Sync fork with upstream master.

.github/ISSUE_TEMPLATE/bug.md

@@ -5,7 +5,8 @@ labels: 'Type: Bug'
 
 ---
 
-Please answer these questions before submitting your issue.
+Please see the FAQ in our main README.md, then answer the questions below before
+submitting your issue.
 
 ### What version of gRPC are you using?
 

.github/ISSUE_TEMPLATE/feature.md

@@ -5,6 +5,8 @@ labels: 'Type: Feature'
 
 ---
 
+Please see the FAQ in our main README.md before submitting your issue.
+
 ### Use case(s) - what problem will this feature solve?
 
 ### Proposed Solution

.github/ISSUE_TEMPLATE/question.md

@@ -4,3 +4,5 @@ about: Ask a question about gRPC-Go
 labels: 'Type: Question'
 
 ---
+
+Please see the FAQ in our main README.md before submitting your issue.

CONTRIBUTING.md

@@ -11,27 +11,50 @@ In order to protect both you and ourselves, you will need to sign the
 
 ## Guidelines for Pull Requests
 How to get your contributions merged smoothly and quickly.
-
-- Create **small PRs** that are narrowly focused on **addressing a single concern**. We often times receive PRs that are trying to fix several things at a time, but only one fix is considered acceptable, nothing gets merged and both author's & review's time is wasted. Create more PRs to address different concerns and everyone will be happy.
-
-- For speculative changes, consider opening an issue and discussing it first. If you are suggesting a behavioral or API change, consider starting with a [gRFC proposal](https://github.com/grpc/proposal). 
-
-- Provide a good **PR description** as a record of **what** change is being made and **why** it was made. Link to a github issue if it exists.
-
-- Don't fix code style and formatting unless you are already changing that line to address an issue. PRs with irrelevant changes won't be merged. If you do want to fix formatting or style, do that in a separate PR.
-
-- Unless your PR is trivial, you should expect there will be reviewer comments that you'll need to address before merging. We expect you to be reasonably responsive to those comments, otherwise the PR will be closed after 2-3 weeks of inactivity.
-
-- Maintain **clean commit history** and use **meaningful commit messages**. PRs with messy commit history are difficult to review and won't be merged. Use `rebase -i upstream/master` to curate your commit history and/or to bring in latest changes from master (but avoid rebasing in the middle of a code review).
-
-- Keep your PR up to date with upstream/master (if there are merge conflicts, we can't really merge your change).
-
-- **All tests need to be passing** before your change can be merged. We recommend you **run tests locally** before creating your PR to catch breakages early on.
+
+- Create **small PRs** that are narrowly focused on **addressing a single
+  concern**. We often times receive PRs that are trying to fix several things at
+  a time, but only one fix is considered acceptable, nothing gets merged and
+  both author's & review's time is wasted. Create more PRs to address different
+  concerns and everyone will be happy.
+
+- The grpc package should only depend on standard Go packages and a small number
+  of exceptions. If your contribution introduces new dependencies which are NOT
+  in the [list](https://godoc.org/google.golang.org/grpc?imports), you need a
+  discussion with gRPC-Go authors and consultants.
+
+- For speculative changes, consider opening an issue and discussing it first. If
+  you are suggesting a behavioral or API change, consider starting with a [gRFC
+  proposal](https://github.com/grpc/proposal).
+
+- Provide a good **PR description** as a record of **what** change is being made
+  and **why** it was made. Link to a github issue if it exists.
+
+- Don't fix code style and formatting unless you are already changing that line
+  to address an issue. PRs with irrelevant changes won't be merged. If you do
+  want to fix formatting or style, do that in a separate PR.
+
+- Unless your PR is trivial, you should expect there will be reviewer comments
+  that you'll need to address before merging. We expect you to be reasonably
+  responsive to those comments, otherwise the PR will be closed after 2-3 weeks
+  of inactivity.
+
+- Maintain **clean commit history** and use **meaningful commit messages**. PRs
+  with messy commit history are difficult to review and won't be merged. Use
+  `rebase -i upstream/master` to curate your commit history and/or to bring in
+  latest changes from master (but avoid rebasing in the middle of a code
+  review).
+
+- Keep your PR up to date with upstream/master (if there are merge conflicts, we
+  can't really merge your change).
+
+- **All tests need to be passing** before your change can be merged. We
+  recommend you **run tests locally** before creating your PR to catch breakages
+  early on.
   - `make all` to test everything, OR
   - `make vet` to catch vet errors
   - `make test` to run the tests
   - `make testrace` to run tests in race mode
   - optional `make testappengine` to run tests with appengine
 
 - Exceptions to the rules can be made if there's a compelling reason for doing so.
-

Documentation/keepalive.md

@@ -35,7 +35,7 @@ for details.
 ### Enforcement policy
 
 [Enforcement
-policy](https://godoc.org/google.golang.org/grpc/keepalive#ServerParameters) is
+policy](https://godoc.org/google.golang.org/grpc/keepalive#EnforcementPolicy) is
 a special setting on server side to protect server from malicious or misbehaving
 clients.
 

