dependabot[bot] 4c2af94577 Bump google.golang.org/grpc from 1.70.0 to 1.71.0 (#4809)
Bumps [google.golang.org/grpc](https://github.com/grpc/grpc-go) from 1.70.0 to 1.71.0.
- [Release notes](https://github.com/grpc/grpc-go/releases)
- [Commits](https://github.com/grpc/grpc-go/compare/v1.70.0...v1.71.0)

---
updated-dependencies:
- dependency-name: google.golang.org/grpc
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
2025-03-10 11:08:09 +10:00

330 lines
13 KiB
Go

/*
*
* Copyright 2024 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 delegatingresolver implements a resolver capable of resolving both
// target URIs and proxy addresses.
package delegatingresolver
import (
"fmt"
"net/http"
"net/url"
"sync"
"google.golang.org/grpc/grpclog"
"google.golang.org/grpc/internal/proxyattributes"
"google.golang.org/grpc/resolver"
"google.golang.org/grpc/serviceconfig"
)
var (
logger = grpclog.Component("delegating-resolver")
// HTTPSProxyFromEnvironment will be overwritten in the tests
HTTPSProxyFromEnvironment = http.ProxyFromEnvironment
)
// delegatingResolver manages both target URI and proxy address resolution by
// delegating these tasks to separate child resolvers. Essentially, it acts as
// a intermediary between the gRPC ClientConn and the child resolvers.
//
// It implements the [resolver.Resolver] interface.
type delegatingResolver struct {
target resolver.Target // parsed target URI to be resolved
cc resolver.ClientConn // gRPC ClientConn
targetResolver resolver.Resolver // resolver for the target URI, based on its scheme
proxyResolver resolver.Resolver // resolver for the proxy URI; nil if no proxy is configured
proxyURL *url.URL // proxy URL, derived from proxy environment and target
mu sync.Mutex // protects all the fields below
targetResolverState *resolver.State // state of the target resolver
proxyAddrs []resolver.Address // resolved proxy addresses; empty if no proxy is configured
}
// nopResolver is a resolver that does nothing.
type nopResolver struct{}
func (nopResolver) ResolveNow(resolver.ResolveNowOptions) {}
func (nopResolver) Close() {}
// proxyURLForTarget determines the proxy URL for the given address based on
// the environment. It can return the following:
// - nil URL, nil error: No proxy is configured or the address is excluded
// using the `NO_PROXY` environment variable or if req.URL.Host is
// "localhost" (with or without // a port number)
// - nil URL, non-nil error: An error occurred while retrieving the proxy URL.
// - non-nil URL, nil error: A proxy is configured, and the proxy URL was
// retrieved successfully without any errors.
func proxyURLForTarget(address string) (*url.URL, error) {
req := &http.Request{URL: &url.URL{
Scheme: "https",
Host: address,
}}
return HTTPSProxyFromEnvironment(req)
}
// New creates a new delegating resolver that can create up to two child
// resolvers:
// - one to resolve the proxy address specified using the supported
// environment variables. This uses the registered resolver for the "dns"
// scheme.
// - one to resolve the target URI using the resolver specified by the scheme
// in the target URI or specified by the user using the WithResolvers dial
// option. As a special case, if the target URI's scheme is "dns" and a
// proxy is specified using the supported environment variables, the target
// URI's path portion is used as the resolved address unless target
// resolution is enabled using the dial option.
func New(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions, targetResolverBuilder resolver.Builder, targetResolutionEnabled bool) (resolver.Resolver, error) {
r := &delegatingResolver{
target: target,
cc: cc,
}
var err error
r.proxyURL, err = proxyURLForTarget(target.Endpoint())
if err != nil {
return nil, fmt.Errorf("delegating_resolver: failed to determine proxy URL for target %s: %v", target, err)
}
// proxy is not configured or proxy address excluded using `NO_PROXY` env
// var, so only target resolver is used.
if r.proxyURL == nil {
return targetResolverBuilder.Build(target, cc, opts)
}
if logger.V(2) {
logger.Infof("Proxy URL detected : %s", r.proxyURL)
}
// When the scheme is 'dns' and target resolution on client is not enabled,
// resolution should be handled by the proxy, not the client. Therefore, we
// bypass the target resolver and store the unresolved target address.
