diff options
Diffstat (limited to 'vendor/google.golang.org/grpc/internal/resolver')
3 files changed, 257 insertions, 13 deletions
diff --git a/vendor/google.golang.org/grpc/internal/resolver/config_selector.go b/vendor/google.golang.org/grpc/internal/resolver/config_selector.go new file mode 100644 index 000000000..5e7f36703 --- /dev/null +++ b/vendor/google.golang.org/grpc/internal/resolver/config_selector.go @@ -0,0 +1,164 @@ +/* + * + * Copyright 2020 gRPC authors. + * + * 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 resolver provides internal resolver-related functionality. +package resolver + +import ( + "context" + "sync" + + "google.golang.org/grpc/internal/serviceconfig" + "google.golang.org/grpc/metadata" + "google.golang.org/grpc/resolver" +) + +// ConfigSelector controls what configuration to use for every RPC. +type ConfigSelector interface { + // Selects the configuration for the RPC, or terminates it using the error. + // This error will be converted by the gRPC library to a status error with + // code UNKNOWN if it is not returned as a status error. + SelectConfig(RPCInfo) (*RPCConfig, error) +} + +// RPCInfo contains RPC information needed by a ConfigSelector. +type RPCInfo struct { + // Context is the user's context for the RPC and contains headers and + // application timeout. It is passed for interception purposes and for + // efficiency reasons. SelectConfig should not be blocking. + Context context.Context + Method string // i.e. "/Service/Method" +} + +// RPCConfig describes the configuration to use for each RPC. +type RPCConfig struct { + // The context to use for the remainder of the RPC; can pass info to LB + // policy or affect timeout or metadata. + Context context.Context + MethodConfig serviceconfig.MethodConfig // configuration to use for this RPC + OnCommitted func() // Called when the RPC has been committed (retries no longer possible) + Interceptor ClientInterceptor +} + +// ClientStream is the same as grpc.ClientStream, but defined here for circular +// dependency reasons. +type ClientStream interface { + // Header returns the header metadata received from the server if there + // is any. It blocks if the metadata is not ready to read. + Header() (metadata.MD, error) + // Trailer returns the trailer metadata from the server, if there is any. + // It must only be called after stream.CloseAndRecv has returned, or + // stream.Recv has returned a non-nil error (including io.EOF). + Trailer() metadata.MD + // CloseSend closes the send direction of the stream. It closes the stream + // when non-nil error is met. It is also not safe to call CloseSend + // concurrently with SendMsg. + CloseSend() error + // Context returns the context for this stream. + // + // It should not be called until after Header or RecvMsg has returned. Once + // called, subsequent client-side retries are disabled. + Context() context.Context + // SendMsg is generally called by generated code. On error, SendMsg aborts + // the stream. If the error was generated by the client, the status is + // returned directly; otherwise, io.EOF is returned and the status of + // the stream may be discovered using RecvMsg. + // + // SendMsg blocks until: + // - There is sufficient flow control to schedule m with the transport, or + // - The stream is done, or + // - The stream breaks. + // + // SendMsg does not wait until the message is received by the server. An + // untimely stream closure may result in lost messages. To ensure delivery, + // users should ensure the RPC completed successfully using RecvMsg. + // + // It is safe to have a goroutine calling SendMsg and another goroutine + // calling RecvMsg on the same stream at the same time, but it is not safe + // to call SendMsg on the same stream in different goroutines. It is also + // not safe to call CloseSend concurrently with SendMsg. + SendMsg(m interface{}) error + // RecvMsg blocks until it receives a message into m or the stream is + // done. It returns io.EOF when the stream completes successfully. On + // any other error, the stream is aborted and the error contains the RPC + // status. + // + // It is safe to have a goroutine calling SendMsg and another goroutine + // calling RecvMsg on the same stream at the same time, but it is not + // safe to call RecvMsg on the same stream in different goroutines. + RecvMsg(m interface{}) error +} + +// ClientInterceptor is an interceptor for gRPC client streams. +type ClientInterceptor interface { + // NewStream produces a ClientStream for an RPC which may optionally use + // the provided function to produce a stream for delegation. Note: + // RPCInfo.Context should not be used (will be nil). + // + // done is invoked when the RPC is finished using its connection, or could + // not be assigned a connection. RPC operations may still occur on + // ClientStream after done is called, since the interceptor is invoked by + // application-layer operations. done must never be nil when called. + NewStream(ctx context.Context, ri RPCInfo, done func(), newStream func(ctx context.Context, done func()) (ClientStream, error)) (ClientStream, error) +} + +// ServerInterceptor is unimplementable; do not use. +type ServerInterceptor interface { + notDefined() +} + +type csKeyType string + +const csKey = csKeyType("grpc.internal.resolver.configSelector") + +// SetConfigSelector sets the config selector in state and returns the new +// state. +func SetConfigSelector(state resolver.State, cs ConfigSelector) resolver.State { + state.Attributes = state.Attributes.WithValues(csKey, cs) + return state +} + +// GetConfigSelector retrieves the config selector from state, if present, and +// returns it or nil if absent. +func GetConfigSelector(state resolver.State) ConfigSelector { + cs, _ := state.Attributes.Value(csKey).