This update provides:
1) workaround around the build failures. In
summary, it forces the download of some packages during the build
process.
2) update the set of packages that should go inside the vendor
directory
3) Update the dockerfile to use go 1.10
Change-Id: I2bfd090ce0f25b0c10aa214755ae2da7e5384d60
diff --git a/vendor/github.com/coreos/etcd/raft/node.go b/vendor/github.com/coreos/etcd/raft/node.go
new file mode 100644
index 0000000..33a9db8
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/raft/node.go
@@ -0,0 +1,539 @@
+// Copyright 2015 The etcd 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 raft
+
+import (
+ "context"
+ "errors"
+
+ pb "github.com/coreos/etcd/raft/raftpb"
+)
+
+type SnapshotStatus int
+
+const (
+ SnapshotFinish SnapshotStatus = 1
+ SnapshotFailure SnapshotStatus = 2
+)
+
+var (
+ emptyState = pb.HardState{}
+
+ // ErrStopped is returned by methods on Nodes that have been stopped.
+ ErrStopped = errors.New("raft: stopped")
+)
+
+// SoftState provides state that is useful for logging and debugging.
+// The state is volatile and does not need to be persisted to the WAL.
+type SoftState struct {
+ Lead uint64 // must use atomic operations to access; keep 64-bit aligned.
+ RaftState StateType
+}
+
+func (a *SoftState) equal(b *SoftState) bool {
+ return a.Lead == b.Lead && a.RaftState == b.RaftState
+}
+
+// Ready encapsulates the entries and messages that are ready to read,
+// be saved to stable storage, committed or sent to other peers.
+// All fields in Ready are read-only.
+type Ready struct {
+ // The current volatile state of a Node.
+ // SoftState will be nil if there is no update.
+ // It is not required to consume or store SoftState.
+ *SoftState
+
+ // The current state of a Node to be saved to stable storage BEFORE
+ // Messages are sent.
+ // HardState will be equal to empty state if there is no update.
+ pb.HardState
+
+ // ReadStates can be used for node to serve linearizable read requests locally
+ // when its applied index is greater than the index in ReadState.
+ // Note that the readState will be returned when raft receives msgReadIndex.
+ // The returned is only valid for the request that requested to read.
+ ReadStates []ReadState
+
+ // Entries specifies entries to be saved to stable storage BEFORE
+ // Messages are sent.
+ Entries []pb.Entry
+
+ // Snapshot specifies the snapshot to be saved to stable storage.
+ Snapshot pb.Snapshot
+
+ // CommittedEntries specifies entries to be committed to a
+ // store/state-machine. These have previously been committed to stable
+ // store.
+ CommittedEntries []pb.Entry
+
+ // Messages specifies outbound messages to be sent AFTER Entries are
+ // committed to stable storage.
+ // If it contains a MsgSnap message, the application MUST report back to raft
+ // when the snapshot has been received or has failed by calling ReportSnapshot.
+ Messages []pb.Message
+
+ // MustSync indicates whether the HardState and Entries must be synchronously
+ // written to disk or if an asynchronous write is permissible.
+ MustSync bool
+}
+
+func isHardStateEqual(a, b pb.HardState) bool {
+ return a.Term == b.Term && a.Vote == b.Vote && a.Commit == b.Commit
+}
+
+// IsEmptyHardState returns true if the given HardState is empty.
+func IsEmptyHardState(st pb.HardState) bool {
+ return isHardStateEqual(st, emptyState)
+}
+
+// IsEmptySnap returns true if the given Snapshot is empty.
+func IsEmptySnap(sp pb.Snapshot) bool {
+ return sp.Metadata.Index == 0
+}
+
+func (rd Ready) containsUpdates() bool {
+ return rd.SoftState != nil || !IsEmptyHardState(rd.HardState) ||
+ !IsEmptySnap(rd.Snapshot) || len(rd.Entries) > 0 ||
+ len(rd.CommittedEntries) > 0 || len(rd.Messages) > 0 || len(rd.ReadStates) != 0
+}
+
+// Node represents a node in a raft cluster.
