[VOL-4289] Proto changes for gRPC migration
Change-Id: I317a0a865ccf78d0c37aa229c50d293a3f66c8bb
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 0000000..be7e13d
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/resolver/config_selector.go
@@ -0,0 +1,167 @@
+/*
+ *
+ * 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 an interceptor for incoming RPC's on gRPC server side.
+type ServerInterceptor interface {
+ // AllowRPC checks if an incoming RPC is allowed to proceed based on
+ // information about connection RPC was received on, and HTTP Headers. This
+ // information will be piped into context.
+ AllowRPC(ctx context.Context) error // TODO: Make this a real interceptor for filters such as rate limiting.
+}
+
+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
new file mode 100644
index 0000000..75301c5
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go
@@ -0,0 +1,458 @@
+/*
+ *
+ * Copyright 2018 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 dns implements a dns resolver to be installed as the default resolver
+// in grpc.
+package dns
+
+import (
+ "context"
+ "encoding/json"
+ "errors"
+ "fmt"
+ "net"
+ "os"
+ "strconv"
+ "strings"
+ "sync"
+ "time"
+
+ 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"
+ "google.golang.org/grpc/serviceconfig"
+)
+
+// EnableSRVLookups controls whether the DNS resolver attempts to fetch gRPCLB
+// addresses from SRV records. Must not be changed after init time.
+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())
+}
+
+const (
+ defaultPort = "443"
+ defaultDNSSvrPort = "53"
+ golang = "GO"
+ // txtPrefix is the prefix string to be prepended to the host name for txt record lookup.
+ txtPrefix = "_grpc_config."
+ // In DNS, service config is encoded in a TXT record via the mechanism
+ // described in RFC-1464 using the attribute name grpc_config.
+ txtAttribute = "grpc_config="
+)
+
+var (
+ errMissingAddr = errors.New("dns resolver: missing address")
+
+ // Addresses ending with a colon that is supposed to be the separator
+ // between host and port is not allowed. E.g. "::" is a valid address as
+ // it is an IPv6 address (host only) and "[::]:" is invalid as it ends with
+ // a colon as the host and port separator
+ errEndsWithColon = errors.New("dns resolver: missing port after port-separator colon")
+)
+
+var (
+ defaultResolver netResolver = net.DefaultResolver
+ // To prevent excessive re-resolution, we enforce a rate limit on DNS
+ // resolution requests.
+ minDNSResRate = 30 * time.Second
+)
+
+var customAuthorityDialler = func(authority string) func(ctx context.Context, network, address string) (net.Conn, error) {
+ return func(ctx context.Context, network, address string) (net.Conn, error) {
+ var dialer net.Dialer
+ return dialer.DialContext(ctx, network, authority)
+ }
+}
+
+var customAuthorityResolver = func(authority string) (netResolver, error) {
+ host, port, err := parseTarget(authority, defaultDNSSvrPort)
+ if err != nil {
+ return nil, err
+ }
+
+ authorityWithPort := net.JoinHostPort(host, port)
+
+ return &net.Resolver{
+ PreferGo: true,
+ Dial: customAuthorityDialler(authorityWithPort),
+ }, nil
+}
+
+// NewBuilder creates a dnsBuilder which is used to factory DNS resolvers.
+func NewBuilder() resolver.Builder {
+ return &dnsBuilder{}
+}
+
+type dnsBuilder struct{}
+
+// Build creates and starts a DNS resolver that watches the name resolution of the target.
+func (b *dnsBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions) (resolver.Resolver, error) {
+ host, port, err := parseTarget(target.Endpoint, defaultPort)
+ if err != nil {
+ return nil, err
+ }
+
+ // IP address.
+ if ipAddr, ok := formatIP(host); ok {
+ addr := []resolver.Address{{Addr: ipAddr + ":" + port}}
+ cc.UpdateState(resolver.State{Addresses: addr})
+ return deadResolver{}, nil
+ }
+
+ // DNS address (non-IP).