(ConfigSelector) + return cs +} + +// SafeConfigSelector allows for safe switching of ConfigSelector +// implementations such that previous values are guaranteed to not be in use +// when UpdateConfigSelector returns. +type SafeConfigSelector struct { + mu sync.RWMutex + cs ConfigSelector +} + +// UpdateConfigSelector swaps to the provided ConfigSelector and blocks until +// all uses of the previous ConfigSelector have completed. +func (scs *SafeConfigSelector) UpdateConfigSelector(cs ConfigSelector) { + scs.mu.Lock() + defer scs.mu.Unlock() + scs.cs = cs +} + +// SelectConfig defers to the current ConfigSelector in scs. +func (scs *SafeConfigSelector) SelectConfig(r RPCInfo) (*RPCConfig, error) { + scs.mu.RLock() + defer scs.mu.RUnlock() + return scs.cs.SelectConfig(r) +} diff --git a/vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go b/vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go index 304235566..03825bbe7 100644 --- a/vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go +++ b/vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go @@ -34,6 +34,7 @@ import ( grpclbstate "google.golang.org/grpc/balancer/grpclb/state" "google.golang.org/grpc/grpclog" + "google.golang.org/grpc/internal/backoff" "google.golang.org/grpc/internal/envconfig" "google.golang.org/grpc/internal/grpcrand" "google.golang.org/grpc/resolver" @@ -46,6 +47,13 @@ var EnableSRVLookups = false var logger = grpclog.Component("dns") +// Globals to stub out in tests. TODO: Perhaps these two can be combined into a +// single variable for testing the resolver? +var ( + newTimer = time.NewTimer + newTimerDNSResRate = time.NewTimer +) + func init() { resolver.Register(NewBuilder()) } @@ -143,7 +151,6 @@ func (b *dnsBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts d.wg.Add(1) go d.watcher() - d.ResolveNow(resolver.ResolveNowOptions{}) return d, nil } @@ -201,28 +208,38 @@ func (d *dnsResolver) Close() { func (d *dnsResolver) watcher() { defer d.wg.Done() + backoffIndex := 1 for { - select { - case <-d.ctx.Done(): - return - case <-d.rn: - } - state, err := d.lookup() if err != nil { + // Report error to the underlying grpc.ClientConn. d.cc.ReportError(err) } else { - d.cc.UpdateState(*state) + err = d.cc.UpdateState(*state) } - // Sleep to prevent excessive re-resolutions. Incoming resolution requests - // will be queued in d.rn. - t := time.NewTimer(minDNSResRate) + var timer *time.Timer + if err == nil { + // Success resolving, wait for the next ResolveNow. However, also wait 30 seconds at the very least + // to prevent constantly re-resolving. + backoffIndex = 1 + timer = newTimerDNSResRate(minDNSResRate) + select { + case <-d.ctx.Done(): + timer.Stop() + return + case <-d.rn: + } + } else { + // Poll on an error found in DNS Resolver or an error received from ClientConn. + timer = newTimer(backoff.DefaultExponential.Backoff(backoffIndex)) + backoffIndex++ + } select { - case <-t.C: case <-d.ctx.Done(): - t.Stop() + timer.Stop() return + case <-timer.C: } } } diff --git a/vendor/google.golang.org/grpc/internal/resolver/unix/unix.go b/vendor/google.golang.org/grpc/internal/resolver/unix/unix.go new file mode 100644 index 000000000..0d5a811dd --- /dev/null +++ b/vendor/google.golang.org/grpc/internal/resolver/unix/unix.go @@ -0,0 +1,63 @@ +/* + * + * Copyright 2020 gRPC authors. + * + * 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 unix implements a resolver for unix targets. +package unix + +import ( + "fmt" + + "google.golang.org/grpc/internal/transport/networktype" + "google.golang.org/grpc/resolver" +) + +const unixScheme = "unix" +const unixAbstractScheme = "unix-abstract" + +type builder struct { + scheme string +} + +func (b *builder) Build(target resolver.Target, cc resolver.ClientConn, _ resolver.BuildOptions) (resolver.Resolver, error) { + if target.Authority != "" { + return nil, fmt.Errorf("invalid (non-empty) authority: %v", target.Authority) + } + addr := resolver.Address{Addr: target.Endpoint} + if b.scheme == unixAbstractScheme { + // prepend "\x00" to address for unix-abstract + addr.Addr = "\x00" + addr.Addr + } + cc.UpdateState(resolver.State{Addresses: []resolver.Address{networktype.Set(addr, "unix")}}) + return &nopResolver{}, nil +} + +func (b *builder) Scheme() string { + return b.scheme +} + +type nopResolver struct { +} + +func (*nopResolver) ResolveNow(resolver.ResolveNowOptions) {} + +func (*nopResolver) Close() {} + +func init() { + resolver.Register(&builder{scheme: unixScheme}) + resolver.Register(&builder{scheme: unixAbstractScheme}) +} |