Documentation/rpc-errors.md

@@ -65,4 +65,4 @@ exit status 1
 [details]:      https://godoc.org/google.golang.org/grpc/status#Status.Details
 [status-err]:   https://godoc.org/google.golang.org/grpc/status#Status.Err
 [status-error]: https://godoc.org/google.golang.org/grpc/status#Error
-[example]:      https://github.com/grpc/grpc-go/blob/master/examples/rpc_errors
+[example]:      https://github.com/grpc/grpc-go/tree/master/examples/features/errors

README.md

@@ -1,42 +1,96 @@
 # gRPC-Go
 
-[![Build Status](https://travis-ci.org/grpc/grpc-go.svg)](https://travis-ci.org/grpc/grpc-go) [![GoDoc](https://godoc.org/google.golang.org/grpc?status.svg)](https://godoc.org/google.golang.org/grpc) [![GoReportCard](https://goreportcard.com/badge/grpc/grpc-go)](https://goreportcard.com/report/github.com/grpc/grpc-go)
+[![Build Status](https://travis-ci.org/grpc/grpc-go.svg)](https://travis-ci.org/grpc/grpc-go)
+[![GoDoc](https://godoc.org/google.golang.org/grpc?status.svg)](https://godoc.org/google.golang.org/grpc)
+[![GoReportCard](https://goreportcard.com/badge/grpc/grpc-go)](https://goreportcard.com/report/github.com/grpc/grpc-go)
 
-The Go implementation of [gRPC](https://grpc.io/): A high performance, open source, general RPC framework that puts mobile and HTTP/2 first. For more information see the [gRPC Quick Start: Go](https://grpc.io/docs/quickstart/go.html) guide.
+The Go implementation of [gRPC](https://grpc.io/): A high performance, open
+source, general RPC framework that puts mobile and HTTP/2 first. For more
+information see the [gRPC Quick Start:
+Go](https://grpc.io/docs/quickstart/go.html) guide.
 
 Installation
 ------------
 
-To install this package, you need to install Go and setup your Go workspace on your computer. The simplest way to install the library is to run:
+To install this package, you need to install Go and setup your Go workspace on
+your computer. The simplest way to install the library is to run:
 
 ```
 $ go get -u google.golang.org/grpc
 ```
 
+With Go module support (Go 1.11+), simply `import "google.golang.org/grpc"` in
+your source code and `go [build|run|test]` will automatically download the
+necessary dependencies ([Go modules
+ref](https://github.com/golang/go/wiki/Modules)).
+
+If you are trying to access grpc-go from within China, please see the
+[FAQ](#FAQ) below.
+
 Prerequisites
 -------------
-
 gRPC-Go requires Go 1.9 or later.
 
-Constraints
------------
-The grpc package should only depend on standard Go packages and a small number of exceptions. If your contribution introduces new dependencies which are NOT in the [list](https://godoc.org/google.golang.org/grpc?imports), you need a discussion with gRPC-Go authors and consultants.
-
 Documentation
 -------------
-See [API documentation](https://godoc.org/google.golang.org/grpc) for package and API descriptions and find examples in the [examples directory](examples/).
+- See [godoc](https://godoc.org/google.golang.org/grpc) for package and API
+  descriptions.
+- Documentation on specific topics can be found in the [Documentation
+  directory](Documentation/).
+- Examples can be found in the [examples directory](examples/).
 
 Performance
 -----------
-See the current benchmarks for some of the languages supported in [this dashboard](https://performance-dot-grpc-testing.appspot.com/explore?dashboard=5652536396611584&widget=490377658&container=1286539696).
+Performance benchmark data for grpc-go and other languages is maintained in
+[this
+dashboard](https://performance-dot-grpc-testing.appspot.com/explore?dashboard=5652536396611584&widget=490377658&container=1286539696).
 