+ ctx, cancel := context.WithCancel(context.Background())
+ d := &dnsResolver{
+ host: host,
+ port: port,
+ ctx: ctx,
+ cancel: cancel,
+ cc: cc,
+ rn: make(chan struct{}, 1),
+ disableServiceConfig: opts.DisableServiceConfig,
+ }
+
+ if target.Authority == "" {
+ d.resolver = defaultResolver
+ } else {
+ d.resolver, err = customAuthorityResolver(target.Authority)
+ if err != nil {
+ return nil, err
+ }
+ }
+
+ d.wg.Add(1)
+ go d.watcher()
+ return d, nil
+}
+
+// Scheme returns the naming scheme of this resolver builder, which is "dns".
+func (b *dnsBuilder) Scheme() string {
+ return "dns"
+}
+
+type netResolver interface {
+ LookupHost(ctx context.Context, host string) (addrs []string, err error)
+ LookupSRV(ctx context.Context, service, proto, name string) (cname string, addrs []*net.SRV, err error)
+ LookupTXT(ctx context.Context, name string) (txts []string, err error)
+}
+
+// deadResolver is a resolver that does nothing.
+type deadResolver struct{}
+
+func (deadResolver) ResolveNow(resolver.ResolveNowOptions) {}
+
+func (deadResolver) Close() {}
+
+// dnsResolver watches for the name resolution update for a non-IP target.
+type dnsResolver struct {
+ host string
+ port string
+ resolver netResolver
+ ctx context.Context
+ cancel context.CancelFunc
+ cc resolver.ClientConn
+ // rn channel is used by ResolveNow() to force an immediate resolution of the target.
+ rn chan struct{}
+ // wg is used to enforce Close() to return after the watcher() goroutine has finished.
+ // Otherwise, data race will be possible. [Race Example] in dns_resolver_test we
+ // replace the real lookup functions with mocked ones to facilitate testing.
+ // If Close() doesn't wait for watcher() goroutine finishes, race detector sometimes
+ // will warns lookup (READ the lookup function pointers) inside watcher() goroutine
+ // has data race with replaceNetFunc (WRITE the lookup function pointers).
+ wg sync.WaitGroup
+ disableServiceConfig bool
+}
+
+// ResolveNow invoke an immediate resolution of the target that this dnsResolver watches.
+func (d *dnsResolver) ResolveNow(resolver.ResolveNowOptions) {
+ select {
+ case d.rn <- struct{}{}:
+ default:
+ }
+}
+
+// Close closes the dnsResolver.
+func (d *dnsResolver) Close() {
+ d.cancel()
+ d.wg.Wait()
+}
+
+func (d *dnsResolver) watcher() {
+ defer d.wg.Done()
+ backoffIndex := 1
+ for {
+ state, err := d.lookup()
+ if err != nil {
+ // Report error to the underlying grpc.ClientConn.
+ d.cc.ReportError(err)
+ } else {
+ err = d.cc.UpdateState(*state)
+ }
+
+ 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 <-d.ctx.Done():
+ timer.Stop()
+ return
+ case <-timer.C:
+ }
+ }
+}
+
+func (d *dnsResolver) lookupSRV() ([]resolver.Address, error) {
+ if !EnableSRVLookups {
+ return nil, nil
+ }
+ var newAddrs []resolver.Address
+ _, srvs, err := d.resolver.LookupSRV(d.ctx, "grpclb", "tcp", d.host)
+ if err != nil {
+ err = handleDNSError(err, "SRV") // may become nil
+ return nil, err
+ }
+ for _, s := range srvs {
+ lbAddrs, err := d.resolver.LookupHost(d.ctx, s.Target)
+ if err != nil {
+ err = handleDNSError(err, "A") // may become nil
+ if err == nil {
+ // If there are other SRV records, look them up and ignore this
+ // one that does not exist.
