Abstract the error handling for the storage layer to eliminate the

direct etcd dependency.

.gitignore

@@ -13,6 +13,9 @@
 .idea/
 *.iml
 
+# Vscode files
+.vscode/**
+
 # This is where the result of the go build goes
 /output/**
 /output

pkg/api/errors/etcd/etcd.go

@@ -18,68 +18,68 @@ package etcd
 
 import (
 	"k8s.io/kubernetes/pkg/api/errors"
-	etcdutil "k8s.io/kubernetes/pkg/storage/etcd/util"
+	"k8s.io/kubernetes/pkg/storage"
 )
 
-// InterpretListError converts a generic etcd error on a retrieval
+// InterpretListError converts a generic error on a retrieval
 // operation into the appropriate API error.
 func InterpretListError(err error, kind string) error {
 	switch {
-	case etcdutil.IsEtcdNotFound(err):
+	case storage.IsNotFound(err):
 		return errors.NewNotFound(kind, "")
-	case etcdutil.IsEtcdUnreachable(err):
+	case storage.IsUnreachable(err):
 		return errors.NewServerTimeout(kind, "list", 2) // TODO: make configurable or handled at a higher level
 	default:
 		return err
 	}
 }
 
-// InterpretGetError converts a generic etcd error on a retrieval
+// InterpretGetError converts a generic error on a retrieval
 // operation into the appropriate API error.
 func InterpretGetError(err error, kind, name string) error {
 	switch {
-	case etcdutil.IsEtcdNotFound(err):
+	case storage.IsNotFound(err):
 		return errors.NewNotFound(kind, name)
-	case etcdutil.IsEtcdUnreachable(err):
+	case storage.IsUnreachable(err):
 		return errors.NewServerTimeout(kind, "get", 2) // TODO: make configurable or handled at a higher level
 	default:
 		return err
 	}
 }
 
-// InterpretCreateError converts a generic etcd error on a create
+// InterpretCreateError converts a generic error on a create
 // operation into the appropriate API error.
 func InterpretCreateError(err error, kind, name string) error {
 	switch {
-	case etcdutil.IsEtcdNodeExist(err):
+	case storage.IsNodeExist(err):
 		return errors.NewAlreadyExists(kind, name)
-	case etcdutil.IsEtcdUnreachable(err):
+	case storage.IsUnreachable(err):
 		return errors.NewServerTimeout(kind, "create", 2) // TODO: make configurable or handled at a higher level
 	default:
 		return err
 	}
 }
 
-// InterpretUpdateError converts a generic etcd error on a update
+// InterpretUpdateError converts a generic error on a update
 // operation into the appropriate API error.
 func InterpretUpdateError(err error, kind, name string) error {
 	switch {
-	case etcdutil.IsEtcdTestFailed(err), etcdutil.IsEtcdNodeExist(err):
+	case storage.IsTestFailed(err), storage.IsNodeExist(err):
 		return errors.NewConflict(kind, name, err)
-	case etcdutil.IsEtcdUnreachable(err):
+	case storage.IsUnreachable(err):
 		return errors.NewServerTimeout(kind, "update", 2) // TODO: make configurable or handled at a higher level
 	default:
 		return err
 	}
 }
 
-// InterpretDeleteError converts a generic etcd error on a delete
+// InterpretDeleteError converts a generic error on a delete
 // operation into the appropriate API error.
 func InterpretDeleteError(err error, kind, name string) error {
 	switch {
-	case etcdutil.IsEtcdNotFound(err):
+	case storage.IsNotFound(err):
 		return errors.NewNotFound(kind, name)
-	case etcdutil.IsEtcdUnreachable(err):
+	case storage.IsUnreachable(err):
 		return errors.NewServerTimeout(kind, "delete", 2) // TODO: make configurable or handled at a higher level
 	default:
 		return err

pkg/apiserver/errors.go

@@ -21,7 +21,7 @@ import (
 	"net/http"
 
 	"k8s.io/kubernetes/pkg/api/unversioned"
-	etcdutil "k8s.io/kubernetes/pkg/storage/etcd/util"
+	"k8s.io/kubernetes/pkg/storage"
 	"k8s.io/kubernetes/pkg/util"
 )
 