 Status
 ------
-General Availability [Google Cloud Platform Launch Stages](https://cloud.google.com/terms/launch-stages).
+General Availability [Google Cloud Platform Launch
+Stages](https://cloud.google.com/terms/launch-stages).
 
 FAQ
 ---
 
+#### I/O Timeout Errors
+
+The `golang.org` domain may be blocked from some countries.  `go get` usually
+produces an error like the following when this happens:
+
+```
+$ go get -u google.golang.org/grpc
+package google.golang.org/grpc: unrecognized import path "google.golang.org/grpc" (https fetch: Get https://google.golang.org/grpc?go-get=1: dial tcp 216.239.37.1:443: i/o timeout)
+```
+
+To build Go code, there are several options:
+
+- Set up a VPN and access google.golang.org through that.
+
+- Without Go module support: `git clone` the repo manually:
+
+  ```
+  git clone https://github.com/grpc/grpc-go.git $GOPATH/src/google.golang.org/grpc
+  ```
+
+  You will need to do the same for all of grpc's dependencies in `golang.org`,
+  e.g. `golang.org/x/net`.
+
+- With Go module support: it is possible to use the `replace` feature of `go
+  mod` to create aliases for golang.org packages.  In your project's directory:
+
+  ```
+  go mod edit -replace=google.golang.org/grpc=github.com/grpc/grpc-go@latest
+  go mod tidy
+  go mod vendor
+  go build -mod=vendor
+  ```
+
+  Again, this will need to be done for all transitive dependencies hosted on
+  golang.org as well.  Please refer to [this
+  issue](https://github.com/golang/go/issues/28652) in the golang repo regarding
+  this concern.
+
 #### Compiling error, undefined: grpc.SupportPackageIsVersion
 
 Please update proto package, gRPC package and rebuild the proto files:

balancer/balancer.go

@@ -138,6 +138,8 @@ type ClientConn interface {
 	ResolveNow(resolver.ResolveNowOption)
 
 	// Target returns the dial target for this ClientConn.
+	//
+	// Deprecated: Use the Target field in the BuildOptions instead.
 	Target() string
 }
 
@@ -155,6 +157,10 @@ type BuildOptions struct {
 	Dialer func(context.Context, string) (net.Conn, error)
 	// ChannelzParentID is the entity parent's channelz unique identification number.
 	ChannelzParentID int64
+	// Target contains the parsed address info of the dial target. It is the same resolver.Target as
+	// passed to the resolver.
+	// See the documentation for the resolver.Target type for details about what it contains.
+	Target resolver.Target
 }
 
 // Builder creates a balancer.

balancer/grpclb/grpclb.go

@@ -28,7 +28,6 @@ import (
 	"context"
 	"errors"
 	"strconv"
-	"strings"
 	"sync"
 	"time"
 
@@ -129,19 +128,8 @@ func newLBBuilderWithFallbackTimeout(fallbackTimeout time.Duration) balancer.Bui
 	}
 }
 
-// newLBBuilderWithPickFirst creates a grpclb builder with pick-first.
-func newLBBuilderWithPickFirst() balancer.Builder {
-	return &lbBuilder{
-		usePickFirst: true,
-	}
-}
-
 type lbBuilder struct {
 	fallbackTimeout time.Duration
-
-	// TODO: delete this when balancer can handle service config. This should be
-	//  updated by service config.
-	usePickFirst bool // Use roundrobin or pickfirst for backends.
 }
 
 func (b *lbBuilder) Name() string {
@@ -155,19 +143,10 @@ func (b *lbBuilder) Build(cc balancer.ClientConn, opt balancer.BuildOptions) bal
 	scheme := "grpclb_internal_" + strconv.FormatInt(time.Now().UnixNano(), 36)
 	r := &lbManualResolver{scheme: scheme, ccb: cc}
 
-	var target string
-	targetSplitted := strings.Split(cc.Target(), ":///")
-	if len(targetSplitted) < 2 {
-		target = cc.Target()
-	} else {
-		target = targetSplitted[1]
-	}
-
 	lb := &lbBalancer{
 		cc:              newLBCacheClientConn(cc),
-		target:          target,
+		target:          opt.Target.Endpoint,
 		opt:             opt,
-		usePickFirst:    b.usePickFirst,
 		fallbackTimeout: b.fallbackTimeout,
 		doneCh:          make(chan struct{}),
 