+ continue
+ }
+ return nil, err
+ }
+ for _, a := range lbAddrs {
+ ip, ok := formatIP(a)
+ if !ok {
+ return nil, fmt.Errorf("dns: error parsing A record IP address %v", a)
+ }
+ addr := ip + ":" + strconv.Itoa(int(s.Port))
+ newAddrs = append(newAddrs, resolver.Address{Addr: addr, ServerName: s.Target})
+ }
+ }
+ return newAddrs, nil
+}
+
+func handleDNSError(err error, lookupType string) error {
+ if dnsErr, ok := err.(*net.DNSError); ok && !dnsErr.IsTimeout && !dnsErr.IsTemporary {
+ // Timeouts and temporary errors should be communicated to gRPC to
+ // attempt another DNS query (with backoff). Other errors should be
+ // suppressed (they may represent the absence of a TXT record).
+ return nil
+ }
+ if err != nil {
+ err = fmt.Errorf("dns: %v record lookup error: %v", lookupType, err)
+ logger.Info(err)
+ }
+ return err
+}
+
+func (d *dnsResolver) lookupTXT() *serviceconfig.ParseResult {
+ ss, err := d.resolver.LookupTXT(d.ctx, txtPrefix+d.host)
+ if err != nil {
+ if envconfig.TXTErrIgnore {
+ return nil
+ }
+ if err = handleDNSError(err, "TXT"); err != nil {
+ return &serviceconfig.ParseResult{Err: err}
+ }
+ return nil
+ }
+ var res string
+ for _, s := range ss {
+ res += s
+ }
+
+ // TXT record must have "grpc_config=" attribute in order to be used as service config.
+ if !strings.HasPrefix(res, txtAttribute) {
+ logger.Warningf("dns: TXT record %v missing %v attribute", res, txtAttribute)
+ // This is not an error; it is the equivalent of not having a service config.
+ return nil
+ }
+ sc := canaryingSC(strings.TrimPrefix(res, txtAttribute))
+ return d.cc.ParseServiceConfig(sc)
+}
+
+func (d *dnsResolver) lookupHost() ([]resolver.Address, error) {
+ addrs, err := d.resolver.LookupHost(d.ctx, d.host)
+ if err != nil {
+ err = handleDNSError(err, "A")
+ return nil, err
+ }
+ newAddrs := make([]resolver.Address, 0, len(addrs))
+ for _, a := range addrs {
+ ip, ok := formatIP(a)
+ if !ok {
+ return nil, fmt.Errorf("dns: error parsing A record IP address %v", a)
+ }
+ addr := ip + ":" + d.port
+ newAddrs = append(newAddrs, resolver.Address{Addr: addr})
+ }
+ return newAddrs, nil
+}
+
+func (d *dnsResolver) lookup() (*resolver.State, error) {
+ srv, srvErr := d.lookupSRV()
+ addrs, hostErr := d.lookupHost()
+ if hostErr != nil && (srvErr != nil || len(srv) == 0) {
+ return nil, hostErr
+ }
+
+ state := resolver.State{Addresses: addrs}
+ if len(srv) > 0 {
+ state = grpclbstate.Set(state, &grpclbstate.State{BalancerAddresses: srv})
+ }
+ if !d.disableServiceConfig {
+ state.ServiceConfig = d.lookupTXT()
+ }
+ return &state, nil
+}
+
+// formatIP returns ok = false if addr is not a valid textual representation of an IP address.
+// If addr is an IPv4 address, return the addr and ok = true.
+// If addr is an IPv6 address, return the addr enclosed in square brackets and ok = true.
+func formatIP(addr string) (addrIP string, ok bool) {
+ ip := net.ParseIP(addr)
+ if ip == nil {
+ return "", false
+ }
+ if ip.To4() != nil {
+ return addr, true
+ }
+ return "[" + addr + "]", true
+}
+
+// parseTarget takes the user input target string and default port, returns formatted host and port info.
+// If target doesn't specify a port, set the port to be the defaultPort.
+// If target is in IPv6 format and host-name is enclosed in square brackets, brackets
+// are stripped when setting the host.
