*: use Go 1.9+

[gyuho]

• Replace import paths of golang.org/x/net/context with context within etcd (done via *: deprecate 'golang.org/x/net/context' #8511)
• Coordinate with external projects that imports etcd packages with context packages
  • discovery, client, clientv3, raft
  • Communicate with Kubernetes (done via https://groups.google.com/d/msg/kubernetes-dev/_YcpsDSSOW0/Aifxsub-CQAJ)
  • Communicate with CockroachDB (done via FYI. coreos/etcd/raft deprecates 'golang.org/x/net/context' cockroachdb/cockroach#18348)
  • Communicate with dgraph (done via FYI. coreos/etcd/raft deprecates 'golang.org/x/net/context' dgraph-io/dgraph#1423)
  • Communicate with chain (done via FYI. coreos/etcd/raft deprecates 'golang.org/x/net/context' Onyx-Protocol/Onyx#1466)
• Request to replace golang.org/x/net/context with context in upstream dependencies
  • google.golang.org/grpc (Replace "golang.org/x/net/context" with "context" and stop supporting go1.6 grpc/grpc-go#1160)
  • github.com/golang/protobuf (TODO Question: move to Go 1.7+ stdlib 'context' package? golang/protobuf#336)
  • github.com/gogo/protobuf (TODO Any plan to switch Go standard package 'context' gogo/protobuf#282)
  • github.com/grpc-ecosystem/grpc-gateway (TODO Move to stdlib context grpc-ecosystem/grpc-gateway#343)
  • golang.org/x/time x/time/rate: use context package from Go 1.7+ golang/go#16745 (done via golang/time@c06e80d)
  • golang.org/x/net/trace (done via golang/net@c8c7437)
• fix all other issues with staticcheck (done via pkg/transport, rafthttp: CancelableTransport #7602)
• io.Seek* *: use 'os.SEEK_*' #6296
• use time.Until (done via *: clean up for Go 1.8+ #7737)
• tls.Config copy method https://golang.org/pkg/crypto/tls/#Config.Clone to replace ShallowCopyTLSConfig at https://github.com/coreos/etcd/blob/master/pkg/transport/listener.go (done via *: clean up for Go 1.8+ #7737)
• add mutex profile handler to embed/serve.go https://golang.org/pkg/runtime/pprof/#Profile (done via pkg/debugutil: add 'mutex' profiler (Go 1.8+) #7765)
• *url.URL.Hostname(), *url.URL.Port() https://golang.org/doc/go1.8#net_url (done via embed: use '*url.URL.Hostname(),Port()' for Go 1.8 #7766)
• Graceful shutdown gRPC server; see boltdb panic while removing member from cluster #7322 (comment) (done via *: use gRPC server GracefulStop #7743)
• CloseNotify in ServeHTTP net/http: closeNotify does not work well when read timeout is set golang/go#9524 (comment) (not needed for etcd use case?)
• http.Server.Shutdown https://golang.org/doc/go1.8#http_shutdown (done via embed: gracefully close peer handler #7879)
• Use net.DialContext, http.Transport.DialContext in pkg/transport (TODO: done via pkg/transport, rafthttp: CancelableTransport #7602)
• Use http.Request.WithContext for httputil.RequestCanceler
• Use monotime (done via lease: use monotime in time.Time for Go 1.9 #8507)

[xiang90]

move to 3.2. we will release 3.2 with go 1.8.

[lukaszo]

This hack https://github.com/coreos/etcd/blob/master/pkg/transport/transport.go#L66-L71 doesn't work with 1.8 anymore :(

[gyuho]

Moving to 3.3. Hopefully, Go 1.9 addresses golang/protobuf#336.

[gyuho]

Closing and opening a new issue on contexts in generated code.