafficPermissions, error) {
+	assertResourceType(pbauth.ComputedTrafficPermissionsType, id.Type)
 	return resource.GetDecodedResource[*pbauth.ComputedTrafficPermissions](ctx, f.client, id)
 }
 
+// FetchServiceEndpoints fetches a service resource from the resource service.
+// This will panic if the type field in the ID argument is not a ServiceEndpoints type.
 func (f *Fetcher) FetchServiceEndpoints(ctx context.Context, id *pbresource.ID) (*types.DecodedServiceEndpoints, error) {
+	assertResourceType(pbcatalog.ServiceEndpointsType, id.Type)
 	return resource.GetDecodedResource[*pbcatalog.ServiceEndpoints](ctx, f.client, id)
 }
 
+// FetchService fetches a service resource from the resource service.
+// This will panic if the type field in the ID argument is not a Service type.
 func (f *Fetcher) FetchService(ctx context.Context, id *pbresource.ID) (*types.DecodedService, error) {
+	assertResourceType(pbcatalog.ServiceType, id.Type)
 	return resource.GetDecodedResource[*pbcatalog.Service](ctx, f.client, id)
 }
 
+// FetchDestinations fetches a service resource from the resource service.
+// This will panic if the type field in the ID argument is not a Destinations type.
 func (f *Fetcher) FetchDestinations(ctx context.Context, id *pbresource.ID) (*types.DecodedDestinations, error) {
+	assertResourceType(pbmesh.DestinationsType, id.Type)
 	return resource.GetDecodedResource[*pbmesh.Destinations](ctx, f.client, id)
 }
 
+// FetchComputedRoutes fetches a service resource from the resource service.
+// This will panic if the type field in the ID argument is not a ComputedRoutes type.
 func (f *Fetcher) FetchComputedRoutes(ctx context.Context, id *pbresource.ID) (*types.DecodedComputedRoutes, error) {
+	assertResourceType(pbmesh.ComputedRoutesType, id.Type)
 	if !types.IsComputedRoutesType(id.Type) {
 		return nil, fmt.Errorf("id must be a ComputedRoutes type")
 	}
@@ -83,11 +104,10 @@ func (f *Fetcher) FetchComputedRoutes(ctx context.Context, id *pbresource.ID) (*
 	return dec, err
 }
 
-func (f *Fetcher) FetchExplicitDestinationsData(
+func (f *Fetcher) FetchComputedExplicitDestinationsData(
 	ctx context.Context,
 	proxyID *pbresource.ID,
 ) ([]*intermediateTypes.Destination, error) {
-
 	var destinations []*intermediateTypes.Destination
 
 	// Fetch computed explicit destinations first.
@@ -107,9 +127,7 @@ func (f *Fetcher) FetchExplicitDestinationsData(
 	for _, dest := range cd.GetData().GetDestinations() {
 		d := &intermediateTypes.Destination{}
 
-		var (
+		serviceID := resource.IDFromReference(dest.DestinationRef)
-			serviceID = resource.IDFromReference(dest.DestinationRef)
-		)
 
 		// Fetch Service
 		svc, err := f.FetchService(ctx, serviceID)
@@ -372,3 +390,10 @@ func isPartOfService(workloadID *pbresource.ID, svc *types.DecodedService) bool
 	}
 	return false
 }
+
+func assertResourceType(expected, actual *pbresource.Type) {
+	if !proto.Equal(expected, actual) {
+		// this is always a programmer error so safe to panic
+		panic(fmt.Sprintf("expected a query for a type of %q, you provided a type of %q", expected, actual))
+	}
+}

internal/mesh/internal/controllers/sidecarproxy/fetcher/data_fetcher_test.go

@@ -227,9 +227,7 @@ func (suite *dataFetcherSuite) TestFetcher_FetchExplicitDestinationsData() {
 	suite.runTestCaseWithTenancies(func(tenancy *pbresource.Tenancy) {
 		c := cache.New()
 