if target.URL.Scheme == "dns" && !targetResolutionEnabled {
state := resolver.State{
Addresses: []resolver.Address{{Addr: target.Endpoint()}},
Endpoints: []resolver.Endpoint{{Addresses: []resolver.Address{{Addr: target.Endpoint()}}}},
}
r.targetResolverState = &state
} else {
wcc := &wrappingClientConn{
stateListener: r.updateTargetResolverState,
parent: r,
}
if r.targetResolver, err = targetResolverBuilder.Build(target, wcc, opts); err != nil {
return nil, fmt.Errorf("delegating_resolver: unable to build the resolver for target %s: %v", target, err)
}
}
if r.proxyResolver, err = r.proxyURIResolver(opts); err != nil {
return nil, fmt.Errorf("delegating_resolver: failed to build resolver for proxy URL %q: %v", r.proxyURL, err)
}
if r.targetResolver == nil {
r.targetResolver = nopResolver{}
}
if r.proxyResolver == nil {
r.proxyResolver = nopResolver{}
}
return r, nil
}
// proxyURIResolver creates a resolver for resolving proxy URIs using the
// "dns" scheme. It adjusts the proxyURL to conform to the "dns:///" format and
// builds a resolver with a wrappingClientConn to capture resolved addresses.
func (r *delegatingResolver) proxyURIResolver(opts resolver.BuildOptions) (resolver.Resolver, error) {
proxyBuilder := resolver.Get("dns")
if proxyBuilder == nil {
panic("delegating_resolver: resolver for proxy not found for scheme dns")
}
url := *r.proxyURL
url.Scheme = "dns"
url.Path = "/" + r.proxyURL.Host
url.Host = "" // Clear the Host field to conform to the "dns:///" format
proxyTarget := resolver.Target{URL: url}
wcc := &wrappingClientConn{
stateListener: r.updateProxyResolverState,
parent: r,
}
return proxyBuilder.Build(proxyTarget, wcc, opts)
}
func (r *delegatingResolver) ResolveNow(o resolver.ResolveNowOptions) {
r.targetResolver.ResolveNow(o)
r.proxyResolver.ResolveNow(o)
}
func (r *delegatingResolver) Close() {
r.targetResolver.Close()
r.targetResolver = nil
r.proxyResolver.Close()
r.proxyResolver = nil
}
// updateClientConnStateLocked creates a list of combined addresses by
// pairing each proxy address with every target address. For each pair, it
// generates a new [resolver.Address] using the proxy address, and adding the
// target address as the attribute along with user info. It returns nil if
// either resolver has not sent update even once and returns the error from
// ClientConn update once both resolvers have sent update atleast once.
func (r *delegatingResolver) updateClientConnStateLocked() error {
if r.targetResolverState == nil || r.proxyAddrs == nil {
return nil
}
curState := *r.targetResolverState
// If multiple resolved proxy addresses are present, we send only the
// unresolved proxy host and let net.Dial handle the proxy host name
// resolution when creating the transport. Sending all resolved addresses
// would increase the number of addresses passed to the ClientConn and
// subsequently to load balancing (LB) policies like Round Robin, leading
// to additional TCP connections. However, if there's only one resolved
// proxy address, we send it directly, as it doesn't affect the address
// count returned by the target resolver and the address count sent to the
// ClientConn.
var proxyAddr resolver.Address
if len(r.proxyAddrs) == 1 {
proxyAddr = r.proxyAddrs[0]
} else {
proxyAddr = resolver.Address{Addr: r.proxyURL.Host}
}
var addresses []resolver.Address
for _, targetAddr := range (*r.targetResolverState).Addresses {
addresses = append(addresses, proxyattributes.Set(proxyAddr, proxyattributes.Options{
User: r.proxyURL.User,
ConnectAddr: targetAddr.Addr,
}))
}
// Create a list of combined endpoints by pairing all proxy endpoints
// with every target endpoint. Each time, it constructs a new
// [resolver.Endpoint] using the all addresses from all the proxy endpoint
// and the target addresses from one endpoint. The target address and user
// information from the proxy URL are added as attributes to the proxy
// address.The resulting list of addresses is then grouped into endpoints,
// covering all combinations of proxy and target endpoints.