+type Node interface {
+ // Tick increments the internal logical clock for the Node by a single tick. Election
+ // timeouts and heartbeat timeouts are in units of ticks.
+ Tick()
+ // Campaign causes the Node to transition to candidate state and start campaigning to become leader.
+ Campaign(ctx context.Context) error
+ // Propose proposes that data be appended to the log.
+ Propose(ctx context.Context, data []byte) error
+ // ProposeConfChange proposes config change.
+ // At most one ConfChange can be in the process of going through consensus.
+ // Application needs to call ApplyConfChange when applying EntryConfChange type entry.
+ ProposeConfChange(ctx context.Context, cc pb.ConfChange) error
+ // Step advances the state machine using the given message. ctx.Err() will be returned, if any.
+ Step(ctx context.Context, msg pb.Message) error
+
+ // Ready returns a channel that returns the current point-in-time state.
+ // Users of the Node must call Advance after retrieving the state returned by Ready.
+ //
+ // NOTE: No committed entries from the next Ready may be applied until all committed entries
+ // and snapshots from the previous one have finished.
+ Ready() <-chan Ready
+
+ // Advance notifies the Node that the application has saved progress up to the last Ready.
+ // It prepares the node to return the next available Ready.
+ //
+ // The application should generally call Advance after it applies the entries in last Ready.
+ //
+ // However, as an optimization, the application may call Advance while it is applying the
+ // commands. For example. when the last Ready contains a snapshot, the application might take
+ // a long time to apply the snapshot data. To continue receiving Ready without blocking raft
+ // progress, it can call Advance before finishing applying the last ready.
+ Advance()
+ // ApplyConfChange applies config change to the local node.
+ // Returns an opaque ConfState protobuf which must be recorded
+ // in snapshots. Will never return nil; it returns a pointer only
+ // to match MemoryStorage.Compact.
+ ApplyConfChange(cc pb.ConfChange) *pb.ConfState
+
+ // TransferLeadership attempts to transfer leadership to the given transferee.
+ TransferLeadership(ctx context.Context, lead, transferee uint64)
+
+ // ReadIndex request a read state. The read state will be set in the ready.
+ // Read state has a read index. Once the application advances further than the read
+ // index, any linearizable read requests issued before the read request can be
+ // processed safely. The read state will have the same rctx attached.
+ ReadIndex(ctx context.Context, rctx []byte) error
+
+ // Status returns the current status of the raft state machine.
+ Status() Status
+ // ReportUnreachable reports the given node is not reachable for the last send.
+ ReportUnreachable(id uint64)
+ // ReportSnapshot reports the status of the sent snapshot.
+ ReportSnapshot(id uint64, status SnapshotStatus)
+ // Stop performs any necessary termination of the Node.
+ Stop()
+}
+
+type Peer struct {
+ ID uint64
+ Context []byte
+}
+
+// StartNode returns a new Node given configuration and a list of raft peers.
+// It appends a ConfChangeAddNode entry for each given peer to the initial log.
+func StartNode(c *Config, peers []Peer) Node {
+ r := newRaft(c)
+ // become the follower at term 1 and apply initial configuration
+ // entries of term 1
+ r.becomeFollower(1, None)
+ for _, peer := range peers {
+ cc := pb.ConfChange{Type: pb.ConfChangeAddNode, NodeID: peer.ID, Context: peer.Context}
+ d, err := cc.Marshal()
+ if err != nil {
+ panic("unexpected marshal error")
+ }
+ e := pb.Entry{Type: pb.EntryConfChange, Term: 1, Index: r.raftLog.lastIndex() + 1, Data: d}
+ r.raftLog.append(e)
+ }
+ // Mark these initial entries as committed.
