ref(tiller): dry up client/server version checks

pkg/tiller/release_history.go

@@ -25,10 +25,6 @@ import (
 
 // GetHistory gets the history for a given release.
 func (s *ReleaseServer) GetHistory(ctx context.Context, req *tpb.GetHistoryRequest) (*tpb.GetHistoryResponse, error) {
-	if !checkClientVersion(ctx) {
-		return nil, errIncompatibleVersion
-	}
-
 	h, err := s.env.Releases.History(req.Name)
 	if err != nil {
 		return nil, err

pkg/tiller/release_server.go

@@ -27,8 +27,6 @@ import (
 
 	"github.com/technosophos/moniker"
 	ctx "golang.org/x/net/context"
-	"google.golang.org/grpc"
-	"google.golang.org/grpc/metadata"
 	"k8s.io/kubernetes/pkg/api/unversioned"
 	"k8s.io/kubernetes/pkg/client/clientset_generated/internalclientset"
 	"k8s.io/kubernetes/pkg/client/typed/discovery"
@@ -65,8 +63,6 @@ var (
 	errMissingRelease = errors.New("no release provided")
 	// errInvalidRevision indicates that an invalid release revision number was provided.
 	errInvalidRevision = errors.New("invalid release revision")
-	// errIncompatibleVersion indicates incompatible client/server versions.
-	errIncompatibleVersion = errors.New("client version is incompatible")
 )
 
 // ListDefaultLimit is the default limit for number of items returned in a list.
@@ -83,17 +79,6 @@ var ListDefaultLimit int64 = 512
 // prevents an empty string from matching.
 var ValidName = regexp.MustCompile("^(([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9])+$")
 
-// maxMsgSize use 10MB as the default message size limit.
-// grpc library default is 4MB
-var maxMsgSize = 1024 * 1024 * 10
-
-// NewServer creates a new grpc server.
-func NewServer() *grpc.Server {
-	return grpc.NewServer(
-		grpc.MaxMsgSize(maxMsgSize),
-	)
-}
-
 // ReleaseServer implements the server-side gRPC endpoint for the HAPI services.
 type ReleaseServer struct {
 	env       *environment.Environment
@@ -108,21 +93,8 @@ func NewReleaseServer(env *environment.Environment, clientset internalclientset.
 	}
 }
 
-func getVersion(c ctx.Context) string {
-	if md, ok := metadata.FromContext(c); ok {
-		if v, ok := md["x-helm-api-client"]; ok {
-			return v[0]
-		}
-	}
-	return ""
-}
-
 // ListReleases lists the releases found by the server.
 func (s *ReleaseServer) ListReleases(req *services.ListReleasesRequest, stream services.ReleaseService_ListReleasesServer) error {
-	if !checkClientVersion(stream.Context()) {
-		return errIncompatibleVersion
-	}
-
 	if len(req.StatusCodes) == 0 {
 		req.StatusCodes = []release.Status_Code{release.Status_DEPLOYED}
 	}
@@ -226,17 +198,8 @@ func (s *ReleaseServer) GetVersion(c ctx.Context, req *services.GetVersionReques
 	return &services.GetVersionResponse{Version: v}, nil
 }
 
-func checkClientVersion(c ctx.Context) bool {
-	v := getVersion(c)
-	return version.IsCompatible(v, version.Version)
-}
-
 // GetReleaseStatus gets the status information for a named release.
 func (s *ReleaseServer) GetReleaseStatus(c ctx.Context, req *services.GetReleaseStatusRequest) (*services.GetReleaseStatusResponse, error) {
-	if !checkClientVersion(c) {
-		return nil, errIncompatibleVersion
-	}
-
 	if !ValidName.MatchString(req.Name) {
 		return nil, errMissingRelease
 	}
@@ -283,10 +246,6 @@ func (s *ReleaseServer) GetReleaseStatus(c ctx.Context, req *services.GetRelease
 
 // GetReleaseContent gets all of the stored information for the given release.
 func (s *ReleaseServer) GetReleaseContent(c ctx.Context, req *services.GetReleaseContentRequest) (*services.GetReleaseContentResponse, error) {
-	if !checkClientVersion(c) {
-		return nil, errIncompatibleVersion
-	}
-
 	if !ValidName.MatchString(req.Name) {
 		return nil, errMissingRelease
 	}
@@ -302,10 +261,6 @@ func (s *ReleaseServer) GetReleaseContent(c ctx.Context, req *services.GetReleas
 