var endpoints []resolver.Endpoint
for _, endpt := range (*r.targetResolverState).Endpoints {
var addrs []resolver.Address
for _, proxyAddr := range r.proxyAddrs {
for _, targetAddr := range endpt.Addresses {
addrs = append(addrs, proxyattributes.Set(proxyAddr, proxyattributes.Options{
User: r.proxyURL.User,
ConnectAddr: targetAddr.Addr,
}))
}
}
endpoints = append(endpoints, resolver.Endpoint{Addresses: addrs})
}
// Use the targetResolverState for its service config and attributes
// contents. The state update is only sent after both the target and proxy
// resolvers have sent their updates, and curState has been updated with
// the combined addresses.
curState.Addresses = addresses
curState.Endpoints = endpoints
return r.cc.UpdateState(curState)
}
// updateProxyResolverState updates the proxy resolver state by storing proxy
// addresses and endpoints, marking the resolver as ready, and triggering a
// state update if both proxy and target resolvers are ready. If the ClientConn
// returns a non-nil error, it calls `ResolveNow()` on the target resolver. It
// is a StateListener function of wrappingClientConn passed to the proxy resolver.
func (r *delegatingResolver) updateProxyResolverState(state resolver.State) error {
r.mu.Lock()
defer r.mu.Unlock()
if logger.V(2) {
logger.Infof("Addresses received from proxy resolver: %s", state.Addresses)
}
if len(state.Endpoints) > 0 {
// We expect exactly one address per endpoint because the proxy
// resolver uses "dns" resolution.
r.proxyAddrs = make([]resolver.Address, 0, len(state.Endpoints))
for _, endpoint := range state.Endpoints {
r.proxyAddrs = append(r.proxyAddrs, endpoint.Addresses...)
}
} else if state.Addresses != nil {
r.proxyAddrs = state.Addresses
} else {
r.proxyAddrs = []resolver.Address{} // ensure proxyAddrs is non-nil to indicate an update has been received
}
err := r.updateClientConnStateLocked()
// Another possible approach was to block until updates are received from
// both resolvers. But this is not used because calling `New()` triggers
// `Build()` for the first resolver, which calls `UpdateState()`. And the
// second resolver hasn't sent an update yet, so it would cause `New()` to
// block indefinitely.
if err != nil {
r.targetResolver.ResolveNow(resolver.ResolveNowOptions{})
}
return err
}
// updateTargetResolverState updates the target resolver state by storing target
// addresses, endpoints, and service config, marking the resolver as ready, and
// triggering a state update if both resolvers are ready. If the ClientConn
// returns a non-nil error, it calls `ResolveNow()` on the proxy resolver. It
// is a StateListener function of wrappingClientConn passed to the target resolver.
func (r *delegatingResolver) updateTargetResolverState(state resolver.State) error {
r.mu.Lock()
defer r.mu.Unlock()
if logger.V(2) {
logger.Infof("Addresses received from target resolver: %v", state.Addresses)
}
r.targetResolverState = &state
err := r.updateClientConnStateLocked()
if err != nil {
r.proxyResolver.ResolveNow(resolver.ResolveNowOptions{})
}
return nil
}
// wrappingClientConn serves as an intermediary between the parent ClientConn
// and the child resolvers created here. It implements the resolver.ClientConn
// interface and is passed in that capacity to the child resolvers.
type wrappingClientConn struct {
// Callback to deliver resolver state updates
stateListener func(state resolver.State) error
parent *delegatingResolver
}
// UpdateState receives resolver state updates and forwards them to the
// appropriate listener function (either for the proxy or target resolver).
func (wcc *wrappingClientConn) UpdateState(state resolver.State) error {
return wcc.stateListener(state)
}
// ReportError intercepts errors from the child resolvers and passes them to ClientConn.
func (wcc *wrappingClientConn) ReportError(err error) {
wcc.parent.cc.ReportError(err)
}
// NewAddress intercepts the new resolved address from the child resolvers and
// passes them to ClientConn.
func (wcc *wrappingClientConn) NewAddress(addrs []resolver.Address) {
wcc.UpdateState(resolver.State{Addresses: addrs})
}
// ParseServiceConfig parses the provided service config and returns an
// object that provides the parsed config.
func (wcc *wrappingClientConn) ParseServiceConfig(serviceConfigJSON string) *serviceconfig.ParseResult {
return wcc.parent.cc.ParseServiceConfig(serviceConfigJSON)
}