-		var (
+		api1ServiceRef := resource.Reference(suite.api1Service.Id, "")
-			api1ServiceRef = resource.Reference(suite.api1Service.Id, "")
-		)
 
 		f := Fetcher{
 			cache:  c,
@@ -252,7 +250,7 @@ func (suite *dataFetcherSuite) TestFetcher_FetchExplicitDestinationsData() {
 			c.TrackComputedDestinations(resourcetest.MustDecode[*pbmesh.ComputedExplicitDestinations](t, compDest))
 
 			// We will try to fetch explicit destinations for a proxy that doesn't have one.
-			destinations, err := f.FetchExplicitDestinationsData(suite.ctx, suite.webProxy.Id)
+			destinations, err := f.FetchComputedExplicitDestinationsData(suite.ctx, suite.webProxy.Id)
 			require.NoError(t, err)
 			require.Nil(t, destinations)
 
@@ -277,7 +275,7 @@ func (suite *dataFetcherSuite) TestFetcher_FetchExplicitDestinationsData() {
 				WithTenancy(tenancy).
 				Write(t, suite.client)
 
-			destinations, err := f.FetchExplicitDestinationsData(suite.ctx, suite.webProxy.Id)
+			destinations, err := f.FetchComputedExplicitDestinationsData(suite.ctx, suite.webProxy.Id)
 			require.NoError(t, err)
 			require.Nil(t, destinations)
 			cachedCompDestIDs := c.ComputedDestinationsByService(resource.IDFromReference(notFoundServiceRef))
@@ -307,7 +305,7 @@ func (suite *dataFetcherSuite) TestFetcher_FetchExplicitDestinationsData() {
 				WithTenancy(tenancy).
 				Write(t, suite.client)
 
-			destinations, err := f.FetchExplicitDestinationsData(suite.ctx, suite.webProxy.Id)
+			destinations, err := f.FetchComputedExplicitDestinationsData(suite.ctx, suite.webProxy.Id)
 			require.NoError(t, err)
 			require.Nil(t, destinations)
 			cachedCompDestIDs := c.ComputedDestinationsByService(resource.IDFromReference(api1ServiceRef))
@@ -337,7 +335,7 @@ func (suite *dataFetcherSuite) TestFetcher_FetchExplicitDestinationsData() {
 				WithTenancy(tenancy).
 				Write(t, suite.client)
 
-			destinations, err := f.FetchExplicitDestinationsData(suite.ctx, suite.webProxy.Id)
+			destinations, err := f.FetchComputedExplicitDestinationsData(suite.ctx, suite.webProxy.Id)
 			require.NoError(t, err)
 			require.Nil(t, destinations)
 			cachedCompDestIDs := c.ComputedDestinationsByService(resource.IDFromReference(api1ServiceRef))
@@ -369,7 +367,7 @@ func (suite *dataFetcherSuite) TestFetcher_FetchExplicitDestinationsData() {
 				WithTenancy(tenancy).
 				Write(t, suite.client)
 
-			destinations, err := f.FetchExplicitDestinationsData(suite.ctx, suite.webProxy.Id)
+			destinations, err := f.FetchComputedExplicitDestinationsData(suite.ctx, suite.webProxy.Id)
 			require.NoError(t, err)
 			require.Empty(t, destinations)
 
@@ -402,7 +400,7 @@ func (suite *dataFetcherSuite) TestFetcher_FetchExplicitDestinationsData() {
 			require.NotNil(suite.T(), api1ComputedRoutes)
 
 			// This destination points to TCP, but the computed routes is stale and only knows about HTTP.
-			destinations, err := f.FetchExplicitDestinationsData(suite.ctx, suite.webProxy.Id)
+			destinations, err := f.FetchComputedExplicitDestinationsData(suite.ctx, suite.webProxy.Id)
 			require.NoError(t, err)
 
 			// Check that we didn't return any destinations.
@@ -483,7 +481,7 @@ func (suite *dataFetcherSuite) TestFetcher_FetchExplicitDestinationsData() {
 				},
 			}
 
-			actualDestinations, err := f.FetchExplicitDestinationsData(suite.ctx, suite.webProxy.Id)
+			actualDestinations, err := f.FetchComputedExplicitDestinationsData(suite.ctx, suite.webProxy.Id)
 			require.NoError(t, err)
 
 			// Check that we've computed expanded destinations correctly.