 // UpdateRelease takes an existing release and new information, and upgrades the release.
 func (s *ReleaseServer) UpdateRelease(c ctx.Context, req *services.UpdateReleaseRequest) (*services.UpdateReleaseResponse, error) {
-	if !checkClientVersion(c) {
-		return nil, errIncompatibleVersion
-	}
-
 	currentRelease, updatedRelease, err := s.prepareUpdate(req)
 	if err != nil {
 		return nil, err
@@ -440,10 +395,6 @@ func (s *ReleaseServer) prepareUpdate(req *services.UpdateReleaseRequest) (*rele
 
 // RollbackRelease rolls back to a previous version of the given release.
 func (s *ReleaseServer) RollbackRelease(c ctx.Context, req *services.RollbackReleaseRequest) (*services.RollbackReleaseResponse, error) {
-	if !checkClientVersion(c) {
-		return nil, errIncompatibleVersion
-	}
-
 	currentRelease, targetRelease, err := s.prepareRollback(req)
 	if err != nil {
 		return nil, err
@@ -617,10 +568,6 @@ func (s *ReleaseServer) engine(ch *chart.Chart) environment.Engine {
 
 // InstallRelease installs a release and stores the release record.
 func (s *ReleaseServer) InstallRelease(c ctx.Context, req *services.InstallReleaseRequest) (*services.InstallReleaseResponse, error) {
-	if !checkClientVersion(c) {
-		return nil, errIncompatibleVersion
-	}
-
 	rel, err := s.prepareRelease(req)
 	if err != nil {
 		log.Printf("Failed install prepare step: %s", err)
@@ -924,10 +871,6 @@ func (s *ReleaseServer) purgeReleases(rels ...*release.Release) error {
 
 // UninstallRelease deletes all of the resources associated with this release, and marks the release DELETED.
 func (s *ReleaseServer) UninstallRelease(c ctx.Context, req *services.UninstallReleaseRequest) (*services.UninstallReleaseResponse, error) {
-	if !checkClientVersion(c) {
-		return nil, errIncompatibleVersion
-	}
-
 	if !ValidName.MatchString(req.Name) {
 		log.Printf("uninstall: Release not found: %s", req.Name)
 		return nil, errMissingRelease

pkg/tiller/server.go

@@ -0,0 +1,89 @@
+/*
+Copyright 2016 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 tiller
+
+import (
+	"fmt"
+	"log"
+	"strings"
+
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/metadata"
+
+	"k8s.io/helm/pkg/version"
+)
+
+// maxMsgSize use 10MB as the default message size limit.
+// grpc library default is 4MB
+var maxMsgSize = 1024 * 1024 * 10
+
+// NewServer creates a new grpc server.
+func NewServer() *grpc.Server {
+	return grpc.NewServer(
+		grpc.MaxMsgSize(maxMsgSize),
+		grpc.UnaryInterceptor(newUnaryInterceptor()),
+		grpc.StreamInterceptor(newStreamInterceptor()),
+	)
+}
+
+func newUnaryInterceptor() grpc.UnaryServerInterceptor {
+	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
+		if err := checkClientVersion(ctx); err != nil {
+			// whitelist GetVersion() from the version check
+			if _, m := splitMethod(info.FullMethod); m != "GetVersion" {
+				log.Println(err)
+				return nil, err
+			}
+		}
+		return handler(ctx, req)
+	}
+}
+
+func newStreamInterceptor() grpc.StreamServerInterceptor {
+	return func(srv interface{}, ss grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+		if err := checkClientVersion(ss.Context()); err != nil {
+			log.Println(err)
+			return err
+		}
+		return handler(srv, ss)
+	}
+}
+
+func splitMethod(fullMethod string) (string, string) {
+	if frags := strings.Split(fullMethod, "/"); len(frags) == 3 {
+		return frags[1], frags[2]
+	}
+	return "unknown", "unknown"
+}
+
+func versionFromContext(ctx context.Context) string {
+	if md, ok := metadata.FromContext(ctx); ok {
+		if v, ok := md["x-helm-api-client"]; ok && len(v) > 0 {
+			return v[0]
+		}
+	}
+	return ""
+}
+
+func checkClientVersion(ctx context.Context) error {
+	clientVersion := versionFromContext(ctx)
+	if !version.IsCompatible(clientVersion, version.Version) {
+		return fmt.Errorf("incompatible versions client: %s server: %s", clientVersion, version.Version)
+	}
+	return nil
+}