Refactor readiness function

lib/backend/constants.go

@@ -4,7 +4,7 @@
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
-//	   http://www.apache.org/licenses/LICENSE-2.0
+//	http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ -14,6 +14,7 @@
 package backend
 
 import (
+	"github.com/uber/kraken/core"
 	"github.com/uber/kraken/utils/memsize"
 
 	"github.com/c2h5oh/datasize"
@@ -25,3 +26,8 @@ const (
 	DefaultConcurrency int               = 10
 	DefaultListMaxKeys int               = 250
 )
+
+var (
+	ReadinessCheckNamespace string = core.NamespaceFixture()
+	ReadinessCheckName      string = core.DigestFixture().Hex()
+)

lib/backend/manager.go

@@ -29,12 +29,10 @@ import (
 var (
 	ErrNamespaceNotFound = errors.New("no matches for namespace")
 )
-const isReadyNamespace = "isReadyNamespace"
-const isReadyName = "38a03d499119bc417b8a6a016f2cb4540b9f9cc0c13e4da42a73867120d3e908"
 
 type backend struct {
-	regexp *regexp.Regexp
-	client Client
+	regexp    *regexp.Regexp
+	client    Client
 	mustReady bool
 }
 
@@ -44,8 +42,8 @@ func newBackend(namespace string, c Client, mustReady bool) (*backend, error) {
 		return nil, fmt.Errorf("regexp: %s", err)
 	}
 	return &backend{
-		regexp: re,
-		client: c,
+		regexp:    re,
+		client:    c,
 		mustReady: mustReady,
 	}, nil
 }
@@ -147,15 +145,15 @@ func (m *Manager) GetClient(namespace string) (Client, error) {
 
 // IsReady returns whether the backends are ready (reachable).
 // A backend must be explicitly configured as required for readiness to be checked.
-func (m *Manager) IsReady() (bool, error) {
+func (m *Manager) CheckReadiness() error {
 	for _, b := range m.backends {
 		if !b.mustReady {
 			continue
 		}
-		_, err := b.client.Stat(isReadyNamespace, isReadyName)
+		_, err := b.client.Stat(ReadinessCheckNamespace, ReadinessCheckName)
 		if err != nil && err != backenderrors.ErrBlobNotFound {
-			return false, fmt.Errorf("backend for namespace %s not ready: %s", b.regexp.String(), err)
+			return fmt.Errorf("backend for namespace '%s' not ready: %s", b.regexp.String(), err)
 		}
 	}
-	return true, nil
+	return nil
 }

lib/backend/manager_test.go

@@ -19,6 +19,7 @@ import (
 
 	"github.com/uber-go/tally"
 	"github.com/uber/kraken/core"
+	"github.com/uber/kraken/lib/backend"
 	. "github.com/uber/kraken/lib/backend"
 	"github.com/uber/kraken/lib/backend/backenderrors"
 	"github.com/uber/kraken/lib/backend/namepath"
@@ -159,10 +160,7 @@ func TestManagerBandwidth(t *testing.T) {
 	checkBandwidth(5, 25)
 }
 
-func TestManagerIsReady(t *testing.T) {
-	const isReadyNamespace = "isReadyNamespace"
-	const isReadyName = "38a03d499119bc417b8a6a016f2cb4540b9f9cc0c13e4da42a73867120d3e908"
-
+func TestManagerCheckReadiness(t *testing.T) {
 	n1 := "foo/*"
 	n2 := "bar/*"
 
@@ -191,7 +189,7 @@ func TestManagerIsReady(t *testing.T) {
 			mockStat1Err: nil,
 			mockStat2Err: errors.New("network error"),
 			expectedRes:  false,
-			expectedErr:  errors.New("backend for namespace bar/* not ready: network error"),
+			expectedErr:  errors.New("backend for namespace 'bar/*' not ready: network error"),
 		},
 		{
 			name:         "second required, only first fails",
@@ -224,14 +222,13 @@ func TestManagerIsReady(t *testing.T) {
 				mockStat2 = nil
 			}
 
-			c1.EXPECT().Stat(isReadyNamespace, isReadyName).Return(mockStat1, tc.mockStat1Err).AnyTimes()
-			c2.EXPECT().Stat(isReadyNamespace, isReadyName).Return(mockStat2, tc.mockStat2Err).AnyTimes()
+			c1.EXPECT().Stat(backend.ReadinessCheckNamespace, backend.ReadinessCheckName).Return(mockStat1, tc.mockStat1Err).AnyTimes()
+			c2.EXPECT().Stat(backend.ReadinessCheckNamespace, backend.ReadinessCheckName).Return(mockStat2, tc.mockStat2Err).AnyTimes()
 
 			require.NoError(m.Register(n1, c1, tc.mustReady1))
 			require.NoError(m.Register(n2, c2, tc.mustReady2))
 
-			res, err := m.IsReady()
-			require.Equal(tc.expectedRes, res)
+			err := m.CheckReadiness()
 			if tc.expectedErr == nil {
 				require.NoError(err)
 			} else {