+ // TODO(bdarnell): These entries are still unstable; do we need to preserve
+ // the invariant that committed < unstable?
+ r.raftLog.committed = r.raftLog.lastIndex()
+ // Now apply them, mainly so that the application can call Campaign
+ // immediately after StartNode in tests. Note that these nodes will
+ // be added to raft twice: here and when the application's Ready
+ // loop calls ApplyConfChange. The calls to addNode must come after
+ // all calls to raftLog.append so progress.next is set after these
+ // bootstrapping entries (it is an error if we try to append these
+ // entries since they have already been committed).
+ // We do not set raftLog.applied so the application will be able
+ // to observe all conf changes via Ready.CommittedEntries.
+ for _, peer := range peers {
+ r.addNode(peer.ID)
+ }
+
+ n := newNode()
+ n.logger = c.Logger
+ go n.run(r)
+ return &n
+}
+
+// RestartNode is similar to StartNode but does not take a list of peers.
+// The current membership of the cluster will be restored from the Storage.
+// If the caller has an existing state machine, pass in the last log index that
+// has been applied to it; otherwise use zero.
+func RestartNode(c *Config) Node {
+ r := newRaft(c)
+
+ n := newNode()
+ n.logger = c.Logger
+ go n.run(r)
+ return &n
+}
+
+// node is the canonical implementation of the Node interface
+type node struct {
+ propc chan pb.Message
+ recvc chan pb.Message
+ confc chan pb.ConfChange
+ confstatec chan pb.ConfState
+ readyc chan Ready
+ advancec chan struct{}
+ tickc chan struct{}
+ done chan struct{}
+ stop chan struct{}
+ status chan chan Status
+
+ logger Logger
+}
+
+func newNode() node {
+ return node{
+ propc: make(chan pb.Message),
+ recvc: make(chan pb.Message),
+ confc: make(chan pb.ConfChange),
+ confstatec: make(chan pb.ConfState),
+ readyc: make(chan Ready),
+ advancec: make(chan struct{}),
+ // make tickc a buffered chan, so raft node can buffer some ticks when the node
+ // is busy processing raft messages. Raft node will resume process buffered
+ // ticks when it becomes idle.
+ tickc: make(chan struct{}, 128),
+ done: make(chan struct{}),
+ stop: make(chan struct{}),
+ status: make(chan chan Status),
+ }
+}
+
+func (n *node) Stop() {
+ select {
+ case n.stop <- struct{}{}:
+ // Not already stopped, so trigger it
+ case <-n.done:
+ // Node has already been stopped - no need to do anything
+ return
+ }
+ // Block until the stop has been acknowledged by run()
+ <-n.done
+}
+
+func (n *node) run(r *raft) {
+ var propc chan pb.Message
+ var readyc chan Ready
+ var advancec chan struct{}
+ var prevLastUnstablei, prevLastUnstablet uint64
+ var havePrevLastUnstablei bool
+ var prevSnapi uint64
+ var rd Ready
+
+ lead := None
+ prevSoftSt := r.softState()
+ prevHardSt := emptyState
+
+ for {
+ if advancec != nil {
+ readyc = nil
+ } else {
+ rd = newReady(r, prevSoftSt, prevHardSt)
+ if rd.containsUpdates() {
+ readyc = n.readyc
+ } else {
+ readyc = nil
+ }
+ }
+
+ if lead != r.lead {
+ if r.hasLeader() {
+ if lead == None {
+ r.logger.Infof("raft.node: %x elected leader %x at term %d", r.id, r.lead, r.Term)
+ } else {
+ r.logger.Infof("raft.node: %x changed leader from %x to %x at term %d", r.id, lead, r.lead, r.Term)
+ }
+ propc = n.propc
+ } else {
+ r.logger.Infof("raft.node: %x lost leader %x at term %d", r.id, lead, r.Term)
+ propc = nil
+ }
+ lead = r.lead
+ }
+
+ select {
+ // TODO: maybe buffer the config propose if there exists one (the way
+ // described in raft dissertation)
+ // Currently it is dropped in Step silently.