@@ -52,7 +52,7 @@ func errToAPIStatus(err error) *unversioned.Status {
 		status := http.StatusInternalServerError
 		switch {
 		//TODO: replace me with NewConflictErr
-		case etcdutil.IsEtcdTestFailed(err):
+		case storage.IsTestFailed(err):
 			status = http.StatusConflict
 		}
 		// Log errors that were not converted to an error status

pkg/master/master.go

@@ -836,6 +836,7 @@ func (m *Master) getServersToValidate(c *Config) map[string]apiserver.Server {
 			addr = etcdUrl.Host
 			port = 4001
 		}
+		// TODO: etcd health checking should be abstracted in the storage tier
 		serversToValidate[fmt.Sprintf("etcd-%d", ix)] = apiserver.Server{Addr: addr, Port: port, Path: "/health", Validate: etcdutil.EtcdHealthCheck}
 	}
 	return serversToValidate

pkg/master/master_test.go

@@ -47,7 +47,6 @@ import (
 	etcdstorage "k8s.io/kubernetes/pkg/storage/etcd"
 	"k8s.io/kubernetes/pkg/storage/etcd/etcdtest"
 	etcdtesting "k8s.io/kubernetes/pkg/storage/etcd/testing"
-	etcdutil "k8s.io/kubernetes/pkg/storage/etcd/util"
 	"k8s.io/kubernetes/pkg/util"
 	"k8s.io/kubernetes/pkg/util/intstr"
 
@@ -789,7 +788,7 @@ func testInstallThirdPartyAPIDeleteVersion(t *testing.T, version string) {
 	thirdPartyObj := extensions.ThirdPartyResourceData{}
 	err = master.thirdPartyStorage.Get(
 		context.TODO(), expectedDeletedKey, &thirdPartyObj, false)
-	if !etcdutil.IsEtcdNotFound(err) {
+	if !storage.IsNotFound(err) {
 		t.Errorf("expected deletion didn't happen: %v", err)
 	}
 }
@@ -876,7 +875,7 @@ func testInstallThirdPartyResourceRemove(t *testing.T, version string) {
 	for _, key := range expectedDeletedKeys {
 		thirdPartyObj := extensions.ThirdPartyResourceData{}
 		err := master.thirdPartyStorage.Get(context.TODO(), key, &thirdPartyObj, false)
-		if !etcdutil.IsEtcdNotFound(err) {
+		if !storage.IsNotFound(err) {
 			t.Errorf("expected deletion didn't happen: %v", err)
 		}
 	}

pkg/registry/service/allocator/etcd/etcd.go

@@ -28,7 +28,6 @@ import (
 	"k8s.io/kubernetes/pkg/registry/service/allocator"
 	"k8s.io/kubernetes/pkg/runtime"
 	"k8s.io/kubernetes/pkg/storage"
-	etcdutil "k8s.io/kubernetes/pkg/storage/etcd/util"
 
 	"golang.org/x/net/context"
 )
@@ -174,7 +173,7 @@ func (e *Etcd) Refresh() (*api.RangeAllocation, error) {
 
 	existing := &api.RangeAllocation{}
 	if err := e.storage.Get(context.TODO(), e.baseKey, existing, false); err != nil {
-		if etcdutil.IsEtcdNotFound(err) {
+		if storage.IsNotFound(err) {
 			return nil, nil
 		}
 		return nil, etcderr.InterpretGetError(err, e.kind, "")

pkg/storage/errors.go

@@ -0,0 +1,45 @@
+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+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
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package storage
+
+import (
+	etcdutil "k8s.io/kubernetes/pkg/storage/etcd/util"
+)
+
+// IsNotFound returns true if and only if err is "key" not found error.
+func IsNotFound(err error) bool {
+	// TODO: add alternate storage error here
+	return etcdutil.IsEtcdNotFound(err)
+}
+
+// IsNodeExist returns true if and only if err is an node already exist error.
+func IsNodeExist(err error) bool {
+	// TODO: add alternate storage error here
+	return etcdutil.IsEtcdNodeExist(err)
+}
+
+// IsUnreachable returns true if and only if err indicates the server could not be reached.
+func IsUnreachable(err error) bool {
+	// TODO: add alternate storage error here
+	return etcdutil.IsEtcdUnreachable(err)
+}
+
+// IsTestFailed returns true if and only if err is a write conflict.
+func IsTestFailed(err error) bool {
+	// TODO: add alternate storage error here
+	return etcdutil.IsEtcdTestFailed(err)
+}