[Graphql] Add ability to query for backend (#4844)

Signed-off-by: Melissa Page <[email protected]>

backend/apid/graphql/backendEntity.go

@@ -0,0 +1,13 @@
+package graphql
+
+import (
+	corev2 "github.com/sensu/sensu-go/api/core/v2"
+	"github.com/sensu/sensu-go/graphql"
+)
+
+type backendEntityImpl struct{}
+
+func (b *backendEntityImpl) Meta(p graphql.ResolveParams) (interface{}, error) {
+	v := p.Source.(interface{ GetMetadata() *corev2.ObjectMeta })
+	return v.GetMetadata(), nil
+}

backend/apid/graphql/query.go

@@ -37,6 +37,11 @@ type queryImpl struct {
 	svc          ServiceConfig
 }
 
+// Responder implements response to a request for the 'responder' field.
+func (r *queryImpl) Responder(p graphql.ResolveParams) (interface{}, error) {
+	return r.svc.GetBackendEntity()
+}
+
 // Viewer implements response to request for 'viewer' field.
 func (r *queryImpl) Viewer(p graphql.ResolveParams) (interface{}, error) {
 	return struct{}{}, nil

backend/apid/graphql/query_test.go

@@ -8,6 +8,7 @@ import (
 
 	dto "github.com/prometheus/client_model/go"
 	corev2 "github.com/sensu/sensu-go/api/core/v2"
+	corev3 "github.com/sensu/sensu-go/api/core/v3"
 	"github.com/sensu/sensu-go/backend/apid/graphql/schema"
 	"github.com/sensu/sensu-go/graphql"
 	"github.com/stretchr/testify/assert"
@@ -231,3 +232,49 @@ func Test_queryImpl_Metrics(t *testing.T) {
 		})
 	}
 }
+
+func Test_queryImpl_Responder(t *testing.T) {
+	tests := []struct {
+		name       string
+		gatherResp corev3.Resource
+		gatherErr  error
+		params     graphql.ResolveParams
+		want       interface{}
+		wantErr    bool
+	}{
+		{
+			name:       "returns backend entity",
+			gatherResp: corev3.FixtureEntityConfig("backend"),
+			gatherErr:  nil,
+			want:       corev3.FixtureEntityConfig("backend"),
+			wantErr:    false,
+		},
+		{
+			name:       "returns an error",
+			gatherResp: corev3.FixtureEntityConfig("backend"),
+			gatherErr:  errors.New("Error"),
+			want:       corev3.FixtureEntityConfig("backend"),
+			wantErr:    true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			mock := func() (interface{ GetMetadata() *corev2.ObjectMeta }, error) {
+				return tt.gatherResp, tt.gatherErr
+			}
+			r := &queryImpl{
+				svc: ServiceConfig{
+					GetBackendEntity: mock,
+				},
+			}
+			got, err := r.Responder(tt.params)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("queryImpl.Responder() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("queryImpl.Responder() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

backend/apid/graphql/schema/entity.graphql

@@ -134,6 +134,16 @@ type Process {
   memoryPercent: Float!
 }
 
+"""
+BackendEntity contains information about a particular backend.
+"""
+type BackendEntity {
+  meta: ObjectMeta
+  # TODO: implement these
+  # config: CoreV3EntityConfig
+  # state: CoreV3EntityState
+}
+
 """
 Network contains information about the system network interfaces
 that the Agent process is running on, used for additional Entity

backend/apid/graphql/schema/query.graphql

@@ -2,6 +2,11 @@
 The query root of Sensu's GraphQL interface.
 """
 type Query {
+  """
+  Responder is what backend responded to the query.
+  """
+  responder: BackendEntity
+
   """
   Current viewer.
   """

backend/apid/graphql/service.go

@@ -3,6 +3,7 @@ package graphql
 import (
 	"context"
 
+	corev2 "github.com/sensu/sensu-go/api/core/v2"
 	"github.com/sensu/sensu-go/backend/apid/graphql/relay"
 	"github.com/sensu/sensu-go/backend/apid/graphql/schema"
 	"github.com/sensu/sensu-go/cli/client"
@@ -28,6 +29,7 @@ type ServiceConfig struct {
 	EntityClient       EntityClient
 	EventClient        EventClient
 	EventFilterClient  EventFilterClient
+	GetBackendEntity   func() (interface{ GetMetadata() *corev2.ObjectMeta }, error)
 	HandlerClient      HandlerClient
 	HealthController   EtcdHealthController
 	MutatorClient      MutatorClient
@@ -66,6 +68,7 @@ func NewService(cfg ServiceConfig) (*Service, error) {
 
 	// Register types
 	schema.RegisterAsset(svc, &assetImpl{})
+	schema.RegisterBackendEntity(svc, &backendEntityImpl{})
 	schema.RegisterCoreV2AssetBuild(svc, &schema.CoreV2AssetBuildAliases{})
 	schema.RegisterCoreV2Pipeline(svc, &corev2PipelineImpl{})
 	schema.RegisterCoreV2PipelineExtensionOverrides(svc, &corev2PipelineImpl{})

backend/backend.go

@@ -582,6 +582,9 @@ func Initialize(ctx context.Context, config *Config) (*Backend, error) {
 		EntityClient:      api.NewEntityClient(b.Store, b.StoreV2, b.Store, auth),
 		EventClient:       api.NewEventClient(b.Store, auth, bus),
 		EventFilterClient: api.NewEventFilterClient(b.Store, auth),
+		GetBackendEntity: func() (interface{ GetMetadata() *corev2.ObjectMeta }, error) {
+			return &CoreV3MetaAdapter{In: b.getBackendEntity(config)}, nil
+		},
 		HandlerClient:     api.NewHandlerClient(b.Store, auth),
 		HealthController:  actions.NewHealthController(b.Store, b.Client.Cluster, etcdClientTLSConfig),
 		MutatorClient:     api.NewMutatorClient(b.Store, auth),
@@ -968,3 +971,14 @@ func getSystemInfo() corev2.System {
 	}
 	return info
 }
+
+// CoreV3MetaAdapter adapts corev2 meta to corev3
+type CoreV3MetaAdapter struct {
+	In corev2.Resource
+}
+
+// GetMetadata implements the corev3 resource metadata field
+func (a *CoreV3MetaAdapter) GetMetadata() *corev2.ObjectMeta {
+	v := a.In.GetObjectMeta()
+	return &v
+}