+ case m := <-propc:
+ m.From = r.id
+ r.Step(m)
+ case m := <-n.recvc:
+ // filter out response message from unknown From.
+ if pr := r.getProgress(m.From); pr != nil || !IsResponseMsg(m.Type) {
+ r.Step(m) // raft never returns an error
+ }
+ case cc := <-n.confc:
+ if cc.NodeID == None {
+ r.resetPendingConf()
+ select {
+ case n.confstatec <- pb.ConfState{Nodes: r.nodes()}:
+ case <-n.done:
+ }
+ break
+ }
+ switch cc.Type {
+ case pb.ConfChangeAddNode:
+ r.addNode(cc.NodeID)
+ case pb.ConfChangeAddLearnerNode:
+ r.addLearner(cc.NodeID)
+ case pb.ConfChangeRemoveNode:
+ // block incoming proposal when local node is
+ // removed
+ if cc.NodeID == r.id {
+ propc = nil
+ }
+ r.removeNode(cc.NodeID)
+ case pb.ConfChangeUpdateNode:
+ r.resetPendingConf()
+ default:
+ panic("unexpected conf type")
+ }
+ select {
+ case n.confstatec <- pb.ConfState{Nodes: r.nodes()}:
+ case <-n.done:
+ }
+ case <-n.tickc:
+ r.tick()
+ case readyc <- rd:
+ if rd.SoftState != nil {
+ prevSoftSt = rd.SoftState
+ }
+ if len(rd.Entries) > 0 {
+ prevLastUnstablei = rd.Entries[len(rd.Entries)-1].Index
+ prevLastUnstablet = rd.Entries[len(rd.Entries)-1].Term
+ havePrevLastUnstablei = true
+ }
+ if !IsEmptyHardState(rd.HardState) {
+ prevHardSt = rd.HardState
+ }
+ if !IsEmptySnap(rd.Snapshot) {
+ prevSnapi = rd.Snapshot.Metadata.Index
+ }
+
+ r.msgs = nil
+ r.readStates = nil
+ advancec = n.advancec
+ case <-advancec:
+ if prevHardSt.Commit != 0 {
+ r.raftLog.appliedTo(prevHardSt.Commit)
+ }
+ if havePrevLastUnstablei {
+ r.raftLog.stableTo(prevLastUnstablei, prevLastUnstablet)
+ havePrevLastUnstablei = false
+ }
+ r.raftLog.stableSnapTo(prevSnapi)
+ advancec = nil
+ case c := <-n.status:
+ c <- getStatus(r)
+ case <-n.stop:
+ close(n.done)
+ return
+ }
+ }
+}
+
+// Tick increments the internal logical clock for this Node. Election timeouts
+// and heartbeat timeouts are in units of ticks.
+func (n *node) Tick() {
+ select {
+ case n.tickc <- struct{}{}:
+ case <-n.done:
+ default:
+ n.logger.Warningf("A tick missed to fire. Node blocks too long!")
+ }
+}
+
+func (n *node) Campaign(ctx context.Context) error { return n.step(ctx, pb.Message{Type: pb.MsgHup}) }
+
+func (n *node) Propose(ctx context.Context, data []byte) error {
+ return n.step(ctx, pb.Message{Type: pb.MsgProp, Entries: []pb.Entry{{Data: data}}})
+}
+
+func (n *node) Step(ctx context.Context, m pb.Message) error {
+ // ignore unexpected local messages receiving over network
+ if IsLocalMsg(m.Type) {
+ // TODO: return an error?