+// examples:
+// target: "www.google.com" defaultPort: "443" returns host: "www.google.com", port: "443"
+// target: "ipv4-host:80" defaultPort: "443" returns host: "ipv4-host", port: "80"
+// target: "[ipv6-host]" defaultPort: "443" returns host: "ipv6-host", port: "443"
+// target: ":80" defaultPort: "443" returns host: "localhost", port: "80"
+func parseTarget(target, defaultPort string) (host, port string, err error) {
+ if target == "" {
+ return "", "", errMissingAddr
+ }
+ if ip := net.ParseIP(target); ip != nil {
+ // target is an IPv4 or IPv6(without brackets) address
+ return target, defaultPort, nil
+ }
+ if host, port, err = net.SplitHostPort(target); err == nil {
+ if port == "" {
+ // If the port field is empty (target ends with colon), e.g. "[::1]:", this is an error.
+ return "", "", errEndsWithColon
+ }
+ // target has port, i.e ipv4-host:port, [ipv6-host]:port, host-name:port
+ if host == "" {
+ // Keep consistent with net.Dial(): If the host is empty, as in ":80", the local system is assumed.
+ host = "localhost"
+ }
+ return host, port, nil
+ }
+ if host, port, err = net.SplitHostPort(target + ":" + defaultPort); err == nil {
+ // target doesn't have port
+ return host, port, nil
+ }
+ return "", "", fmt.Errorf("invalid target address %v, error info: %v", target, err)
+}
+
+type rawChoice struct {
+ ClientLanguage *[]string `json:"clientLanguage,omitempty"`
+ Percentage *int `json:"percentage,omitempty"`
+ ClientHostName *[]string `json:"clientHostName,omitempty"`
+ ServiceConfig *json.RawMessage `json:"serviceConfig,omitempty"`
+}
+
+func containsString(a *[]string, b string) bool {
+ if a == nil {
+ return true
+ }
+ for _, c := range *a {
+ if c == b {
+ return true
+ }
+ }
+ return false
+}
+
+func chosenByPercentage(a *int) bool {
+ if a == nil {
+ return true
+ }
+ return grpcrand.Intn(100)+1 <= *a
+}
+
+func canaryingSC(js string) string {
+ if js == "" {
+ return ""
+ }
+ var rcs []rawChoice
+ err := json.Unmarshal([]byte(js), &rcs)
+ if err != nil {
+ logger.Warningf("dns: error parsing service config json: %v", err)
+ return ""
+ }
+ cliHostname, err := os.Hostname()
+ if err != nil {
+ logger.Warningf("dns: error getting client hostname: %v", err)
+ return ""
+ }
+ var sc string
+ for _, c := range rcs {
+ if !containsString(c.ClientLanguage, golang) ||
+ !chosenByPercentage(c.Percentage) ||
+ !containsString(c.ClientHostName, cliHostname) ||
+ c.ServiceConfig == nil {
+ continue
+ }
+ sc = string(*c.ServiceConfig)
+ break
+ }
+ return sc
+}
diff --git a/vendor/google.golang.org/grpc/internal/resolver/passthrough/passthrough.go b/vendor/google.golang.org/grpc/internal/resolver/passthrough/passthrough.go
new file mode 100644
index 0000000..520d922
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/resolver/passthrough/passthrough.go
@@ -0,0 +1,57 @@
+/*
+ *
+ * Copyright 2017 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 passthrough implements a pass-through resolver. It sends the target
+// name without scheme back to gRPC as resolved address.
+package passthrough
+
+import "google.golang.org/grpc/resolver"
+
+const scheme = "passthrough"
+
+type passthroughBuilder struct{}
+
+func (*passthroughBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions) (resolver.Resolver, error) {
+ r := &passthroughResolver{
+ target: target,
+ cc: cc,
+ }
+ r.start()
+ return r, nil
+}
+
+func (*passthroughBuilder) Scheme() string {
+ return scheme
+}
+
+type passthroughResolver struct {
+ target resolver.Target
+ cc resolver.ClientConn
+}
+
+func (r *passthroughResolver) start() {
+ r.cc.UpdateState(resolver.State{Addresses: []resolver.Address{{Addr: r.target.Endpoint}}})
+}
+
+func (*passthroughResolver) ResolveNow(o resolver.ResolveNowOptions) {}
+
+func (*passthroughResolver) Close() {}
+
+func init() {
+ resolver.Register(&passthroughBuilder{})
+}
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 0000000..0d5a811
--- /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})
+}