@@ -231,11 +210,14 @@ type lbBalancer struct {
 	// serverList contains anything new. Each generate picker will also have
 	// reference to this list to do the first layer pick.
 	fullServerList []*lbpb.Server
+	// Backend addresses. It's kept so the addresses are available when
+	// switching between round_robin and pickfirst.
+	backendAddrs []resolver.Address
 	// All backends addresses, with metadata set to nil. This list contains all
 	// backend addresses in the same order and with the same duplicates as in
 	// serverlist. When generating picker, a SubConn slice with the same order
 	// but with only READY SCs will be gerenated.
-	backendAddrs []resolver.Address
+	backendAddrsWithoutMetadata []resolver.Address
 	// Roundrobin functionalities.
 	state    connectivity.State
 	subConns map[resolver.Address]balancer.SubConn   // Used to new/remove SubConn.
@@ -275,7 +257,7 @@ func (lb *lbBalancer) regeneratePicker(resetDrop bool) {
 			break
 		}
 	} else {
-		for _, a := range lb.backendAddrs {
+		for _, a := range lb.backendAddrsWithoutMetadata {
 			if sc, ok := lb.subConns[a]; ok {
 				if st, ok := lb.scStates[sc]; ok && st == connectivity.Ready {
 					readySCs = append(readySCs, sc)
@@ -339,6 +321,11 @@ func (lb *lbBalancer) aggregateSubConnStates() connectivity.State {
 }
 
 func (lb *lbBalancer) HandleSubConnStateChange(sc balancer.SubConn, s connectivity.State) {
+	panic("not used")
+}
+
+func (lb *lbBalancer) UpdateSubConnState(sc balancer.SubConn, scs balancer.SubConnState) {
+	s := scs.ConnectivityState
 	if grpclog.V(2) {
 		grpclog.Infof("lbBalancer: handle SubConn state change: %p, %v", sc, s)
 	}
@@ -371,7 +358,7 @@ func (lb *lbBalancer) HandleSubConnStateChange(sc balancer.SubConn, s connectivi
 	if lb.state != connectivity.Ready {
 		if !lb.inFallback && !lb.remoteBalancerConnected {
 			// Enter fallback.
-			lb.refreshSubConns(lb.resolvedBackendAddrs, false)
+			lb.refreshSubConns(lb.resolvedBackendAddrs, true, lb.usePickFirst)
 		}
 	}
 }
@@ -410,17 +397,38 @@ func (lb *lbBalancer) fallbackToBackendsAfter(fallbackTimeout time.Duration) {
 		return
 	}
 	// Enter fallback.
-	lb.refreshSubConns(lb.resolvedBackendAddrs, false)
+	lb.refreshSubConns(lb.resolvedBackendAddrs, true, lb.usePickFirst)
 	lb.mu.Unlock()
 }
 
 // HandleResolvedAddrs sends the updated remoteLB addresses to remoteLB
 // clientConn. The remoteLB clientConn will handle creating/removing remoteLB
 // connections.
 func (lb *lbBalancer) HandleResolvedAddrs(addrs []resolver.Address, err error) {
+	panic("not used")
+}
+
+func (lb *lbBalancer) handleServiceConfig(sc string) {
+	lb.mu.Lock()
+	defer lb.mu.Unlock()
+
+	newUsePickFirst := childIsPickFirst(sc)
+	if lb.usePickFirst == newUsePickFirst {
+		return
+	}
+	if grpclog.V(2) {
+		grpclog.Infof("lbBalancer: switching mode, new usePickFirst: %+v", newUsePickFirst)
+	}
+	lb.refreshSubConns(lb.backendAddrs, lb.inFallback, newUsePickFirst)
+}
+
+func (lb *lbBalancer) UpdateResolverState(rs resolver.State) {
 	if grpclog.V(2) {
-		grpclog.Infof("lbBalancer: handleResolvedResult: %+v", addrs)
+		grpclog.Infof("lbBalancer: UpdateResolverState: %+v", rs)
 	}
+	lb.handleServiceConfig(rs.ServiceConfig)
+
+	addrs := rs.Addresses
 	if len(addrs) <= 0 {
 		return
 	}
@@ -457,7 +465,7 @@ func (lb *lbBalancer) HandleResolvedAddrs(addrs []resolver.Address, err error) {
 		// This means we received a new list of resolved backends, and we are
 		// still in fallback mode. Need to update the list of backends we are
 		// using to the new list of backends.
-		lb.refreshSubConns(lb.resolvedBackendAddrs, false)
+		lb.refreshSubConns(lb.resolvedBackendAddrs, true, lb.usePickFirst)
 	}
 	lb.mu.Unlock()
 }