+ return nil
+ }
+ return n.step(ctx, m)
+}
+
+func (n *node) ProposeConfChange(ctx context.Context, cc pb.ConfChange) error {
+ data, err := cc.Marshal()
+ if err != nil {
+ return err
+ }
+ return n.Step(ctx, pb.Message{Type: pb.MsgProp, Entries: []pb.Entry{{Type: pb.EntryConfChange, Data: data}}})
+}
+
+// Step advances the state machine using msgs. The ctx.Err() will be returned,
+// if any.
+func (n *node) step(ctx context.Context, m pb.Message) error {
+ ch := n.recvc
+ if m.Type == pb.MsgProp {
+ ch = n.propc
+ }
+
+ select {
+ case ch <- m:
+ return nil
+ case <-ctx.Done():
+ return ctx.Err()
+ case <-n.done:
+ return ErrStopped
+ }
+}
+
+func (n *node) Ready() <-chan Ready { return n.readyc }
+
+func (n *node) Advance() {
+ select {
+ case n.advancec <- struct{}{}:
+ case <-n.done:
+ }
+}
+
+func (n *node) ApplyConfChange(cc pb.ConfChange) *pb.ConfState {
+ var cs pb.ConfState
+ select {
+ case n.confc <- cc:
+ case <-n.done:
+ }
+ select {
+ case cs = <-n.confstatec:
+ case <-n.done:
+ }
+ return &cs
+}
+
+func (n *node) Status() Status {
+ c := make(chan Status)
+ select {
+ case n.status <- c:
+ return <-c
+ case <-n.done:
+ return Status{}
+ }
+}
+
+func (n *node) ReportUnreachable(id uint64) {
+ select {
+ case n.recvc <- pb.Message{Type: pb.MsgUnreachable, From: id}:
+ case <-n.done:
+ }
+}
+
+func (n *node) ReportSnapshot(id uint64, status SnapshotStatus) {
+ rej := status == SnapshotFailure
+
+ select {
+ case n.recvc <- pb.Message{Type: pb.MsgSnapStatus, From: id, Reject: rej}:
+ case <-n.done:
+ }
+}
+
+func (n *node) TransferLeadership(ctx context.Context, lead, transferee uint64) {
+ select {
+ // manually set 'from' and 'to', so that leader can voluntarily transfers its leadership
+ case n.recvc <- pb.Message{Type: pb.MsgTransferLeader, From: transferee, To: lead}:
+ case <-n.done:
+ case <-ctx.Done():
+ }
+}
+
+func (n *node) ReadIndex(ctx context.Context, rctx []byte) error {
+ return n.step(ctx, pb.Message{Type: pb.MsgReadIndex, Entries: []pb.Entry{{Data: rctx}}})
+}
+
+func newReady(r *raft, prevSoftSt *SoftState, prevHardSt pb.HardState) Ready {
+ rd := Ready{
+ Entries: r.raftLog.unstableEntries(),
+ CommittedEntries: r.raftLog.nextEnts(),
+ Messages: r.msgs,
+ }
+ if softSt := r.softState(); !softSt.equal(prevSoftSt) {
+ rd.SoftState = softSt
+ }
+ if hardSt := r.hardState(); !isHardStateEqual(hardSt, prevHardSt) {
+ rd.HardState = hardSt
+ }
+ if r.raftLog.unstable.snapshot != nil {
+ rd.Snapshot = *r.raftLog.unstable.snapshot
+ }
+ if len(r.readStates) != 0 {
+ rd.ReadStates = r.readStates
+ }
+ rd.MustSync = MustSync(rd.HardState, prevHardSt, len(rd.Entries))
+ return rd
+}
+
+// MustSync returns true if the hard state and count of Raft entries indicate
+// that a synchronous write to persistent storage is required.
+func MustSync(st, prevst pb.HardState, entsnum int) bool {
+ // Persistent state on all servers:
+ // (Updated on stable storage before responding to RPCs)
+ // currentTerm
+ // votedFor
+ // log entries[]
+ return entsnum != 0 || st.Vote != prevst.Vote || st.Term != prevst.Term
+}